82,268 results
Search Results
2. Exploration of the Scientific Papers and Self-Assessment of Students Using the COVID-19 Case on Biochemistry Course
- Author
-
Anwar, Yunita Arian Sani and Muti'ah, Muti'ah
- Abstract
The coronavirus disease 2019 (COVID-19) pandemic is a case that can be used as a biochemistry learning resource in relation to the topic of viruses. Learning to use cases will be effective if students are assigned to produce reports, articles, or other scientific papers. Self-assessment can be used to assess the competencies that have been learnt in the writing process. This study aims to analyze the scientific papers and self-assessment of students using the COVID-19 pandemic case. It includes qualitative research with scientific paper and self-assessment questionnaire analyses. The research sample was chemistry education study program students (N = 57) following biochemistry course, out of a population of 87 students. The results show that the students have a good understanding of explaining COVID-19. Self-assessment analysis shows that 80% of the students responded positively to eight statements; those who gave positive responses to each questionnaire statement were able to produce scientific papers. Good self-assessment is in line with the ability of students to compile good scientific papers.
- Published
- 2021
- Full Text
- View/download PDF
3. 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
4. Exploration of the scientific papers and self-assessment of students using the COVID-19 case on biochemistry course.
- Author
-
Anwar YAS and Muti'ah M
- Subjects
- Education, Distance, Female, Humans, Indonesia epidemiology, Male, Pandemics, Publications, Research Report, SARS-CoV-2, Self-Assessment, Students, Surveys and Questionnaires, Young Adult, Biochemistry education, COVID-19 epidemiology, Curriculum
- Abstract
The coronavirus disease 2019 (COVID-19) pandemic is a case that can be used as a biochemistry learning resource in relation to the topic of viruses. Learning to use cases will be effective if students are assigned to produce reports, articles, or other scientific papers. Self-assessment can be used to assess the competencies that have been learnt in the writing process. This study aims to analyze the scientific papers and self-assessment of students using the COVID-19 pandemic case. It includes qualitative research with scientific paper and self-assessment questionnaire analyses. The research sample was chemistry education study program students (N = 57) following biochemistry course, out of a population of 87 students. The results show that the students have a good understanding of explaining COVID-19. Self-assessment analysis shows that 80% of the students responded positively to eight statements; those who gave positive responses to each questionnaire statement were able to produce scientific papers. Good self-assessment is in line with the ability of students to compile good scientific papers., (© 2020 International Union of Biochemistry and Molecular Biology.)
- Published
- 2021
- Full Text
- View/download PDF
5. 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
6. Zacharias Dische and the discovery of feedback inhibition: A landmark paper published in the forerunner of Biochimie.
- Author
-
Cornish-Bowden A
- Subjects
- Animals, History, 19th Century, History, 20th Century, Humans, Biochemistry history, Metabolism
- Abstract
Zacharias Dische's discovery of feedback inhibition in metabolism was one of the most important in the history of biochemistry. However, his paper was written and published under very difficult circumstances in wartime and passed almost completely unnoticed. It is almost never cited, and the discovery itself is usually attributed to later work of others. Here I provide a discussion of Dische's work, a translation of his paper into English, and a transcription of the original French version, which is almost unobtainable anywhere., (Copyright © 2020. Published by Elsevier B.V.)
- Published
- 2021
- Full Text
- View/download PDF
7. My 100th JBC paper.
- Author
-
Sancar A
- Subjects
- History, 20th Century, History, 21st Century, Humans, Periodicals as Topic history, Biochemistry history
- Abstract
Nobel laureate Aziz Sancar writes about his decades-long relationship with the Journal of Biological Chemistry. Since 1984, he has published 100 papers in JBC, including this "Reflections.", Competing Interests: Conflict of interest The author declares no conflict of interest with the contents of this article., (Copyright © 2020 The Author. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
