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In this study, we designed three promising platforms based on metal–organic frameworks (MOFs) to develop paper-based analytical devices (PADs) for biosensing applications. PADs have become increasingly popular in field sensing in recent years due to their portability, low cost, simplicity, efficiency, fast detection capability, excellent sensitivity, and selectivity. In addition, MOFs are excellent choices for developing highly sensitive and selective sensors due their versatility for functionalizing, structural stability, and capability to adsorb and desorb specific molecules by reversible interactions. These materials also offer the possibility to modify their structure and properties, making them highly versatile and adaptable to different environments and sensing needs. In this research, we synthesized and characterized three different amino-functionalized MOFs: UiO-66-NH2 (Zr), MIL-125-NH2 (Ti), and MIL-101-NH2 (Fe). These MOFs were used to fabricate PADs capable of sensitive and portable monitoring of alkaline phosphatase (ALP) enzyme activity by laser-induced fluorescence (LIF). Overall, amino-derivated MOF platforms demonstrate significant potential for integration into biosensor PADs, offering key properties that enhance their performance and applicability in analytical chemistry and diagnostics.

In this study, we designed three promising platforms based on metal–organic frameworks (MOFs) to develop paper-based analytical devices (PADs) for biosensing applications. PADs have become increasingly popular in field sensing in recent years due to their portability, low cost, simplicity, efficiency, fast detection capability, excellent sensitivity, and selectivity. In addition, MOFs are excellent choices for developing highly sensitive and selective sensors due their versatility for functionalizing, structural stability, and capability to adsorb and desorb specific molecules by reversible interactions. These materials also offer the possibility to modify their structure and properties, making them highly versatile and adaptable to different environments and sensing needs. In this research, we synthesized and characterized three different amino-functionalized MOFs: UiO-66-NH2 (Zr), MIL-125-NH2 (Ti), and MIL-101-NH2 (Fe). These MOFs were used to fabricate PADs capable of sensitive and portable monitoring of alkaline phosphatase (ALP) enzyme activity by laser-induced fluorescence (LIF). Overall, amino-derivated MOF platforms demonstrate significant potential for integration into biosensor PADs, offering key properties that enhance their performance and applicability in analytical chemistry and diagnostics. [ABSTRACT FROM AUTHOR]

Low concentration of biomarkers (proteins, nucleic acids, metabolites) is a major concern in early disease diagnosis due to the very low concentration of these biomarkers at the early stage of any disease. This challenge can be addressed by preconcentrating the biomarkers to improve the sensitivity of the diagnostic device. This paper describes a novel method to preconcentrate the charged molecules on paper using greenly synthesized iron nanoparticles. The iron nanoparticles were synthesized by utilizing plant extract as stabilizing agent, which both minimizes the cost and protects the environment. Three different samples of the nanoparticles were prepared by changing the charge or attaching a functional group (amine) to the surface. The iron nanoparticles act as a charged nanoporous membrane when deposited on the paper pads inducing electrostatic forces around the membrane leading to the concentration of the charged analytes near the boundary of the membrane. Crystal violet was used as a surrogate for the charged biomolecule. We report ∼24-fold increase in the concentration of crystal violet dye within 120 seconds using the positively charged membrane and the 0.2 mM dye solution. The developed experimental set-up eliminates the need for external pumping device and complex fabrication processes making the proposed method cost-effective, environment-friendly, and simple to use.

