6,431 results
Search Results
2. Portable and Visual Detection of Cytochrome c with Graphene Quantum Dots–Filter Paper Composite
- Author
-
Liangtong Li, Yongjian Jiang, Ni Wang, Yusheng Feng, Binbin Chen, and Jian Wang
- Subjects
graphene quantum dots ,cytochrome c ,apoptosis ,inner filter effect ,portable ,filter paper ,Biochemistry ,QD415-436 - Abstract
As a significant biomarker during the apoptosis process, cytochrome c (Cyt c) is considered as a critical component in the inherent apoptotic pathway, but the simple and portable detection still remains challengeable. In this work, a portable and visual sensing platform for Cyt c was developed based upon the fluorescence quenching of graphene quantum dots (GQDs), which could be finished within a few seconds. Herein, the absorption spectrum of Cyt c matched the emission spectrum of GQDs well, which could cause the fluorescence quenching of GQDs via the inner filter effect (IFE) in the range of 1–50 μg/mL with the limit of detection as low as 0.1 μg/mL. Furthermore, the intracellular Cyt c was imaged to observe the apoptosis process of cancer cells induced by staurosporine. To achieve the portable and visual detection of Cyt c, GQDs were deposited on the filter paper to form the solid platform, which displayed a gradual fluorescence quenching when different concentrations of Cyt c were present. Compared to the conventional methods, the proposed assay is low-cost, fast, portable, and visual, which will be useful for the investigation of mitochondrial dysfunction and apoptotic cell death.
- Published
- 2024
- Full Text
- View/download PDF
3. Colorimetric and electrochemical dual-signal detection of uracil-DNA glycosylase using functionalized pure DNA hydrogel on paper-based analytical devices
- Author
-
Wei Xue, Pan Jia, Yunping Wu, Pu Wang, Jiarong Shi, Yangyang Chang, and Meng Liu
- Subjects
Pure DNA hydrogel ,Uracil-DNA glycosylase ,Dual-signal detection ,Rolling circle amplification ,Paper-based analytical device ,Agriculture (General) ,S1-972 ,Biochemistry ,QD415-436 ,Chemistry ,QD1-999 - Abstract
The development of simple and accurate detection of uracil-DNA glycosylase (UDG) is of great significance for early clinical diagnosis and biomedical research. Here, we on the first effort introduced the uracil bases into the rolling circle amplification (RCA) reaction to produce the functionalized pure DNA hydrogel (PDH) for UDG detection. During RCA process, methylene blue (MB) molecules as the indicators were encapsulated into PDH. The addition of UDG can remove the uracil bases of PDH to generate abasic sites, which are further cleaved with the assistance of apurinic/apyrimidinic endonuclease (APE), thus resulting in the dissociation of PDH to release blue MB. By combining with the paper analytical devices as the signal readout platform, a colorimetric and electrochemical dual-signal biosensor was constructed for convenient and accurate detection of UDG. The proposed MB@PDH-based dual-signal sensing system exhibited good selectivity and high sensitivity with a detection limit of 6.4 × 10−4 U/mL (electrochemical method). It was also demonstrated that this sensing system showed excellent performance in UDG inhibitor screening, thus providing great potential in UDG-related disease diagnosis and drug discovery.
- Published
- 2023
- Full Text
- View/download PDF
4. Supramolecular systems based on chitosan and chemically functionalized nanocelluloses as protective and reinforcing fillers of paper structure
- Author
-
Lorenzo Lisuzzo, Giuseppe Cavallaro, Giuseppe Lazzara, and Stefana Milioto
- Subjects
Nanocellulose ,Chitosan ,Electrostatic Interactions ,ITC ,Paper consolidation ,Biochemistry ,QD415-436 - Abstract
Supramolecular systems based on chitosan and cellulose nanofibers (CNFs) with a different surface modification (TEMPO-oxidation and carboxymethylation) were investigated and utilized for the functional consolidation of paper. Prior to the paper consolidation, the interactions between chitosan and CNFs dispersed in aqueous solvent were studied. It was detected that the peculiar surface functionalization of nanocellulose is crucial to control the chitosan/CNFs electrostatic attractions and, consequently, the entropic/enthalpic contributions and the stoichiometry of the biopolymer adsorption onto the cellulose nanofibers. Dynamic Light Scattering and rheological experiments revealed that the presence of biopolymeric chains on the CNFs surface favors the entanglement and the aggregation between the nanofibers reinforcing their network. It was observed that chitosan and nanocellulose exhibit synergetic effects on the paper consolidation in terms of reinforcing action, surface hydrophobization and enhancement of the fire-resistance. In conclusion, this paper demonstrates that the electrostatic interactions between chitosan and functionalized nanocellulose drive the formation of hybrid fillers suitable for paper consolidation. Chitosan coated CNFs possess an improved capacity to penetrate the paper structure causing an enhancement of the mechanical resistance and surface hydrophobization. Moreover, chitosan/CNFs create a protective barrier for heat transfer that prevents the paper combustion.
- Published
- 2023
- Full Text
- View/download PDF
5. Origami Paper-Based Electrochemical Immunosensor with Carbon Nanohorns-Decorated Nanoporous Gold for Zearalenone Detection
- Author
-
Anabel Laza, Sirley V. Pereira, Germán A. Messina, Martín A. Fernández-Baldo, Julio Raba, Matías D. Regiart, and Franco A. Bertolino
- Subjects
paper-based ,electrochemical ,immunosensor ,carbon nanohorns ,nanoporous gold ,mycotoxin ,Biochemistry ,QD415-436 - Abstract
Nowadays, mycotoxin contamination in cereals and wastewater exposes a safety hazard to consumer health. This work describes the design of a simple, low-cost, and sensitive origami microfluidic paper-based device using electrochemical detection for zearalenone determination. The microfluidic immunosensor was designed on a paper platform by a wax printing process. The graphitized carbon working electrode modified with carbon nanohorns-decorated nanoporous gold showed a higher surface area, sensitivity, and adequate analytical performance. Electrodes were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and cyclic voltammetry. The determination of zearalenone was carried out through a competitive immunoassay using specific antibodies immobilized by a covalent bond on the electrode surface. In the presence of HRP-labeled enzyme conjugate, substrate, and catechol, zearalenone was detected employing the developed immunosensor by applying −0.1 V to the working electrode vs silver as a pseudo-reference electrode. A calibration curve with a linear range between 10 and 1000 µg Kg−1 (R2 = 0.998) was obtained, and the limit of detection and quantification for the electrochemical immunosensor were 4.40 and 14.90 µg Kg−1, respectively. The coefficient of variation for intra- and inter-day assays was less than 5%. The selectivity and specificity of the sensor were evaluated, comparing the response against zearalenone metabolites and other mycotoxins that could affect the corn samples. Therefore, origami is a promising approach for paper-based electrochemical microfluidic sensors coupled to smartphones as a rapid and portable tool for in situ mycotoxins detection in real samples.
- Published
- 2024
- Full Text
- View/download PDF
6. Advancing Paper Industry Applications with Extruded Cationic Wheat Starch as an Environmentally Friendly Biopolymer
- Author
-
Ahmed Tara
- Subjects
cationic wheat starch ,twin-screw reactive extrusion ,degree of substitution ,papermaking ,specific mechanical energy ,viscosity ,Biochemistry ,QD415-436 - Abstract
Within the domain of starch modification, the study delved into cationization of wheat starch through a laboratory-scale twin-screw extruder, exploring various processing conditions. Cationic starch, a crucial component for enhancing paper attributes like dry strength and printability, took center stage. The focus shifted towards integration into papermaking, investigating the transformative potential of reactive extrusion. By contrasting it with conventional dry-process methodology, innovative strides were unveiled. The study extended to pilot-scale extrusion, bridging the gap between laboratory experimentation and potential industrial implementation. Infused with scientific rigor, the investigation navigated the benefits brought about by reactive extrusion. Empirical insights highlighted a significant reduction in the intrinsic viscosity of extruded starch, decreasing from 170 mL·g−1 (native starch) to 100 mL·g−1 at a specific mechanical energy (SME) input of 800 kWh·t−1, demonstrating remarkable stability despite increased mechanical treatment. Moreover, beyond the critical threshold of 220 kWh·t−1, retention efficiency reached a stable plateau at 78%. The study revealed that utilizing a larger extruder slightly improved the mechanical properties of the paper, emphasizing the advantage of scaling up the production process and the consistency of results across different extruder sizes.
- Published
- 2023
- Full Text
- View/download PDF
7. The Psychosocial Effects of the Flint Water Crisis on School-Age Children. Working Paper 29341
- Author
-
National Bureau of Economic Research, Trejo, Sam, Yeomans-Maldonado, Gloria, and Jacob, Brian
- Abstract
Lead poisoning has well-known impacts for the developing brain of young children, with a large literature documenting the negative effects of elevated blood lead levels on academic and behavioral outcomes. In April of 2014, the municipal water source in Flint, Michigan was changed, causing lead from aging pipes to leach into the city's drinking water. In this study, we use Michigan's universe of longitudinal, student-level education records, combined with home water service line inspection data containing the location of lead pipes, to empirically examine the effect of the Flint Water Crisis on educational outcomes of Flint public school children. We leverage parallel causal identification strategies, a between-district synthetic control analysis and a within-Flint difference-in-differences analysis, to separate out the direct health effects of lead exposure from the broad effects of living in a community experiencing a crisis. Our results highlight a less well-appreciated consequence of the Flint Water Crisis -- namely, the psychosocial effects of the crisis on the educational outcomes of school-age children. These findings suggest that cost estimates which rely only on the negative impact of direct lead exposure substantially underestimate the overall societal cost of the crisis.