8. Protein Science Best Paper awards to Tatsuya Niwa, Qingping Xu, and Matthew Biancalana.
- Subjects
- Humans, Portraits as Topic, Awards and Prizes, Biochemistry, Protein Biosynthesis, Protein Folding
- Published
- 2020
- Full Text
- View/download PDF
9. 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
10. 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
11. Proceedings of International Conference on Research in Education and Science (Antalya, Turkey, April 1-4, 2021). Volume 1
- Author
-
International Society for Technology, Education and Science (ISTES) Organization, Shelley, Mack, Chiang, I-Tsun, and Ozturk, O. Tayfur
- Abstract
"Proceedings of International Conference on Research in Education and Science" includes full papers presented at the International Conference on Research in Education and Science (ICRES) which took place on April 1-4, 2021 in Antalya, Turkey. The aim of the conference is to offer opportunities to share ideas, to discuss theoretical and practical issues and to connect with the leaders in the fields of education and science. The conference is organized annually by the International Society for Technology, Education, and Science (ISTES). The ICRES invites submissions which address the theory, research or applications in all disciplines of education and science. The ICRES is organized for: faculty members in all disciplines of education and science, graduate students, K-12 administrators, teachers, principals and all interested in education and science. After peer-reviewing process, all full papers are published in the Conference Proceedings. [Individual papers are indexed in ERIC.]
- Published
- 2021
12. Proceedings of International Conference on Research in Education and Science (Antalya, Turkey, April 1-4, 2021). Volume 1
- Author
-
International Society for Technology, Education and Science (ISTES) Organization, Shelley, Mack, Chiang, I-Tsun, and Ozturk, O. Tayfur
- Abstract
"Proceedings of International Conference on Research in Education and Science" includes full papers presented at the International Conference on Research in Education and Science (ICRES) which took place on April 1-4, 2021 in Antalya, Turkey. The aim of the conference is to offer opportunities to share ideas, to discuss theoretical and practical issues and to connect with the leaders in the fields of education and science. The conference is organized annually by the International Society for Technology, Education, and Science (ISTES). The ICRES invites submissions which address the theory, research or applications in all disciplines of education and science. The ICRES is organized for: faculty members in all disciplines of education and science, graduate students, K-12 administrators, teachers, principals and all interested in education and science. After peer-reviewing process, all full papers are published in the Conference Proceedings.
- Published
- 2021
13. 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
14. 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
15. Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology.
- Author
-
Baptista MS, Alves MJM, Arantes GM, Armelin HA, Augusto O, Baldini RL, Basseres DS, Bechara EJH, Bruni-Cardoso A, Chaimovich H, Colepicolo Neto P, Colli W, Cuccovia IM, Da-Silva AM, Di Mascio P, Farah SC, Ferreira C, Forti FL, Giordano RJ, Gomes SL, Gueiros Filho FJ, Hoch NC, Hotta CT, Labriola L, Lameu C, Machini MT, Malnic B, Marana SR, Medeiros MHG, Meotti FC, Miyamoto S, Oliveira CC, Souza-Pinto NC, Reis EM, Ronsein GE, Salinas RK, Schechtman D, Schreier S, Setubal JC, Sogayar MC, Souza GM, Terra WR, Truzzi DR, Ulrich H, Verjovski-Almeida S, Winck FV, Zingales B, and Kowaltowski AJ
- Subjects
- Brazil, Humans, Periodicals as Topic standards, Periodicals as Topic trends, Biochemistry, Molecular Biology, Periodicals as Topic statistics & numerical data, Publishing trends, Research
- Abstract
The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.