Background noise due to nonspecific binding of biomolecules on the assay substrates is one of the most common challenges that limits the sensitivity of microarray-based immunoassays. Background signal intensity usually increases when complex biological fluids are used because they have a combination of molecules and vesicles that can adsorb onto substrate surfaces. Blocking strategies coupled with surface chemistries can reduce such nonspecific binding and improve assay sensitivity. In this paper, we conducted a systematic optimization of blocking strategies on a variety of commonly used substrates for protein measurement in complex biofluids. Four blocking strategies (BSA, non-fat milk, PEG, and a protein-free solution) coupled with four surface chemistries (3-glycidoxypropyltrimethoxysilane (GPS), poly-L-lysine (PLL), aminoalkylsilane (AAS), and nitrocellulose (NC)) were studied for their effect on background, microspot, and net signal intensities. We have also explored the effect that these blocking strategies have when proteins in complex samples (plasma, serum, cell culture media, and EV lysate) are measured. Irregular spot morphology could affect signal extraction using automated software. We found that the microspots with the best morphology were the ones printed on GPS glass surfaces for all immunoassays. On NC membrane, the protein-based blocking strategies yielded the highest net fluorescent intensity with the antigen contained in PBS, plasma, serum, and serum-free cell culture media. Differently, with EV lysate samples, Pierce™ protein-free blocker yielded the best net signal intensity on both GPS and NC surfaces. The choice of blocking strategies highly depends on the substrate. Moreover, the findings discovered in this study are not limited to microarray-based immunoassays but can provide insights for other assay formats. [ABSTRACT FROM AUTHOR]

Research into paper-based sensors or functional materials that can perform analytical functions with active recognition capabilities is rapidly expanding, and significant research effort has been made into the design and fabrication of bioactive paper at the biosensor level to detect potential health hazards. A key step in the fabrication of bioactive paper is the design of the experimental and operational procedures for the immobilization of biomolecules such as antibodies, enzymes, phages, cells, proteins, synthetic polymers and DNA aptamers on a suitably prepared paper membrane. The immobilization methods are concisely categorized into physical absorption, bioactive ink entrapment, bioaffinity attachment and covalent chemical bonding immobilization. Each method has individual immobilization characteristics. Although every biomolecule-paper combination has to be optimized before use, the bioactive ink entrapment method is the most commonly used approach owing to its general applicability and biocompatibility. Currently, there are four common applications of bioactive paper: (1) paper-based bioassay or paper-based analytical devices for sample conditioning; (2) counterfeiting and countertempering in the packaging and construction industries; (3) pathogen detection for food and water quality monitoring; and (4) deactivation of pathogenic bacteria using antimicrobial paper. This article reviews and compares the different biomolecule immobilization techniques and discusses current trends. Current, emerging and future applications of bioactive paper are also discussed. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Glass microfibers are commonly used as biomolecule adsorption media, as structural or disposable components of the optical biosensors. While any improvement in these components are appreciated, utilizing basic tools of traditional approaches may lead to original sensor opportunities as simple, functional designs that can be easily disseminated. Following this pursuit, surface modification of glass microfiber paper surface was performed by 3-aminopropyltriethoxysilane (APTES) and resulting improvement in the cell entrapment capacity could be observed visually, only after Gram staining. Gram staining offered rapid validation of enhanced binding on the glass surface. The same APTES-modified samples were also tested for binding of complementary DNA sequences and the results were less straightforward due to the necessity of DNA visualization by using a fluorescent stain, YOYO-1. Accordingly, when there were no surface modification, DNA and YOYO-1 adsorbed readily on the glass microfiber filter paper, and prolonged the interaction between DNA and YOYO-1. YOYO-1 adsorption on glass could be recognized from the color profile of YOYO-1 emission. This phenomenon can be used to examine suitability of APTES coverage on glass surfaces since YOYO-1 emission can be distinguished by its glass adsorbed versus DNA-bound forms. Aptness of surface coverage is vital to biosensor studies in the sense that it is preceding the forthcoming surface modifications and its precision is imperative for attaining the anticipated interaction kinetics of the surface-immobilized species. The proposed testing scheme offered in this study secures the work, which is aimed to be carried out utilizing such sensing systems and device components. [Copyright &y& Elsevier]