- Published
- 2021
8. Third Military Medical University - Army Medical University Researchers Update Knowledge of Biosensors (Multiarmed DNA jumper and metal-organic frameworks-functionalized paper-based bioplatform for small extracellular vesicle-derived miRNAs ...)
- Subjects
Biochemistry ,Medical equipment ,Biosensors ,DNA ,Genetic research ,MicroRNA ,Physiological apparatus ,Physical fitness ,Health - Abstract
2024 JUN 15 (NewsRx) -- By a News Reporter-Staff News Editor at Obesity, Fitness & Wellness Week -- Research findings on biosensors are discussed in a new report. According to [...]
- Published
- 2024
9. Novel Electrochemical Sensor Based on MnO2 Nanowire Modified Carbon Paper Electrode for Sensitive Determination of Tetrabromobisphenol A
- Author
-
Chunmao Zhu, Qi Wu, Fanshu Yuan, Jie Liu, Dongtian Wang, and Qianli Zhang
- Subjects
tetrabromobisphenol A ,MnO2 ,carbon paper ,modified electrode ,Biochemistry ,QD415-436 - Abstract
In this paper, a MnO2 nanowire (MnO2-NW) modified carbon paper electrode (CP) was developed as a novel electrochemical sensor for the sensitive determination of tetrabromobisphenol A (TBBPA). The MnO2 nanowire was prepared by a hydrothermal synthesis method, and the morphology and structure of MnO2 were characterized using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical performance of TBBPA on MnO2-NW/CP was investigated by cyclic voltammetry, and the result confirmed that MnO2-NW/CP exhibited excellent sensitivity for the determination of TBBPA due to the high specific surface area and good electrical conductivity of the nanowire-like MnO2. Moreover, the important electrochemical factors such as pH value, incubation time and modified material proportion were systematically studied to improve the determination sensitivity. The interferences from similar structure compounds on TBBPA have also been investigated. Under the optimal conditions, MnO2-NW/CP displayed a linear range of 70~500 nM for TBBPA with a detection limit of 3.1 nM. This was superior to some electrochemical methods in reference. The work presents a novel and simple method for the determination of TBBPA.
- Published
- 2023
- Full Text
- View/download PDF
10. Recent Advances and Perspectives Regarding Paper-Based Sensors for Salivary Biomarker Detection
- Author
-
Cong Chen, Lulu Tian, Wen Li, Kun Wang, Qijing Yang, Jinying Lin, Tianshou Zhang, Biao Dong, and Lin Wang
- Subjects
paper-based sensor ,saliva biomarker ,point of care ,Biochemistry ,QD415-436 - Abstract
Paper-based sensors overcome the drawbacks of conventional sensors in terms of their flexibility, portability, and stability compared to conventional sensors. Moreover, as a noninvasive bodily fluid, saliva contains various biomarkers related to physical status, which makes it perfectly matched with to use of paper-based sensors to manufacture a convenient and inexpensive disposable sensing device. This review focuses on the recent advances and progress in the design of paper-based salivary sensors and their applications. The first part mainly discusses various paper-based sensors and their advanced compositions, including dipstick assay, lateral flow assay, and microfluidic analytical device. Different detection methods in salivary biomarker detection are specially introduced in the secondary section, then their multiple potential applications and prospects are summarized. The sensor has excellent advantages for saliva detection, provides a reliable platform for point-of-care tests and telemedicine, and epically promotes the development of the medical Internet of Things.
- Published
- 2023
- Full Text
- View/download PDF
11. Highly Crystalline Oxidase-like MnOOH Nanowire-Incorporated Paper Dipstick for One-Step Colorimetric Detection of Dopamine
- Author
-
Phan Ba Khanh Chau, Thinh Viet Dang, and Moon Il Kim
- Subjects
paper dipstick ,MnOOH nanowires ,dopamine oxidase ,nanozyme ,colorimetric biosensors ,Biochemistry ,QD415-436 - Abstract
Developing a convenient detection method for dopamine holds a significant incentive due to its high clinical significance. Herein, we synthesize crystalline MnOOH nanowires (MNWs) via a simple solvothermal treatment of KMnO4 and demonstrate that they possess excellent oxidase-like activity owing to the presence of pure Mn3+ sites on the MNWs. Particularly, MNWs catalyze the rapid oxidation of dopamine into aminochromes, which show a vivid brown color. The dopamine oxidase-like activity of MNWs follows the typical Michaelis–Mentenkinetics with excellent storage stability. Based on the affirmative catalytic features, a paper dipstick incorporating MNWs in the detection zone is constructed for the one-step colorimetric detection of target dopamine. By immersing the dipstick into the sample solution for 30 min, the sample spontaneously moves to the detection zone due to capillary force, yielding a brown color proportional to the amount of dopamine, which is quantified from an image acquired using a smartphone. With the MNW-containing solution-based assay and MNW-incorporated paper dipstick, dopamine is successfully determined with high selectivity, sensitivity, and detection precision when using spiked human serum and pharmaceutical dopamine injection samples, respectively. Successful analytical values such as the dynamic linear ranges of 3–60 μM and 0.05–7 mM are achieved with the solution-based assay and paper dipstick, respectively, along with excellent detection accuracy (95–99%) and precision (1.0–3.1%). Hence, we developed a simple and efficient nanozyme-based paper dipstick biosensor for dopamine that can be used in point-of-care testing environments.
- Published
- 2023
- Full Text
- View/download PDF
12. Low-Cost, High-Sensitivity Paper-Based Bacteria Impedance Sensor Based on Vertical Flow Assay
- Author
-
Yifan Long, Zhehong Ai, Longhan Zhang, Han Zhang, Jing Jiang, and Gang Logan Liu
- Subjects
paper-based electrode ,bacterial detection ,portable sensor ,on-site detection ,Biochemistry ,QD415-436 - Abstract
This study proposes a low-cost, portable paper-fluidic vertical flow assay bacterium counter with high accuracy. We designed sensors with low fabrication costs based on e-beam evaporation and three-dimensional printing based on the impedance measurement principle. Interdigitated (IDT) electrodes were coated on the filter membrane by e-beam evaporation with a shadow mask. We could print wafer-scale frames with low melting temperature three-dimensional-printing materials for confining liquid bacterial samples within the IDT sensing region. This novel fabrication technique significantly reduced the chip’s cost to less than 1% of that of silicon-based chips. Two equivalent circuit models were proposed for different concentration ranges to analyze the principle of paper-based impedance bacterial sensors. We proposed an improved model based on the Randles model for low concentrations by considering the leaky double-layer capacitor effect and spherical diffusion from the nano-structural electrodes of the gold-coated filter membrane. The phenomenon in which charge transfer resistance, Rct, declines at high concentration ranges was found and explained by the pearl chain effect. The pearl effect could cause a false-negative at high concentrations. We modeled the pearl chain effect as an R and C, connected parallel to the low-concentration model. When users properly applied both models for analyses, this sensor could quantitatively measure cell concentrations from 400 to 400 M per milliliter with superior linearity.
- Published
- 2023
- Full Text
- View/download PDF
13. Paper-Based Loop Mediated Isothermal Amplification (LAMP) Platforms: Integrating the Versatility of Paper Microfluidics with Accuracy of Nucleic Acid Amplification Tests
- Author
-
Debayan Das, Manaswini Masetty, and Aashish Priye
- Subjects
LAMP ,RT-LAMP ,paper-based diagnostics ,point-of-care diagnostics ,Biochemistry ,QD415-436 - Abstract
Paper-based diagnostics offer a promising alternative to traditional diagnostic methods for point-of-care use due to their low cost, ease of use, portability, rapid results, versatility, and low environmental impact. While paper-based serology tests in the form of lateral flow assays can provide rapid test results for past pathogen exposure, they currently lack the accuracy and sensitivity offered by molecular diagnostic tests such as the polymerase chain reaction (PCR). Loop-mediated isothermal amplification (LAMP)—an isothermal nucleic acid amplification test (NAAT)—provides PCR-like performance while simultaneously reducing the instrumentation and assay complexity associated with PCR. In this review, we discuss a newly emerging class of paper-based LAMP platforms that integrates the versatility of paper microfluidics with the accuracy of NAATs. Since its first adoption in 2015, we have discussed all paper-based LAMP platforms in terms of the paper substrates, reagent incorporation techniques, paper platform design, heating hardware, detection methods, and sensitivity and specificity of paper-based LAMP assays. We conclude by identifying the current challenges and future prospects of paper-based NAATs.