- Published
- 2019
- Full Text
- View/download PDF
16. 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
17. 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
18. 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
19. 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
20. The Herbert Tabor Best Paper Awards: Celebrating young authors who contribute top content to JBC.
- Author
-
Gierasch LM and DeMartino G
- Subjects
- Awards and Prizes, Biochemistry, Periodicals as Topic
- Published
- 2017
- Full Text
- View/download PDF
21. Editorial on PBZ's Ninetieth Year and Top 90 Papers in PBZ, 1927-2017.
- Author
-
Garland T Jr, Canfield AL, and Bronoel M
- Subjects
- Animals, Editorial Policies, History, 20th Century, History, 21st Century, Biochemistry history, Periodicals as Topic history, Physiology history, Publishing history, Zoology history
- Published
- 2017
- Full Text
- View/download PDF
22. 'Publish SCI Papers or No Degree': Practices of Chinese Doctoral Supervisors in Response to the Publication Pressure on Science Students
- Author
-
Li, Yongyan
- Abstract
Publishing English papers in journals listed in Science Citation Index (SCI) has become a requirement for degree conferment for doctoral science students at many universities in China. The publication requirement engenders high pressure for doctoral students and their supervisors and shapes the politics of the relationship between the two parties. This is illustrated in the present paper which reports a study conducted at a prestigious university in east China. Focusing on the case of a research group in biochemistry led by an expert writer (the supervisor), the study aimed to find out, from the supervisor's perspective, what revising papers for the students means to him, and what the students learn as a result of their papers being revised. It is shown that the students depend on the supervisor to meet the publication requirement, and the supervisor believes an average student cannot write a publishable paper. The paper discusses the disempowering effect of the publication requirement, and concludes that there is a role for a course on academic English writing, and that the focus on "publishing SCI papers or no degree" should be shifted at the policy level and long-term planning should go into the training of EAP-qualified language professionals.
- Published
- 2016
- Full Text
- View/download PDF
23. 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
24. 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
25. 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
26. 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
27. 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
28. Preparation of hydrophobic transparent paper via using polydimethylsiloxane as transparent agent
- Author
-
Feixiang Guan, Zhaoping Song, Furong Xin, Huili Wang, Dehai Yu, Guodong Li, and Wenxia Liu
- Subjects
Transparent paper ,Cellulose fiber paper ,Hydrophobicity ,Tetraethyl orthosilicate (TEOS) ,Polydimethylsiloxane ,Biochemistry ,QD415-436 - Abstract
Transparent paper with good hydrophobicity and flexibility was expected to act as an alternative substrate in fabrication of flexible electronics. However, conventional paper made of cellulose fibers was opaque and hydrophilic without undergoing special processing. Herein, cellulose fiber paper was treated by impregnating with hydrolyzed tetraethyl orthosilicate (TEOS) followed by coating with hydrophobic polydimethylsiloxane (PDMS) to prepare hydrophobic transparent paper. The results showed that silica nanoparticles produced by the TEOS hydrolysis improved the paper transparency to some extent, increased the paper thermal stability, but still remained the hydrophilicity of paper. After the paper was further coated with the PDMS and the PDMS was consolidated, the paper became clearly transparent and hydrophobic. The processed paper had a transmittance of more than 90% at 550 nm. The water contact angle of the paper reached about 110°. This work provided a new approach for the fabrication of hydrophobic transparent paper with conventional cellulose fiber paper.
- Published
- 2020
- Full Text
- View/download PDF
29. 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
30. 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
31. 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
32. 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
33. 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
34. 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
35. 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
36. 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
37. 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
38. 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
39. Use of biochemical miniaturized galleries, rRNA based lateral flow assay and Real Time PCR for Cronobacter spp. confirmation.