A new paper in the journal Development explores the role of chemokines in embryonic development. The study focuses on an atypical chemokine receptor called ACKR3, which is found in the placenta. The researchers found that ACKR3 prevents a chemokine called CXCL12 from entering the embryonic bloodstream, ensuring proper haematopoiesis in the embryo. Interfering with ACKR3 function led to impaired bone marrow haematopoiesis, compromised fetal growth, and impaired immune and inflammatory responses in offspring. The researchers plan to further investigate the impact of interfering with placental ACKR3 on animals as they develop into adulthood and explore potential connections to human ACKR3 polymorphisms. [Extracted from the article]

Abstract: A novel method for the fabrication of paper-based microfluidic diagnostic devices is reported; it consists of selectively hydrophobizing paper using cellulose reactive hydrophobization agents. The hydrophilic–hydrophobic contrast of patterns so created has excellent ability to control capillary penetration of aqueous liquids in paper channels. Incorporating this idea with digital ink jet printing techniques, a new fabrication method of paper-based microfluidic devices is established. Ink jet printing can deliver biomolecules and indicator reagents with precision into the microfluidic patterns to form bio-chemical sensing zones within the device. This method thus allows the complete sensor, i.e. channel patterns and the detecting chemistries, to be fabricated only by two printing steps. This fabrication method can be scaled up and adapted to use high speed, high volume and low cost commercial printing technology. Sensors can be fabricated for specific tests, or they can be made as general devices to perform on-demand quantitative analytical tasks by incorporating the required detection chemistries for the required tasks. [Copyright &y& Elsevier]

Abstract Paper-based biosensors are promising for low-cost diagnostics. However, its widespread use has been hampered due to a lack of sensitive detection methods that can be easily implemented on paper substrates. On the other hand, single-walled carbon nanotubes (SWNTs) -based chemiresistive biosensors are gaining popularity as label-free, highly sensitive biosensors. However, traditional SWNT-based chemiresistors need to be more affordable for use in resource-limited settings. In this study, we report fabrication, optimization and analytical characterization of a chemiresistive biosensor on paper for label-free immunosensing. We synthesized a water-based ink using pyrene carboxylic acid (PCA) through non-covalent π-π stacking interaction between PCA and SWNTs. The PCA/SWNTs ink concentration can reach ~4 mg mL−1 and was stable at room temperature for one month. We introduced a combination of wax printing and vacuum filtration to fabricate the hydrophilic channels and the well-defined PCA/SWNTs ink deposition on paper in a facile manner requiring no additional masks or stencils. Specific antibodies were then functionalized on the PCA/SWNTs. Quantitative and selective detection of human serum albumin (HSA) is demonstrated with a limit of detection (LOD) of 1 pM. This low LOD is attributed to the porous structure of the paper surface, which can accommodate more SWNTs. Furthermore, the hydroxyl group-containing cellulose fibers help connect the SWNTs into an electrical network. The paper-based chemiresistive biosensor proposed here is easy to fabricate, and designed for rapid, sensitive and selective detection of HSA. This work provides a potential platform for automated, disposable paper-based biosensors with multiplexed detection capability and microfluidic controls. Highlights • Low-cost, label-free SWNTs-based chemiresistive biosensor on paper is reported. • Simple, fast, stencil-free wax printing and vacuum filtration used for fabrication. • High concentration, stable, water-based SWNTs ink defines sensing channel. • Bioreceptor immobilized covalently on SWNTs by zero-length crosslinking chemistry. • Highly sensitive, selective, label-free human serum albumin detection demonstrated. [ABSTRACT FROM AUTHOR]