- Published
- 2023
- Full Text
- View/download PDF
14. Iron Determination in Natural Waters Using a Synthesised 3-Hydroxy-4-Pyridione Ligand in a Newly Developed Microfluidic Paper-Based Device
- Author
-
Juliana I. S. Aguiar, Susana O. Ribeiro, Andreia Leite, Maria Rangel, António O. S. S. Rangel, and Raquel B. R. Mesquita
- Subjects
iron quantification sensor ,microfluidic paper-based analytical device ,3-hydroxy-4-pyridinone ligand ,natural waters ,in situ analysis ,Biochemistry ,QD415-436 - Abstract
This work describes the development of an iron sensor based on a microfluidic paper-based technique, to attain iron quantification in natural waters. A new water-soluble naphthalene-3-hydroxy-4-pyridione ligand was used as a colour reagent, as it formed an orange complex with iron. As a newly described ligand, several chemical and physical parameters, namely, the sample and reagent volumes and reagent concentrations, were studied related to the formation of the coloured complex. The microfluidic paper-based analytical device (μPAD) assembly, namely, the use of different types of filter paper and different numbers of layers, was developed to obtain the best performance. Under the optimal conditions, a linear correlation was obtained in the range of 0.25–2.00 mg/L of iron, with a minimum detectable value of 0.07 mg/L. The proposed μPAD method was validated by an analysis of the certified samples and by a comparison of the tested water samples with the inductively coupled plasma (ICP) results (RE < 10%). Then, the μPAD device was successfully applied to the determination of iron in tap water, well water, river water, and seawater, with no need for any prior sample pre-treatment; recovery studies were also performed (average = 100.3% with RSD = 4.2%).
- Published
- 2023
- Full Text
- View/download PDF
15. A Paper-Chip-Based Phage Biosensor Combined with a Smartphone Platform for the Quick and On-Site Analysis of E. coli O157:H7 in Foods
- Author
-
Chaiyong Wu, Dengfeng Li, Qianli Jiang, and Ning Gan
- Subjects
POCT assay ,paper-chip-based phage biosensor ,smartphone ,E. coli O157:H7 ,foods ,Biochemistry ,QD415-436 - Abstract
The rapid and specific point-of-care (POC) analysis of virulent pathogenic strains plays a key role in ensuring food quality and safety. In this work, a paper-based fluorescent phage biosensor was developed for the detection of the virulent E. coli O157:H7 strain (as the mode of virulent pathogens) in food samples. Firstly, phages that can specifically combine with E. coli O157:H7 (E. coli) were stained with SYTO-13 dye to prepare a novel fluorescent probe (phage@SYTO). Simultaneously, a micro-porous membrane filter with a pore size of 0.45 μm was employed as a paper chip so as to retain the E. coli-phage@SYTO complex (>1.2 μm) on its surface. The phage@SYTO (200 nm in size) was able to pass through the pores of the chip, and the complex could be retained on the paper chip using the free phage@SYTO probes. The E. coli-phage@SYTO could emit a visual fluorescent signal (excited at 365 nm; emitted at 520 nm) onto the chip, which could be detected by a smartphone to reflect the concentration of E. coli. Under optimized conditions, the detection limit was as low as 50 CFU/mL (S/N = 3) and exhibited a wide linear range from 102 to 106 CFU/mL. The sensor has potential application value for the quick and specific POCT detection of virulent E. coli in foods.
- Published
- 2023
- Full Text
- View/download PDF
16. Correction: Wu et al. A Novel Truncated DNAzyme Modified Paper Analytical Device for Point-of-Care Test of Copper Ions in Natural Waters. Chemosensors 2022, 10, 72
- Author
-
Jiayi Wu, Ming Wang, Huanhuan Hong, Jianyuan Lin, Ning Gan, and Wenchao Bi
- Subjects
n/a ,Biochemistry ,QD415-436 - Abstract
The authors make the following corrections to the published paper [...]
- Published
- 2024
- Full Text
- View/download PDF
17. Utilization of bio-polymeric additives for a sustainable production strategy in pulp and paper manufacturing: A comprehensive review
- Author
-
Soumya Basu, Shuank Malik, Gyanesh Joshi, P.K. Gupta, and Vikas Rana
- Subjects
Cellulose and derivatives ,Hemicelluloses ,Starch and derivatives ,Bio-polymeric additive ,Pulp and paper manufacturing ,Paper industries ,Biochemistry ,QD415-436 - Abstract
Renewable and bio-based materials have gained great interest on an industrial scale owing to environmental issues. Paper industries also are constantly exploring bio-resources for intrinsic chemico-physical property enhancement of paper and paper products. These bio-resources will potentially increase their cyclability besides making paper compatible beyond traditional uses. Mechanical beating or use of chemical additives or the combination of these methods are widely used to improve critical paper characteristics such as strength, surface smoothness, density, brightness, filler retention, water and grease resistivity etc. These chemical additives as mill effluents are hazardous and have detrimental effect on environment. So, to move ahead of traditional practices, the present review discusses about the production and utility of abundantly available renewable bio-polymers and their products such as starch, cellulose, plant-based proteins, microbial biopolymers, animal-based biopolymers, and natural gums etc. They represent ample prospect in terms of research and development on their functionality and industrial applications.
- Published
- 2021
- Full Text
- View/download PDF
18. Paper-Based Analytical Device for One-Step Detection of Bisphenol-A Using Functionalized Chitosan
- Author
-
Abdelhafid Karrat and Aziz Amine
- Subjects
chitosan ,smartphone ,paper-based analytical devices ,one-step detection ,bisphenol-A ,Biochemistry ,QD415-436 - Abstract
Bisphenol-A (BPA) is defined as one of the endocrine disrupting compounds. The accurate and inexpensive colorimetric paper-based analytical devices (PADs) are of crucial importance for BPA analysis. In this context, we developed for the first time a new PAD modified with chitosan and sulfamethoxazole (Chitosan-PAD) for the visual detection of BPA in water. The PAD was characterized by Fourier-transform infrared spectroscopy, which confirmed its modification by the functionalized chitosan. A yellow coloration was developed when a small volume of BPA was added to the Chitosan-PAD, allowing for visual and smartphone detection. This new strategy is based on a specific combination of BPA with chitosan and sulfamethoxazole that provides a hight selectivity to the Chitosan-PAD. The proposed PAD was successfully employed in combination with a pre-concentration step for the detection of 0.01 µg mL−1 of PBA with the naked eye using a 10-fold preconcentration factor. The PAD was effectively applied for BPA quantification in water samples with good recoveries. The developed PAD provides a green and cost-effective strategy for the on-site and one-step detection of BPA in water samples.
- Published
- 2022
- Full Text
- View/download PDF
19. Evaluating process of auto-hydrolysis prior to kraft pulping on production of chemical pulp for end used paper-grade products
- Author
-
Wenchao Jia, Miaofang Zhou, Chenfeng Yang, He Zhang, Meihong Niu, and Haiqiang Shi
- Subjects
Auto-hydrolysis ,Kraft pulping ,Pulping performance ,Fiber morphology ,Black liquor ,Biochemistry ,QD415-436 - Abstract
The objective of this work is to systematically evaluate the performance of the hydrolysis-based kraft pulping process and associated pulp and black liquor characteristics. Acacia wood chips were auto-hydrolyzed under various severities, then the hydrolyzed wood chips were kraft pulping. The results indicated that the yield of pulp significantly dropped with intensifying the auto-hydrolysis severity. Meanwhile, the removal rate of pentosan reached 98.6% in the screened pulp at the P-factor of 1 000. The fiber length, fines and fiber crimp of the screened pulp were not affected by the auto-hydrolysis treatment. Auto-hydrolyzed pulps deteriorated fibrillation and beating response of the pulp in a refining process. However, fiber length and fines changed obviously after beating treatment. After auto-hydrolysis, the tensile index of the paper matrices decreased, some particle substances were found on the surface of the pulp fiber, and the solid and organic content of the black liquor were improved.
- Published
- 2022
- Full Text
- View/download PDF
20. Fabrication of cellulose nanocrystal (CNC) from waste paper for developing antifouling and high-performance polyvinylidene fluoride (PVDF) membrane for water purification
- Author
-
Pankaj Boruah, Raghvendra Gupta, and Vimal Katiyar
- Subjects
Cellulose nanocrystal ,Polyvinylidene fluoride ,Hydrophilic ,Antifouling ability ,Biochemistry ,QD415-436 - Abstract
Waste papers are used as a source of raw material to fabricate cellulose nanocrystals (CNCs), a highly valued product with a high degree of crystallinity. Rod-shaped CNCs with an average diameter of 53 ± 9 nm and an average length of 234 ± 42 nm were obtained with a crystallinity of around 78%. Polyvinylidene fluoride (PVDF) thin composite membrane was developed by adding CNCs into the PVDF matrix in different amounts (0, 0.5, 1, 1.5, 2, 3 wt%). Porous finger-like structures in the membrane increased with an increase in CNC content. The FTIR measurement and high-resolution FESEM image of the membranes verified the presence of CNCs in the composite membranes. 48% high pure water flux (PWF) was obtained for PVDF/CNC as compared to pristine PVDF membrane with the addition of 3% CNCs at a pressure of 1 kg−1cm−2. Water contact angle (WCA) also decreased from 85° to 69° with increasing the wt% of CNCs in the dope solution, which signifies improved hydrophilicity. Further, the PVDF/CNCs membrane showed a high bovine serum albumin (BSA) rejection of 93% and a flux recovery ratio (FRR) of 76.76 %, whereas the pristine PVDF membrane showed BSA rejection of 70.86% and a FRR of 40.82 %, respectively.