- Author
-
Tomas D, Fan M, Zhu S, and Klijn A
- Subjects
- Bacterial Typing Techniques, Biochemistry instrumentation, Cronobacter classification, Cronobacter isolation & purification, Data Accuracy, Food Contamination analysis, Food Microbiology methods, Humans, Infant, Infant, Newborn, Miniaturization, Paper, Phylogeny, Reagent Kits, Diagnostic, Reagent Strips analysis, Biochemistry methods, Cronobacter genetics, DNA, Bacterial genetics, Infant Formula microbiology, RNA, Ribosomal, 16S genetics, Real-Time Polymerase Chain Reaction methods
- Abstract
Identification of Cronobacter represent a major challenge for laboratories testing powdered infant formula (PIF). In the present study, two biochemical galleries and three molecular methods have been applied to confirm 276 Cronobacter spp. and non-Cronobacter isolates from different sources. Using the latest database of API 20 E and ID 32 E biochemical miniaturized kits, 53% and 78% of the isolates were identified respectively. From the available results, total accuracy for Cronobacter detection was in 97% (API 20 E) and 99% (ID 32 E). The three molecular methods were based on rRNA based lateral flow, Real Time PCR combined with either a hybridization or hydrolysis probe. For all three methods total accuracy was more than 99%. A pilot trial using Next Generation Sequencing (NGS) correctly identified 58 out of 66 isolates (88%) in DNA mixtures. The results indicate that the commercially available approaches such as ID 32 E, rRNA based lateral flow and Real Time PCR are all suitable for Cronobacter identification at the genus level. The NGS method may become a suitable alternative in the future, provided that the sequence database is improved., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
40. 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
41. 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
42. 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
43. 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
44. 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
45. Development of a High-Throughput Low-Cost Approach for Fabricating Fully Drawn Paper-Based Analytical Devices Using Commercial Writing Tools
- Author
-
Varvara Pagkali, Eleftheria Stavra, Dionysios Soulis, and Anastasios Economou
- Subjects
paper-based devices ,pen-on-paper ,plotting ,optical sensing ,electrochemical sensing ,marker pens ,Biochemistry ,QD415-436 - Abstract
This work reports the development and optimization of a rapid and low-cost pen-on-paper plotting approach for the fabrication of paper-based analytical devices (PADs) using commercial writing stationery. The desired fluidic patterns were drawn on the paper substrate with commercial marker pens using an inexpensive computer-controlled x–y plotter. For the fabrication of electrochemical PADs, electrodes were further deposited on the devices using a second x–y plotting step with commercial writing pencils. The effect of the fabrication parameters (type of paper, type of marker pen, type of pencil, plotting speed, number of passes, single- vs. double-sided plotting), the chemical resistance of the plotted devices to different solvents and the structural rigidity to multiple loading cycles were assessed. The analytical utility of these devices is demonstrated through application in optical sensing of total phenols using reflectance calorimetry and in electrochemical sensing of paracetamol and ascorbic acid. The proposed manufacturing approach is simple, low cost, flexible, rapid and fit-for-purpose and enables the fabrication of sub-“one-dollar” PADs with satisfactory mechanical and chemical resistance and good analytical performance.
- Published
- 2021
- Full Text
- View/download PDF
46. Retrieving structural information from scattering and attenuation data of transparent wood and (Nano)paper
- Author
-
Yoshiharu Nishiyama
- Subjects
Light scattering ,Transparent wood ,Nanocellulose ,Biochemistry ,QD415-436 - Abstract
Over the last 15 years, significant number of reports on transparent paper and transparent wood appeared in the literature. The light scattering data or transmission data are often given to describe the optical performance of the material. In addition, the data also contains structural information that can be further analyzed based on scattering theory. Some of the data are re-analyzed herein from structural analysis point of view related to the scattering phenomena. Quantitative analysis on the wavelength dependent optical density of nanopaper suggested that the scatterers are not isolated voids or microfibrils but rather large submicrometric and structural domains. Angular dependence of transparent wood scattering suggests the scattering units of a few micrometers such as cell wall are at the origin of high haze.
- Published
- 2021
- Full Text
- View/download PDF
47. 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
48. Evaluation of Photosensitive Paper Coatings as Detectors for Instrumentation-Free UV Photometric Analysis Based on Photography-Based Photometry
- Author
-
Tatiana G. Choleva, Afroditi Sfakianaki, Athanasios G. Vlessidis, and Dimosthenis L. Giokas
- Subjects
instrumentation-free assays ,photography-based photometry ,UV analysis ,optical detection ,photosensitive paper coatings ,Biochemistry ,QD415-436 - Abstract
Photography-based photometry is a technique developed to perform high throughput UV photometric analysis without instrumental detectors in resource-limited settings. Its principle relies on the illumination of a sample with UV irradiation and then capturing the transmitted irradiation on a photosensitive paper surface. Therefore, the photosensitive surface acts as a detector for the determination of the concentration of analytes in the sample. This work aims to investigate the optimum photosensitive paper coatings for capturing the transmitted UV irradiation. To this end, photosensitive coatings based on silver, iron, and dichromate salts were tested using three assays of pharmaceutical and biochemical interest. The results from both calibrations, using standard solutions and the application in real samples, show that photosensitive coatings based on iron salts provide the best results. Importantly, the detection limits and the linear range of the calibration curves were better than those obtained with standard photometry. Based on these findings, cyanotype green papers, are proposed as optimum detectors for photography-based photometry. This finding simplifies the operation of the technique enabling the fabrication of prototype readers for analytical assays performed in resource limited settings, point-of-need applications or in the field.