• A selective paper-based antibody-free COVID-19 assay. • The enzymatic activity of the virus-related 3CL protease is applied for detection. • All our tests were validated against PCR tests displaying similar selectivity and sensitivity. • Our sensor displays an ultrafast detection turnover of ca. 1 min. • No instruments are required to perform the simple colorimetric diagnosis. COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 has led to high mortality worldwide, with social and financial effects expected to persist for years to come. Since asymptomatic individuals cause a large portion of transmission, actions taken to curb the COVID-19 pandemic mostly rely on procedures aimed at detecting viral-related molecules in infected carriers. Currently, leading available detection methods fall short in reliability or point-of-care mass screening applicability. Here, we present an unprecedented antibody-free smart pH paper-based seconds-long detection platform against the virus-related enzyme 3CLpro as a saliva biomarker of SARS-CoV-2 infection. The selective proteolytic activity of 3CLpro is directly detected from native saliva using a peptide substrate-embedded pH-paper platform. 3CLpro presence in infected individuals leads to an ultrafast pH-drop in the paper matrix, thus leading to a sharp color change as direct means of detection. Ultrafast detection, simplicity, no requirement of surface chemistry by sensitive biomolecules, long-term stability, and point-of-care compatibility for COVID-19 mass screening were demonstrated. Forty-two subjects were tested, exhibiting highly sensitive and specific detection of SARS-CoV-2 infection. Finally, we foresee that this universal approach could be implemented for the multiplexed detection of other viral infections by detecting specific viral proteases. Importantly, since our approach does not require immune-specific antibodies for specific detection, the overall platform is extremely cost-efficient, less than 2 USD cents per assay, and suitable for the worldwide mass screening of viral infections, particularly in remote and developing world locations. Moreover, we propose an extremely easy-to-use and produce practical test strip design. [ABSTRACT FROM AUTHOR]

Paper has been used to engineer many types of bio-diagnostics. A major issue to most paper-based bio-diagnostics is the biomolecule instability causing the short shelf-life of the diagnostics. Commercial papers contain various polymeric additives. Polyamidoamine-epichlorohydrin (PAE), a polyelectrolyte typically used as wet-strength agent, is commonly used in filter papers and paper towels, which are often used as substrate in bioactive paper. However, the effect of cellulose or polymeric additives on antibody bioactivity is unknown. This limits paper optimization for diagnostic applications. In this study, model papers were made with and without PAE addition. IgM Anti-A blood typing antibody was physisorbed and dried on paper, aged for up to 9 weeks at different relative humidity (RH) conditions and the antibody activity was measured. The antibody bioactivity was represented as blood typing efficiency measured by image analysis. The surface chemical composition was measured using X-ray photoelectron spectroscopy (XPS). Antibody bioactivity loss was promoted by elevated RH, corresponding to increased paper water content. PAE significantly reduces the paper water content under ambient environment. Antibody bioactivity is higher on paper made with PAE under the high humidity conditions (57.6%–84.3% RH). However, under conditions of humidity saturation (100%RH), PAE shows little effect on reducing paper water content nor on protecting antibody bioactivity. These results demonstrate the water content of paper to be associated with antibody bioactivity loss. [ABSTRACT FROM AUTHOR]

Abstract: Paper-based biosensors represent a disruptive technology by providing instantaneous and low-cost diagnostics for health and environmental applications. The lack of sensitivity can be an obstacle for this technology to compete with traditional analytical instrumentations. Aiming to improve the sensitivity of a paper-based colorimetric biosensor, we have applied colloids engineering in combination with filtration to lower the paper substrate backgrounds and optimize the immobilization of bio-molecules on paper. A model system consisting of an enzyme, alkaline phosphatase (ALP), and an inorganic colloid, calcium carbonate (CC), flocculated by a cationic dimethylamino-ethyl-methacrylate polyacrylamide (CPAM), demonstrated that the optimized CC flocs are best for enhancing the detecting sensitivity of ALP. The CC floc structure on paper was optimized by modulating its structure in suspension. Subsequently, the filtration process and the wicking ability of paper enabled to freeze the deposited CC structure inherited from the suspension. The incorporation of biomolecules into the CC before immobilizing on paper through filtration provided not only a better microenvironment, but also a higher surface density of immobilized biomolecules. The ALP detection limit of 117fmol per zone (5mm circle) in the current study was fifty times lower than that of the common soaking method for biomolecule immobilization. The minimum amount of biomolecules per unit substrate area required for detection was lowered by over an order of magnitude, compared with spotting methods (i.e. inkjet printing). The improvement was also demonstrated by the steepest slope of standard curve, the lowest background, and the highest activity of the bioactive paper probed with the diluted BCIP/NBT liquid substrates. [Copyright &y& Elsevier]