- Published
- 2023
- Full Text
- View/download PDF
21. An Economical and Portable Paper-Based Colorimetric Sensor for the Determination of Hydrogen Peroxide-Related Biomarkers
- Author
-
Wei-Yi Zhang, Hao Zhang, and Feng-Qing Yang
- Subjects
paper-based analytical device ,colorimetric sensor ,point-of-care testing ,iodide ,glucose oxidase ,Biochemistry ,QD415-436 - Abstract
In this study, a paper-based sensor was developed for the detection of hydrogen-peroxide-related biomarkers, with glucose oxidase catalyzing as an example. Potassium iodide can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine in the presence of hydrogen peroxide to colorize the paper-based biosensor detection area, which was imaged by a scanner, and the color intensity was analyzed by the Adobe Photoshop. Under the optimal conditions, the color intensity shows a good linear relationship with hydrogen peroxide and glucose concentrations in the ranges of 0.1–5.0 mM and 0.5–6.0 mM, respectively. The detection limit of hydrogen peroxide is 0.03 mM and the limit of quantification of glucose is 0.5 mM. Besides, the method was employed in measuring glucose concentration in fruit samples, and the spiked recoveries are in the range of 95.4–106.1%. This method is cost-effective, environmentally friendly, and easy to be operated, which is expected to realize the point-of-care testing of more hydrogen-peroxide-related biomarkers.
- Published
- 2022
- Full Text
- View/download PDF
22. Development of a Paper-Based Analytical Method for the Selective Colorimetric Determination of Bismuth in Water Samples
- Author
-
Panagiotis A. Bizirtsakis, Maria Tarara, Apostolia Tsiasioti, Paraskevas D. Tzanavaras, and George Z. Tsogas
- Subjects
paper-based analytical devices ,colorimetric determination ,bismuth ,methyl thymol blue ,water samples ,Biochemistry ,QD415-436 - Abstract
A novel, direct and simple colorimetric method employing μicroanalytical paper-based devices (μ-PADs) for the selective determination of bismuth is described. The suggested method exploits the colorimetric variation of bismuth after its rapid reaction with methyl thymol blue (MTB) in an acidic medium (pH ranging between 0.7 and 3.0), modified with nitric acid, on the surface of a paper device at room temperature. The devices are low cost, composed of chromatographic paper and wax barriers and the analytical protocol is easily applicable with minimal technical expertise and without the need for experimental apparatus. The user must add a test sample and read the color intensity of the colored Bi(III)–MTB complex formed at the sensing area using a simple imaging device such as a flatbed scanner. Various chemical variables, such as HNO3 and MTB concentration, reaction time, ionic strength, detection zone size and photo-capture detector are optimized. A study of interfering ions such as K+, Na+, Ca2+, Mg2+, Cl−, SO42− and HCO3− was also conducted. The stability of the paper devices is also studied in different maintenance conditions with particularly satisfactory results, rendering the method suitable for field analysis. The detection limits are as low as 3.0 mg L−1 with very satisfactory precision, ranging from 4.0% (intra-day) to 5.5% (inter-day). Natural water samples are successfully analyzed, and bismuth percentage recoveries were calculated in the range of 82.8 to 115.4%.
- Published
- 2022
- Full Text
- View/download PDF
23. Position Paper Progress in the development of biomimetic engineered human tissues
- Author
-
Umber Cheema
- Subjects
Biochemistry ,QD415-436 - Abstract
Tissue engineering (TE) is the multi-disciplinary approach to building 3D human tissue equivalents in the laboratory. The advancement of medical sciences and allied scientific disciplines have aspired to engineer human tissues for three decades. To date there is limited use of TE tissues/organs as replacement body parts in humans. This position paper outlines advances in engineering of specific tissues and organs with tissue-specific challenges. This paper outlines the technologies most successful for engineering tissues and key areas of advancement.
- Published
- 2023
- Full Text
- View/download PDF
24. Wax-Printed Fluidic Controls for Delaying and Accelerating Fluid Transport on Paper-Based Analytical Devices
- Author
-
Maria Tarara, Dimosthenis L. Giokas, and George Z. Tsogas
- Subjects
paper-based analytical devices ,wax-printed barriers ,fluid control ,delay and acceleration of fluid flow ,enzymatic assay of glucose ,Biochemistry ,QD415-436 - Abstract
In this work, we explore a new method for controlling fluid transport rate on paper-based analytical devices that enables both the delay and the acceleration of fluid flow. The delays were incorporated by wax printing linear patterns of variable width within the flow channel and melted to penetrate the paper. In this manner, the surface tension of the fluid decreases while its contact angle increases, causing a pressure drop along the fluid path that reduces capillary flow. The acceleration of flow was accomplished by overlaying hydrophobic stripes (prepared by wax printing and melting the wax) on the hydrophilic path (top or top–bottom). In this manner, the fluid was repelled from two dimensions (vertical and applicate), increasing the flow rate. The combination of these methods on the same devices could adjust wicking time in intermediate time internals. The method enabled a wide timing of fluid transport, accomplishing a change in wicking times that extended from −41% to +259% compared to open paper channels. As a proof of concept, an enzymatic assay of glucose was used to demonstrate the utility of these fluid control methods in kinetic methods of analysis.
- Published
- 2022
- Full Text
- View/download PDF
25. A Paper-Based Multicolor Colorimetric Aptasensor for the Visual Determination of Multiple Sulfonamides Based on Aptamer-Functionalized Magnetic Beads and NADH–Ascorbic Acid-Mediated Gold Nanobipyramids
- Author
-
Meiling Ping, Wenchao Lv, Chen Yang, Qian Chen, Zongwen Wang, and Fengfu Fu
- Subjects
aptasensor ,antibiotics residue ,seafood ,sulfonamides ,visual detection ,Biochemistry ,QD415-436 - Abstract
It is crucial that simple and high-throughput methods for determining multiple, or groups of, sulfonamides (SAs) be developed since they are widely used in animal husbandry and aquaculture. We developed a paper-based multicolor colorimetric aptasensor to detect 3 SAs: sulfaquinoxaline (SQ), sulfamethoxypyridazine (SMP) and sulfamethoxydiazine (SMD). Using a broad-specificity aptamer as a bioreceptor, we reduced the growth of nicotinamide adenine dinucleotide I (NADH)–ascorbic acid (AA)-mediated gold nanobipyramids (AuNBPs) to generate a multicolor signal. We also used a paper-based analytical device (PAD) system to deposit AuNBPs for a sensitive color signal read out. The aptasensor can detect more color changes corresponding to the concentrations of SQ, SMP and SMD and has higher sensitivity, better specificity and stability. It can also be used to determine SQ, SMP and SDM individually, or collectively, or any two together with a visual detection limit of 0.3–1.0 µM, a spectrometry quantification limit (LOQ) of 0.3–0.5 µM and a spectrometry detection limits (LOD) of 0.09–0.15 µM. The aptasensor was successfully used to determine SQ, SMP and SDM in fish muscle with a recovery of 89–94% and a RSD n = 5) < 8%, making it a promising method for the rapid screening of total SQ, SMP and SDM residue in seafood.
- Published
- 2023
- Full Text
- View/download PDF
26. In Situ Detection of Hydrogen Sulfide in 3D-Cultured, Live Prostate Cancer Cells Using a Paper-Integrated Analytical Device
- Author
-
Jae-Hyung Kim, Young-Ju Lee, Yong-Jin Ahn, Minyoung Kim, and Gi-Ja Lee
- Subjects
paper ,three-dimensional cell culture ,hydrogen sulfide ,live cancer cells ,colorimetric sensing paper ,paper-integrated analytical device ,Biochemistry ,QD415-436 - Abstract
In this study, a paper-integrated analytical device that combined a paper-based colorimetric assay with a paper-based cell culture platform was developed for the in situ detection of hydrogen sulfide (H2S) in three-dimensional (3D)-cultured, live prostate cancer cells. Two kinds of paper substrates were fabricated using a simple wax-printing methodology to form the cell culture and detection zones, respectively. LNCaP cells were seeded directly on the paper substrate and grown in the paper-integrated analytical device. The cell viability and H2S production of LNCaP cells were assessed using a simple water-soluble tetrazolium salt colorimetric assay and H2S-sensing paper, respectively. The H2S-sensing paper showed good sensitivity (sensitivity: 6.12 blue channel intensity/μM H2S, R2 = 0.994) and a limit of quantification of 1.08 μM. As a result, we successfully measured changes in endogenous H2S production in 3D-cultured, live LNCaP cells within the paper-integrated analytical device while varying the duration of incubation and substrate concentration (L-cysteine). This paper-integrated analytical device can provide a simple and effective method to investigate H2S signaling pathways and drug screening in a 3D culture model.