- Published
- 2021
- Full Text
- View/download PDF
49. Evaluating TiO2 Photocatalysis Performance in Microtubes on Paper Background by Smartphone: Principles and Application Examples
- Author
-
Xian Liu, Chengxiang Xu, Shiwei Xie, Lei Zhu, and Xun Wang
- Subjects
TiO2 photocatalysis ,smartphone ,paper and microtubes ,greyscale ,analysis method ,Biochemistry ,QD415-436 - Abstract
Titanium dioxide (TiO2) photocatalysis is a popular and promising technology in water treatment, but the performance evaluation usually depends on expensive equipment. In this study, using a smartphone for colorimetric detection, a self-invented method based on paper and microtubes (PMTs) is proposed to test the photocatalytic performance of TiO2. Firstly, the study has identified that PMTs achieved a correlation coefficient of above 0.9 between the greyscale values and concentrations during the physical process of different color dyes (i.e., rhodamine B (RhB), reactive yellow (RY), methylene blue (MB), and mixtures of the two or three dyes). The results indicate that when the principle of solution color follows the CMYK (Cyan, Magenta, Yellow, Black) color model, its photo color on white paper background conforms to the RGB (Red, Green, Blue) color model. Compared to the results obtained from the absorbance method, the PMTs method showed high reliabilities up to 99.36% on the monitoring of the photocatalytic process of the different dye solutions. Interestingly, the colorless solution of salicylic acid (SA) could also be analyzed by the PMTs after complexed with Fe(III) ion to develop a purple solution. These results suggest that the PMTs could be an alternative analysis method to evaluating physical and chemical reaction processes when the high-tech analysis equipment is unviable.
- Published
- 2021
- Full Text
- View/download PDF
50. UV-Responsive Screen-Printed Porous ZnO Nanostructures on Office Paper for Sustainable and Foldable Electronics
- Author
-
Sofia Henriques Ferreira, Inês Cunha, Joana Vaz Pinto, Joana Pereira Neto, Luís Pereira, Elvira Fortunato, and Rodrigo Martins
- Subjects
ZnO nanostructures ,porous ZnO ,paper substrates ,microwave synthesis ,UV sensing ,sustainable electronics ,Biochemistry ,QD415-436 - Abstract
The fabrication of low-cost, flexible, and recyclable electronic devices has been the focus of many research groups, particularly for integration in wearable technology and the Internet of Things (IoT). In this work, porous zinc oxide (ZnO) nanostructures are incorporated as a UV sensing material into the composition of a sustainable water-based screen-printable ink composed of carboxymethyl cellulose (CMC). The formulated ink is used to fabricate flexible and foldable UV sensors on ubiquitous office paper. The screen-printed CMC/ZnO UV sensors operate under low voltage (≤2 V) and reveal a stable response over several on/off cycles of UV light exposure. The devices reach a response current of 1.34 ± 0.15 mA and a rise and fall time of 8.2 ± 1.0 and 22.0 ± 2.3 s, respectively. The responsivity of the sensor is 432 ± 48 mA W−1, which is the highest value reported in the literature for ZnO-based UV sensors on paper substrates. The UV-responsive devices display impressive mechanical endurance under folding, showing a decrease in responsivity of only 21% after being folded 1000 times. Their low-voltage operation and extreme folding stability indicate a bright future for low-cost and sustainable flexible electronics, showing potential for low-power wearable applications and smart packaging.
- Published
- 2021
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.