[Display omitted] • A universal 3D CFP-MXene-MoS 2 (CMM) electrochemical interface was designed. • The flexible CMM interface permitted local enrichment of biomolecules. • The CMM interface realized the aM level microRNA detection. • The practicality of CMM interface towards biomolecules monitoring was validated. Flexible sensing technology has received widespread attention in the monitoring of human physiological indicators. Thus, it is of great significance to develop a universal flexible sensing interface for early diagnosis of multi-level biomarkers. Herein, we reported a multifunctional 3D carbon fiber paper (CFP)-MXene-MoS 2 (CMM) sensing interface, which provided a flexible electrochemical biosensing platform for the ultrasensitive detection of multiple bioanalysis in biofluids. Notably, the CMM electrochemical interface was comprised of staggered carbon fibers on which the organ-like MXene-MoS 2 heterostructure covered with MoS 2 nanosheet arrays was uniformly allocated, permitting local enrichment of biomolecules for enhanced biomolecular capture efficiency, laying a solid foundation for the ultrasensitive detection of multiple biomolecules. In proof-of-concept experiments, we validated that the flexible CMM interface could be applied for ultrasensitive analyzing of quite a few biomolecules like ascorbic acid (AA), uric acid (UA), dopamine (DA) and microRNA (miRNA), with charming sensitivity and reproducibility. It was worth mentioned that an ultra-high sensitivity of 3.16 aM was acquired towards detecting microRNA. Under optimal parameters, the designed electrochemical interface worked well in complex biofluids such as human serum and urine samples. Overall, this flexible and disposable CMM interface with ultrahigh sensitivity provided insights for a more portable, accessible and valuable approach for monitoring biomolecules in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Required metrological tools, such as higher order reference measurements procedures, pure substance and matrix certified reference materials, are established for small well defined molecules. Difficulties still remain in the provision of SI traceable standards in the area of larger biomolecules such as peptides/proteins. The provision of Primary Calibration Reference Services has been identified as a core technical competency for National Measurement Institutes (NMIs). A concept has been elaborated by the Focus Group I on peptide/protein purity for the strategic planning of ongoing Key Comparisons of the Protein Analysis Working Group (PAWG) within the Comité Consultatif pour la Quantité de Matière (CCQM). The assignment of the mass fraction content of high purity peptide/protein materials will be the subject of the CCQM-K115/P55.2 comparison series to directly support NMI services and certified reference materials currently being provided by NMIs. [ABSTRACT FROM AUTHOR]

In the pursuit of point-of-care systems that present high sensitivity and fast turnaround time, lateral flow is considered a remarkable promising class of in vitro diagnostics, and popularized by the pregnancy tests. A variety of lateral flow tests have emerged able to provide cardiac panels in emergency conditions, infectious disease screening, drug abuse, among others. However, most commercial tests only provide qualitative results, limiting their applicability for quantification thresholds of most biomarkers. In this paper, we propose a novel detection architecture for quantification of biomolecules labeled with magnetic nanoparticles employing two spin valve sensors. The main goal of this paper is to demonstrate that this architecture can detect and monitor MNPs flowing in a LFT strip for detection and quantification of different solutions varying in MNP concentration. In addition, we present preliminary analytical results that support our strategy for achieving biomolecular quantification using the proposed solution. [ABSTRACT FROM AUTHOR]