- Published
- 2022
- Full Text
- View/download PDF
27. A Novel Truncated DNAzyme Modified Paper Analytical Device for Point-of-Care Test of Copper Ions in Natural Waters
- Author
-
Jiayi Wu, Ming Wang, Huanhuan Hong, Jianyuan Lin, Ning Gan, and Wenchao Bi
- Subjects
paper-based device ,mobile phone ,DNAzyme ,Cu(II)-catalyzed azide-alkyne cycloaddition ,copper detection ,natural waters ,Biochemistry ,QD415-436 - Abstract
On-site determination of trace copper ions in natural waters is of great significance to environmental monitoring, and how to develop accurate and specific point-of-care test methods is one critical issue. In the study, a paper-based analytical device (PAD) being modified with a new truncated DNAzyme (CLICK-T, which was derived from a reported DNAzyme-CLICK-17) was developed for Cu ions detection. The detection mechanism was based on Cu(II)-catalyzed azide-alkyne cycloaddition (Cu(II)AAC) reaction. It can directly conduct on-site analysis of Cu(II) ions based on fluorescent signals detected using a mobile phone. In the assay, the CLICK-T was firstly modified on the PADs. Then, water samples containing Cu ions mixed with 3-azido-7-hydroxycoumarin and 3-butyn-1-ol were instantly dripped on PADs and incubated for 20 min. Finally, the PADs were excited at 365 nm and emitted fluorescence which could be analyzed on site using smart phones. The Cu(II) concentration could be quantified through RGB analysis with the aid of iPhone APP software. The limit of detection is 0.1 µM by the naked eye due to the fact that CLICK-T exhibited a good catalytic effect on Cu(II)AAC. The Cu(II) concentration could also be directly detected without using reductant, such as ascorbic acid, which is prone to be oxidized in air. This simplifies the PDA detection process improves its efficiency. The PAD is convenient for the on-site analysis of Cu ions in natural waters.
- Published
- 2022
- Full Text
- View/download PDF
28. Paper-Based Vapor Detection of Formaldehyde: Colorimetric Sensing with High Sensitivity
- Author
-
Chenglong Liao, Miao Zhang, Nan Gao, Qingyun Tian, Jiangfan Shi, Shuai Chen, Chuanyi Wang, and Ling Zang
- Subjects
vapor detection ,formaldehyde ,colorimetric ,paper-based sensor ,hydroxylamine ,Biochemistry ,QD415-436 - Abstract
We report on a novel colorimetric sensor system for highly sensitive detection of formaldehyde (FA) in the gas phase. The sensor is constructed with paper towel as a substrate coated with the sulfuric acid salt of hydroxylamine ((NH2OH)2·H2SO4) together with two pH indicators, bromophenol blue and thymol blue. Upon exposure to FA, the hydroxylamine will react with the absorbed FA to form a Schiff base (H2C=N-OH), thus releasing a stoichiometric amount of sulfuric acid, which in turn induces a color change of the pH indicator. Such a color change was significantly enriched by incorporating two pH indicators in the system. With the optimized molar ratio of the two pH indicators, the color change (from brown to yellow, and to red) could become so dramatic as to be visible to the eye depending on the concentration of FA. In particular, under 80 ppb of FA (the air quality threshold set by WHO) the color of the sensor substrate changes from brown to yellow, which can even be envisioned clearly by the naked eyes. By using a color reader, the observed color change can be measured quantitatively as a function of the vapor concentration of FA, which produces a linear relationship as fitted with the data points. This helps estimate the limit of detection (LOD), to be 10 ppb under an exposure time of 10 min, which is much lower than the air quality threshold set by WHO. The reported sensor also demonstrates high selectivity towards FA with no color change observed when exposed to other common chemicals, including solvents and volatile organic compounds. With its high sensitivity and selectivity, the proposed paper-based colorimetric sensor thus developed can potentially be employed as a low-cost and disposable detection kit that may find broad application in detecting FA in indoor air and many other environments.
- Published
- 2021
- Full Text
- View/download PDF
29. Fabrication of an All-Solid-State Ammonium Paper Electrode Using a Graphite-Polyvinyl Butyral Transducer Layer
- Author
-
Irena Ivanišević, Stjepan Milardović, Antonia Ressler, and Petar Kassal
- Subjects
ammonium ,solid contact ion-selective electrode ,paper-based sensor ,membrane ,potentiometric sensor ,Biochemistry ,QD415-436 - Abstract
A planar solid-state ammonium-selective electrode, employing a composite mediator layer of graphite particles embedded in a polyvinyl butyral matrix on top of an inkjet-printed silver electrode, is presented in this paper. The effect of graphite powder mass fraction on the magnitude of the potentiometric response of the sensor was systematically verified using a batch-mode and a flow injection measurement setup. Under steady-state conditions, the paper electrode provided a Nernstian response of 57.30 mV/pNH4 over the concentration range of 10−5 M to 10−1 M with a detection limit of 4.8 × 10−6 M, while the analytical performance of the array in flow mode showed a narrower linear range (10−4 M to 10−1 M; 60.91 mV/pNH4 slope) with a LOD value of 5.6 × 10−5 M. The experimental results indicate that the prepared electrode exhibited high stability and fast response to different molar concentrations of ammonium chloride solutions. The pH-response of the paper NH4-ISE was also investigated, and the sensor remained stable in the pH range of 2.5–8.5. The potentiometric sensor presented here is simple, lightweight and inexpensive, with a potential application for in-situ analysis of environmental water samples.
- Published
- 2021
- Full Text
- View/download PDF
30. Paper-Based Device for Sweat Chloride Testing Based on the Photochemical Response of Silver Halide Nanocrystals
- Author
-
Tatiana G. Choleva, Christina Matiaki, Afroditi Sfakianaki, Athanasios G. Vlessidis, and Dimosthenis L. Giokas
- Subjects
sweat testing ,cystic fibrosis ,paper-based devices ,silver halides ,photoreduction ,point-of-care diagnostics ,Biochemistry ,QD415-436 - Abstract
A new method for the determination of chloride anions in sweat is described. The novelty of the method relies on the different photochemical response of silver ions and silver chloride crystals when exposed to UV light. Silver ions undergo an intense colorimetric transition from colorless to dark grey-brown due to the formation of nanosized Ag while AgCl exhibits a less intense color change from white to slightly grey. The analytical signal is obtained as mean grey value of color intensity on the paper surface and is expressed as the absolute difference between the signal of the blank (i.e., in absence of chloride) and the sample (i.e., in the presence of chloride). The method is simple to perform (addition of sample, incubation in the absence of light, irradiation, and offline measurement in a flatbed scanner), does not require any special signal processing steps (the color intensity is directly measured from a constant window on the paper surface without any imager processing) and is performed with minimum sample volume (2 μL). The method operates within a large chloride concentration range (10–140 mM) with good detection limits (2.7 mM chloride), satisfactory recoveries (95.2–108.7%), and reproducibility (
- Published
- 2021
- Full Text
- View/download PDF
31. Disposable Microfluidic Paper-Based Device for On-Site Quantification of Urinary Creatinine
- Author
-
Maria M. P. Melo, Ana Machado, António O. S. S. Rangel, and Raquel B. R. Mesquita
- Subjects
µPAD ,creatinine determination ,urine samples ,Jaffe reaction ,real-time analysis ,Biochemistry ,QD415-436 - Abstract
In this work, a new microfluidic paper-based analytical device (µPAD) was developed for on-hand creatinine quantification in urine samples. When compared to conventional methods, this innovative paper device is more accessible and portable, it provides low-cost analysis (cost of consumables of 40 cents), and it is applicable to non-invasive biological fluids. Furthermore, the paper-based approach is used within an environmentally friendly assembly with no need for wax printing and small amounts of reagents resulting in low waste production and easy disposal by incineration. Its assembly method includes cutting paper discs arranged into several reading units within a plastic pouch, enabling effective creatinine quantification with accuracy based on a vertical flow approach. The method is based on the colourimetric reaction between creatinine and alkaline picric acid, where the solution colour changes from yellow to orange/red. Under optimal conditions, the developed method allowed creatinine quantification in the dynamic range of 2.20–35.0 mg/dL, with a limit of detection (LOD) of 0.66 mg/dL and a limit of quantification (LOQ) of 2.20 mg/dL. The colour intensity developed was processed in ImageJ software, based on digital image scanning, performed in 20 min (up to 4 h) after the sample insertion. The device is stable for up to one week when stored in a vacuum at 4 °C. The method was validated by comparing the results with a batch-wise procedure, where there were no statistically significant differences between both methods.
- Published
- 2023
- Full Text
- View/download PDF
32. Plastic-free chitosan and cellulose binder providing dry and wet strength to paper and nonwoven
- Author
-
Maria Wennman, Mårten Hellberg, Anna J Svagan, and Mikael S Hedenqvist
- Subjects
Nonwoven ,Binder ,Polyelectrolyte complex ,Chitosan ,Biobased ,Biochemistry ,QD415-436 - Abstract
Chemically-bonded nonwoven is commonly used in single-use products, and are often composed of cellulose fibers with a fossil-based binder. To reduce the amount of plastic littering, we investigated a biobased and biodegradable binder consisting of polyelectrolyte complexes based on chitosan, carboxymethyl cellulose and citric acid. The binder significantly improved the mechanical properties of two different types of cellulosic fiber systems in both dry and wet states. The quality of the water used in the binder had a significant impact on the mechanical properties, especially in the dry state, indicating a beneficial effect by the presence of cations. It was shown that covalent bonds were formed during the low temperature drying, and that the amount of bonds increased with a high temperature curing. Electron microscopy and tensile data indicated that the binder acted as a joint between the fiber/fiber parts. The presented results enable a sustainable solution for the current plastic-based nonwoven industry.
- Published
- 2022
- Full Text
- View/download PDF
33. LFA: The Mysterious Paper-Based Biosensor: A Futuristic Overview
- Author
-
Saumitra Singh, Mohd. Rahil Hasan, Akshay Jain, Roberto Pilloton, and Jagriti Narang
- Subjects
LFA ,history ,parts ,types ,construction ,futuristic applications ,Biochemistry ,QD415-436 - Abstract
Lateral flow assay (LFA) is emerging as one of the most popular paper-based biosensors in the field of the diagnostic industry. LFA fills all the gaps between diagnosis and treatment as it provides beneficial qualities to users such as quick response, Point-of-care appeal, early detection, low cost, and effective and sensitive detections of various infectious diseases. These benefits increase LFA’s dependability for disease management because rapid and accurate disease diagnosis is a prerequisite for effective medication. Only 2% of overall healthcare expenditures, according to Roche Molecular Diagnostics, are spent on in vitro diagnostics, even though 60% of treatment choices are based on this data. To make LFA more innovative, futuristic plans have been outlined in many reports. Thus, this review reports on very knowledgeable literature discussing LFA and its development along with recent futuristic plans for LFA-based biosensors that cover all the novel features of the improvement of LFA. LFA might therefore pose a very significant economic success and have a significant influence on medical diagnosis.
- Published
- 2023
- Full Text
- View/download PDF
34. Screening of Antifungal Activity of Essential Oils in Controlling Biocontamination of Historical Papers in Archives
- Author
-
Ana Tomić, Olja Šovljanski, Višnja Nikolić, Lato Pezo, Milica Aćimović, Mirjana Cvetković, Jovana Stanojev, Nebojša Kuzmanović, and Siniša Markov
- Subjects
Microbiology (medical) ,paper biodegradation ,Infectious Diseases ,paper conservation ,fungal contamination ,essential oil application ,fungicide effect ,Pharmacology (medical) ,General Pharmacology, Toxicology and Pharmaceutics ,Biochemistry ,Microbiology ,fungicides - Abstract
The main challenge in controlling the microbiological contamination of historical paper is finding an adequate method that includes the use of cost-effective, harmless, and non-toxic biocides whose effectiveness is maintained over time and without adverse effects on cultural heritage and human health. Therefore, this study demonstrated the possibility of using a non-invasive method of historical paper conservation based on plant essential oils (EOs) application. Evaluation of antimicrobial effects of different EOs (lemongrass, oregano, rosemary, peppermint, and eucalyptus) was conducted against Cladosporium cladosporoides, Aspergillus fumigatus, and Penicillium chrysogenum, which are commonly found on archive papers. Using a mixture of oregano, lemongrass and peppermint in ratio 1:1:1, the lower minimal inhibition concentration (0.78%) and better efficiency during a vapour test at the highest tested distance (5.5 cm) compared with individual EOs was proven. At the final step, this EOs mixture was used in the in situ conservation of historical paper samples obtained from the Archives of Vojvodina. According to the SEM imaging, the applied EOs mixture demonstrates complete efficiency in the inhibition of fungi colonization of archive papers, since fungal growth was not observed on samples, unlike the control samples.
- Published
- 2023
35. Carbon Fiber Paper Sensor for Determination of Trimethoprim Antibiotic in Fish Samples
- Author
-
Álvaro Torrinha, Miguel Tavares, Vitória Dibo, Cristina Delerue-Matos, and Simone Morais
- Subjects
electrochemical sensor ,carbon paper ,trimethoprim ,electroanalysis ,fish ,environmental analysis ,Electrical and Electronic Engineering ,Biochemistry ,Instrumentation ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry - Abstract
The increase in anthropogenic pollution raises serious concerns regarding contamination of water bodies and aquatic species with potential implications on human health. Pharmaceutical compounds are a type of contaminants of emerging concern that are increasingly consumed and, thus, being frequently found in the aquatic environment. In this sense, an electrochemical sensor based on an unmodified and untreated carbon fiber paper (CPS—carbon paper sensor) was simply employed for the analysis of trimethoprim antibiotic in fish samples. First, the analytical conditions were thoroughly optimized in order for the CPS to achieve maximum performance in trimethoprim determination. Therefore, an electrolyte (0.1 M Britton–Robinson buffer) pH of 7 was selected and for square wave voltammetry parameters, optimum values of amplitude, frequency and step potential corresponded to 0.02 V, 50 Hz, and 0.015 V, respectively, whereas the deposition of analyte occurred at +0.7 V for 60 s. In these optimum conditions, the obtained liner range (0.05 to 2 µM), sensitivity (48.8 µA µM−1 cm−2), and LOD (0.065 µM) competes favorably with the commonly used GCE-based sensors or BDD electrodes that employ nanostructuration or are more expensive. The CPS was then applied for trimethoprim determination in fish samples after employing a solid phase extraction procedure based on QuEChERS salts, resulting in recoveries of 105.9 ± 1.8% by the standard addition method.
- Published
- 2023
- Full Text
- View/download PDF
36. An origami microfluidic paper device for on-site assessment of urine tampering. First use of Nessler's reagent for the colorimetric determination of creatinine
- Author
-
Giacomo Musile, Yvane Agard, Sara Pesavento, Elio F. De Palo, Romolo M. Dorizzi, and Federica Bortolotti
- Subjects
Urine adulteration ,Microfluidics ,Biochemistry ,paper-based microfluidics devices (µPADs) ,Creatinine ,Urine tampering ,Forensic toxicology ,Analytical Chemistry ,Lab-On-A-Chip Devices ,Environmental Chemistry ,Colorimetry ,Indicators and Reagents ,Spectroscopy - Abstract
The relevance of the problem of urine tampering is well-known in forensic toxicology, with sample dilution being the most used method to cheat toxicological controls. Among the criteria to assess urine integrity, the quantification of creatinine probably represents the most popular method. The present paper presents a simple and low-cost analytical device for on-site creatinine determination as first-line screening for urine dilution. The proposed microfluidic devices were designed as a three-dimensional origami pattern. The device included three colorimetric reactions based on picric acid (PA-based reagent), 3,5-dinitrobenzoic acid (DNBA-based reagent), and Nessler's reagent. The last one, to the best of our knowledge, has never been used before for creatinine determination. In order to assure the highest ease and economy of operation, the color detection and data processing were performed using a built-in smartphone camera and the associated software. The optimized device showed a detection limit of 0.02 g/L. The proposed method was used for the qualitative screening for urine dilution of 48 samples, showing a diagnostic sensitivity and specificity for PA-based, DNBA-based and Nessler's reagent of 83.3%-80.0%, 72.2%-70.0%, and 100.0%-93.3% respectively, versus reference enzymatic method adopting a cut-off of 0.2 g/L. In conclusion, the present preliminary study shows that the proposed device could be a useful tool for on-site screening for urine tampering at the time of sample collection for toxicological testing.
- Published
- 2023
37. Secondary School Students' Perception of Biochemistry Concepts by Using Word Association Test
- Author
-
Roncevic, Tamara N., Horvat, Saša A., Rodic, Dušica D., and Bogdanovic, Ivana Z.
- Abstract
A word association test was used to determine knowledge structures on biochemistry concepts of secondary school chemistry students, aged between 18-19 years. The basic biochemistry concepts related to the topic of Carbohydrates that take place in the International Baccalaureate Diploma Programme curriculum were determined as stimulus words: "Monosaccharides", "Glucose", "Cellular respiration", "Fructose", "Disaccharides", "Glycosidic bonds", "Polysaccharides", "Starch". Students were required to provide response words for each of the eight stimulus words within the pre-determined period of time. Analysis of data was done in order to find the stimulus words with the highest number of associations in students' knowledge structures and to calculate the relatedness coefficient between the stimulus words, in order to construct the relatedness networks that should model the students' knowledge structures. The results showed that students managed to relate most of the stimulus words with strong or medium strength links, however, "Cellular respiration" remained unconnected to other stimulus words in the students' knowledge structures. [For the full proceedings, see ED629086.]
- Published
- 2023
38. A Flexible Capacitive Paper-Based Pressure Sensor Fabricated Using 3D Printing
- Author
-
Wendan Jia, Qiang Zhang, Yongqiang Cheng, Jie Wang, Hulin Zhang, Shengbo Sang, and Jianlong Ji
- Subjects
AgNWs ,structured flexible pressure sensor ,capacitive sensor ,3D printing ,Biochemistry ,QD415-436 - Abstract
Flexible pressure sensors usually exhibit high sensitivity, excellent resolution, and can be mass-produced. Herein, a high-resolution, capacitive, paper-based, 3D-printed pressure sensor with a simple, low-cost preparation method is proposed. The sensor has a wide detection range (300–44,000 Pa), a short response time (
- Published
- 2022
- Full Text
- View/download PDF
39. Development of a Paper-Based Analytical Method for the Colorimetric Determination of Calcium in Saliva Samples
- Author
-
Maria Tarara, Paraskevas D. Tzanavaras, and George Z. Tsogas
- Subjects
Electrical and Electronic Engineering ,paper-based analytical devices ,colorimetric determination ,calcium ,methylthymol blue ,saliva samples ,Biochemistry ,Instrumentation ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry - Abstract
A novel, rapid, and facile method for the colorimetric determination of calcium using micro-analytical paper-based devices (μ-PADs) was developed. The proposed analytical method utilizes the color differences developing, after the addition of calcium, on the surface of the devices because of the complexation reaction of calcium with Methylthymol Blue (MTB) at room temperature, in alkaline pH. The devices were manufactured with chromatographic paper, using wax barriers, and the analytical protocol was easily implemented without the need of any experimental apparatus except for a simple imaging device. The user must regulate the pH, add the solutions on the paper, and measure the color intensity of the formed Ca(II)–MTB complex with a flatbed scanner. The experimental conditions for optimum color development, the possible interfering substances, and the reliability of the paper devices in different preserving conditions were optimized, with satisfactory results. The method exhibited acceptable detection limits (2.9 mg L−1) with sufficiently good precision, which varied from 4.2% (intra-day) to 6.4% (inter-day). Saliva samples from healthy volunteers were successfully analyzed, and the calcium levels were calculated in the range of 30.71 to 84.15 mg L−1.
- Published
- 2022
- Full Text
- View/download PDF
40. Supply And Installation Of Semi Automatic Biochemistry Analyser, Binocular Microscope, Cotton, Syringe 5cc, Whatmann No.1 Filter Paper, Cappillary Tube, Lancet, Test Tube 15x125 Mm, Tourniquet, Cover Slip, Esr Pipette (westegrens), Spirit Lamp (glass), Gl
- Subjects
Biochemistry ,Medical supplies -- Installation ,Technology installation instructions ,Business, international - Abstract
Tenders are invited for Supply and installation of Semi Automatic Biochemistry Analyser, Binocular microscope, Cotton, Syringe 5cc, Whatmann no.1 filter paper, Cappillary tube, Lancet, Test tube 15x125 mm, Tourniquet, Cover [...]
- Published
- 2023
41. The Role of Mathematics Learning in the Interdisciplinary Mathematics and Science (IMS) Project
- Author
-
Mathematics Education Research Group of Australasia (MERGA), Mulligan, Joanne, Tytler, Russell, Prain, Vaughan, White, Peta, Xu, Lihua, and Kirk, Melinda
- Abstract
While interdisciplinary approaches in the STEM subjects are widely advocated there are concerns that disciplinary learning can be compromised, especially in mathematics. The Interdisciplinary Mathematics and Science (IMS) project is a three-year longitudinal study in four Victorian primary schools that has developed a pedagogical approach to mathematics and science learning where data modelling and representation are common to each. Investigations include astronomy, ecology, chemistry, fast plant growth, force and motion, water use, heat and temperature, body height, light and microorganisms. The paper describes the role of mathematics in the IMS pedagogical model and design of learning sequences.
- Published
- 2022
42. Paper and thread as media for the frugal detection of urinary tract infections (UTIs)
- Author
-
Hardik Ramesh Singhal, Amrutha Hasandka, Ankita Ramchandran Singh, Naresh Kumar Mani, M. S. Giri Nandagopal, and Anusha Prabhu
- Subjects
Burden of disease ,Paper ,medicine.medical_specialty ,Thread (network protocol) ,Microfluidics ,Review ,Biochemistry ,Analytical Chemistry ,Lab-On-A-Chip Devices ,Health care ,medicine ,Humans ,Intensive care medicine ,Cellulose ,Menstrual Hygiene Products ,Urinary tract infection ,Modalities ,Bacteria ,business.industry ,Public health ,Fungi ,Electrochemical Techniques ,Thread ,Culture Media ,Detection ,Urinary Tract Infections ,Colorimetry ,business - Abstract
Urinary tract infections (UTIs) make up a significant proportion of the global burden of disease in vulnerable groups and tend to substantially impair the quality of life of those affected, making timely detection of UTIs a priority for public health. However, economic and societal barriers drastically reduce accessibility of traditional lab-based testing methods for critical patient groups in low-resource areas, negatively affecting their overall healthcare outcomes. As a result, cellulose-based materials such as paper and thread have garnered significant interest among researchers as substrates for so-called frugal analytical devices which leverage the material’s portability and adaptability for facile and reproducible diagnoses of UTIs. Although the field may be only in its infancy, strategies aimed at commercial penetration can appreciably increase access to more healthcare options for at-risk people. In this review, we catalogue recent advances in devices that use cellulose-based materials as the primary housing or medium for UTI detection and chart out trends in the field. We also explore different modalities employed for detection, with particular emphasis on their ability to be ported onto discreet casings such as sanitary products. Graphical abstract
- Published
- 2021
43. The Ability of a Bacterial Strain to Remove a Phenolic Structure as an Approach to Pulp and Paper Mill Wastewater Treatment: Optimization by Experimental Design
- Author
-
María Cristina Yeber and Tatiana Silva
- Subjects
Geography, Planning and Development ,phenolic compounds ,pulp and paper industry ,pollution control ,wastewater cleaning ,water sustainability ,Aquatic Science ,Biochemistry ,Water Science and Technology - Abstract
High-colored wastewater generated during the cellulose bleaching process causes the inhibition of biological activity when released into the environment. This study aimed to evaluate the bacterium’s capacity, identified as RGM2262, to degrade a complex phenolic structure such as lignin, which is found in high concentrations in the effluents generated during the production of cellulose, raw material for the manufacture of paper. To determine the values of the experimental variables that allow for a greater degradation of organic matter, an experimental model was carried out through experimental design. Thus, the experimental matrix was obtained with the variables pH 7 (−1) to 9 (+1) and a treatment time of 1 day (−1) to 5 days (+1). The results show that, at pH 8 and pH 9, both treatments—with bacteria in bio-films and without bio-films—were efficient. On the second day of treatment, 100% of the color and the phenolic structure were removed, with a similar rate constant, and at the same time, 80% COD and 70% of TOC, respectively.
- Published
- 2022
- Full Text
- View/download PDF
44. Gamification Using Labyrinths and Mazes to Learn Biomolecule's Nomenclature of Biochemistry in Chemistry Degree
- Author
-
Josep J. Centelles, Estefania Moreno, and Pedro R. de Atauri
- Abstract
Gamification is a very useful technique, that has been fully increasing in the last years. During the COVID-19 pandemic, our innovation teaching group sent to our students several games, that were used by them for self-studying. Considering that many numerical problems can be proposed in Biochemistry, rather than numerical games (sudoku, adding and subtracting number games, …) word games were preferred to learn biomolecule nomenclature. Among these word games, we adapted to Biochemistry: connecting dots, labyrinths, mazes, matching two sets, amidakuji, logic games, crossword puzzles, word search puzzles, knight's tour games or anagrams. In this work, we present several games related to labyrinths and mazes. Connecting dot games were adapted to Biochemistry by using intermediate metabolite of a pathway instead of numbers to develop a picture when connecting the dots. Anyway, as pathways don't contain a big number of metabolites, no difficult pictures can be used. Thus, a labyrinth with questions and answers and letters connecting questions with answers can be better used. Correct answers can develop the letters of a biomolecule's name. Other kind of labyrinth can be those where the letters can be taken from the shortest route. Labyrinths can also be used to develop a word following the route in labyrinths and taking letters to get the word, as an anagram. Several examples are shown hereby, adapted for Biochemistry students of Chemistry degree. [For the full proceedings, see ED654100.]
- Published
- 2023
45. ACEs Are Wild: How Educators Can Positively Influence the 'Hand' Students Are Dealt
- Author
-
Amanda M. Butler
- Abstract
Failing test scores in reading proficiency have been a blemish on our nation's report card for decades as scores have remained static despite the readily-available information on language and literacy attainment, and the employment of research-based strategies in classrooms. While we continue our quest to efficiently bolster reading skills, a less obvious solution may have little to do with literacy and everything to do with neuroscience. Over 60% of youths have suffered from one or more adverse childhood experiences (ACEs), and children who experience adversity are more likely to struggle in school. Cortisol, a hormone released under stress, limits brain function and negatively impacts one's working memory, decision-making skills, and attention, all of which are required for reading proficiency. Researchers have proven that oxytocin, the "love hormone", reverses the effects of cortisol and is easily triggered in classroom settings via physical contact. By reversing the effects of cortisol, students will have the "mental real estate" to learn and retain the skills and knowledge necessary to become proficient readers. [For the full proceedings, see ED656038.]
- Published
- 2023
46. The Hybrid stylus : a multi-surface active stylus for interacting with and handwriting on paper, tabletop display or both
- Author
-
Klen Čopič Pucihar, Cuauhtli Campos, Matjaž Kljun, and Jakub Sandak
- Subjects
pen-paper user interfaces ,digitisation ,handwriting ,tablet computers ,tabletop computers ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Time ,Computers, Handheld ,Graphite ,Electrical and Electronic Engineering ,Instrumentation ,Software - Abstract
The distinct properties and affordances of paper provide benefits that enabled paper to maintain an important role in the digital age. This is so much so, that some pen–paper interaction has been imitated in the digital world with touchscreens and stylus pens. Because digital medium also provides several advantages not available to physical paper, there is a clear benefit to merge the two mediums. Despite the plethora of concepts, prototypes and systems to digitise handwritten information on paper, these systems require specially prepared paper, complex setups and software, which can be used solely in combination with paper, and, most importantly, do not support the concurrent precise interaction with both mediums (paper and touchscreen) using one pen only. In this paper, we present the design, fabrication and evaluation of theHybrid Stylus.TheHybrid Stylusis assembled with the infinity pencil tip (nib) made of graphite and a specially designed shielded tip holder that is attached to an active stylus. The stylus can be used for writing on a physical paper, while it still maintains all the features needed for tablet interaction. Moreover, the stylus also allows simultaneous digitisation of handwritten information on the paper when the paper is placed on the tablet screen. In order to evaluate the concept, we also add a user-friendly manual alignment of paper position on the underlying tablet computer The evaluation demonstrates that the system achieves almost perfect digitisation of strokes (98.6% of strokes were correctly registered with only 1.2% of ghost strokes) whilst maintaining excellent user experience of writing with a pencil on the paper.
- Published
- 2022
47. Flame retardant and antimicrobial paper coatings with rosemary oil and barium borate
- Author
-
URAL, ELİF and Çölük G., URAL E., Kandirmaz E. A.
- Subjects
Antimicrobial coating ,Temel Bilimler (SCI) ,MATERIALS SCIENCE, MULTIDISCIPLINARY ,Biochemistry ,MATERIALS SCIENCE ,Organik Kimya ,Kimya ,Flame retardant ,CHEMISTRY ,Biyokimya ,KİMYA, ORGANİK ,Materials Chemistry ,Biyoinorganik Kimya ,MALZEME BİLİMİ, ÇOKDİSİPLİNLİ ,Engineering, Computing & Technology (ENG) ,Bioinorganic Chemistry ,Paper coating ,Malzeme Kimyası ,Temel Bilimler ,Organic Chemistry ,Printability ,Mühendislik, Bilişim ve Teknoloji (ENG) ,CHEMISTRY, ORGANIC ,Fizik Bilimleri ,Natural Sciences (SCI) ,Physical Sciences ,Engineering and Technology ,Active packaging ,Mühendislik ve Teknoloji ,Natural Sciences ,Malzeme Bilimi - Abstract
© 2022, Publishing House of the Romanian Academy. All rights reserved.Adding an antimicrobial effect to the papers used in the cardboard packaging industry can extend the life of the packed product. Paper, due to its structure, has the property of being ignited quickly. Enhancing the properties of paper, the combination of antimicrobial protection, low flammability and good printability to the paper will expand its usage area in the packaging industry. In this study, barium borate was synthesized in order to impart low flammability to paper. Different combinations of rosemary oil and barium borate were mixed with binding starch in varying amounts, and formulations were prepared. With these mixtures, 80 g/m2 paper was coated using a laboratory-type paper coating machine. The antimicrobial properties of the paper were investigated by performing the disk diffusion antimicrobial test against E. coli and S. aureus bacteria. The Limiting Oxygen Index (LOI) test was performed to determine the low flammability of the paper. Color, gloss, contact angle and surface energy tests were performed for the printability properties of the paper. As a result, the coatings containing formulations of barium borate and rosemary oil, applied to the paper surface, succeeded in imparting antimicrobial and low flammability properties to the papers, while also improving the printability features.
- Published
- 2022
48. Evaluating ChatGPT as a Self-Learning Tool in Medical Biochemistry: A Performance Assessment in Undergraduate Medical University Examination
- Author
-
Krishna Mohan Surapaneni, Anusha Rajajagadeesan, Lakshmi Goudhaman, Shalini Lakshmanan, Saranya Sundaramoorthi, Dineshkumar Ravi, Kalaiselvi Rajendiran, and Porchelvan Swaminathan
- Abstract
The emergence of ChatGPT as one of the most advanced chatbots and its ability to generate diverse data has given room for numerous discussions worldwide regarding its utility, particularly in advancing medical education and research. This study seeks to assess the performance of ChatGPT in medical biochemistry to evaluate its potential as an effective self-learning tool for medical students. This evaluation was carried out using the university examination question papers of both parts 1 and 2 of medical biochemistry which comprised theory and multiple choice questions (MCQs) accounting for a total of 100 in each part. The questions were used to interact with ChatGPT, and three raters independently reviewed and scored the answers to prevent bias in scoring. We conducted the inter-item correlation matrix and the interclass correlation between raters 1, 2, and 3. For MCQs, symmetric measures in the form of kappa value (a measure of agreement) were performed between raters 1, 2, and 3. ChatGPT generated relevant and appropriate answers to all questions along with explanations for MCQs. ChatGPT has "passed" the medical biochemistry university examination with an average score of 117 out of 200 (58%) in both papers. In Paper 1, ChatGPT has secured 60 ± 2.29 and 57 ± 4.36 in Paper 2. The kappa value for all the cross-analysis of Rater 1, Rater 2, and Rater 3 scores in MCQ was 1.000. The evaluation of ChatGPT as a self-learning tool in medical biochemistry has yielded important insights. While it is encouraging that ChatGPT has demonstrated proficiency in this area, the overall score of 58% indicates that there is work to be done. To unlock its full potential as a self-learning tool, ChatGPT must focus on generating not only accurate but also comprehensive and contextually relevant content.
- Published
- 2024
- Full Text
- View/download PDF
49. An Introduction to Modelling through a Microbial Interaction Application
- Author
-
Fabiana Zama
- Abstract
This paper describes a teaching experiment in a Numerical Methods course for Master of Science students. The experiment uses scientific papers to develop modelling studies in the context of wine fermentation microbial interactions. The course involves theoretical and laboratory classes that focus on implementing numerical methods using Matlab for Initial Value Problems and Boundary Value Problems. The students are asked to formalise the mathematical model and build their own experiments using the information provided in the papers. Additionally, a parameter estimation experiment is organised, which involves generating synthetic data and computing noisy data to estimate the natural death rate of sensitive yeast. The results show that data noise significantly affects the parameter estimate and that scaling the data can help reduce the impact of measurement errors. The presented results can be used to investigate other possible assignments, such as how the evaluation of the Jacobian affects the estimation performance and compare different optimisation algorithms.
- Published
- 2024
- Full Text
- View/download PDF
50. An Electrochemical Sensor Based on Carbon Paper Modified with Graphite Powder for Sensitive Determination of Sunset Yellow and Tartrazine in Drinks
- Author
-
Aleksey Tarasov, Ekaterina Khamzina, Mariya Bukharinova, and Natalia Stozhko
- Subjects
Reproducibility of Results ,Electrochemical Techniques ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Carbon ,Analytical Chemistry ,Limit of Detection ,food colorants ,Sunset Yellow ,Tartrazine ,carbon paper ,carbon veil ,electrochemical sensor ,modified electrode ,graphite powder ,voltammetry ,soft and alcoholic drinks ,Graphite ,Electrical and Electronic Engineering ,Powders ,Instrumentation ,Azo Compounds ,Electrodes - Abstract
The paper describes the development of an electrochemical sensor to be used for the determination of synthetic food colorants such as Sunset Yellow FCF (SY) and Tartrazine (TZ). The sensor is a carbon paper (CP) electrode, manufactured by using hot lamination technology and volume modified with fine-grained graphite powder (GrP). The sensor (GrP/CP) was characterized by scanning electron microscopy, energy dispersive spectrometry, electrochemical impedance analysis, cyclic, linear sweep and differential pulse voltammetry. The mechanism of SY and TZ electrochemical oxidation on GrP/CP was studied. The developed sensor has good electron transfer characteristics and low electron resistance, high sensitivity and selectivity. Applying the differential pulse mode, linear dynamic ranges of 0.005–1.0 μM and 0.02–7.5 μM with limits of detection of 0.78 nM and 8.2 nM for SY and TZ, respectively, were obtained. The sensor was used to detect SY and TZ in non-alcoholic and alcoholic drinks. The results obtained from drink analysis prove good reproducibility (RSD ≤ 0.072) and accuracy (recovery 96–104%).
- Published
- 2022
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.