Membrane-based affinity chromatography has been extensively investigated for biomolecule purification and immunoadsorption. However, recently developed composite membranes have been found to be limited in their liquid flow rates. A chitosan/cellulose composite membrane is reported here, providing a large liquid flow rate through the membrane and good mechanical properties. This new membrane was prepared by coating a 0.5% chitosan solution containing 1% acetic acid and 15% polyethylene glycol (PEG) onto coarse filter paper. The flux of water through the membrane reached 8.9 ml/(min cm2) at a pressure drop of 5 psi. The adsorption of human IgG on the immobilized protein A composite membrane was further investigated under both equilibrium and dynamic conditions. The equilibrium adsorption did not follow the Langmuir model, but fitted the Freundlich–Langmuir composite equation nicely. A maximum equilibrium binding capacity of 33.20 mg/cm3 membrane and dissociate constant of 8.60 mg/ml were found. Dynamic binding capacity of 14.75 mg/cm3 membrane was obtained. Sample loading flow rates did not influence the dynamic binding capacity of IgG from human serum. However, increasing sample recirculation time increased the dynamic binding capacity of IgG from human serum by 60% over 40 min, compared with the operation without recirculation. Low non-specific binding was observed on both the protein A coupled and uncoupled chitosan/cellulose composite membranes. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) showed that the purified IgG from the human serum offered higher purity than the commercial IgG product. The results in this study indicate that the affinity chitosan/cellulose membrane has a great potential in fast purification of biomolecules. [Copyright &y& Elsevier]

The dynamic monitoring of biomolecules that are part of cell membranes generally constitutes a challenge. Electrochemiluminescence (ECL) biosensor assemblies provide clear advantages concerning microscopic imaging. Therefore, this paper proposes and analyzes a quantum dots-based biosensor assembly. Thus, particular attention is granted to biomolecules that are part of cell membranes. Additionally, this paper describes and analyzes a quantum dots-based biosensor assembly, which is used to implement a fully functional color ECL visualization system that allows for cellular and biomolecular structures to be accurately visualized. The related nano-emitter allows the implementation of real-time bioimaging scenarios. Consequently, the proposed approach is thoroughly evaluated relative to the time-dependent evolution of biomolecules. It has been demonstrated that traditionally problematic structures, like the biomolecules that are part of cell membranes, can be studied and monitored relative to their time-dependent dynamic evolution using the proposed solution. The reported research process has been conducted in the realm of cooperation with a specialized biomedical engineering company, and the described results are expected to substantially support a better understanding of the biomolecules' time-dependent dynamic evolution. [ABSTRACT FROM AUTHOR]

Hygiene assessment in industrial and clinical environments is crucial in the prevention of health risks. Current technologies for routine cleanliness evaluation rely on the detection of specific biomolecules, thus requiring more than one test for broad-range screening. Herein, the modulation of the catalytic activity of gold nanoparticles (AuNPs) by biomacromolecules was employed to develop a nanoplasmonic platform for general hygiene screening. AuNPs were immobilized on cellulose paper by simple adsorption. When ferricyanide was dispensed onto the paper, the AuNPs catalysed the ferricyanide's dissociation, releasing free cyanide ions that dissolved them. The AuNP dissolution produced an intense colour shift detectable with the naked eye. When biomacromolecules (e.g., proteins and polysaccharides) were present, they spontaneously attached to AuNPs, forming a biomolecular corona (biocorona), reducing their catalytic activity until complete suppression when the NPs were fully covered by molecules. The concentration-dependent decrease in the catalytic activity was here used to quantify biomacromolecules and complex samples such as milk, eggs, soy sauce and yeast extract (in 20 min), with detection limits comparable to those of standard methods, i.e., 0.25 µg mL−1 for albumin. This nano-enabled technology may be applied as a broad-range (unspecific) alert system for inexpensive cleanliness evaluation, with potential applications in sensitive sectors including productive industries and hospitals. [ABSTRACT FROM AUTHOR]

Portable devices featured with fast analysis and affordable methodologies for clinical diagnostics have stimulated the rapid development of point-of-care (POC) technologies, potentially lowering the mortality rate. Herein, we demonstrated a portable, robust, and user-friendly intelligent metal-organic frameworks (MOFs) paper device, called smartphone-assisted biomimetic MOFs nanoreactor colorimetric paper (SBMCP), for on-demand POC detection of endogenous biomolecules. The concept of this paper platform was analogous to the intracellular cascades signal transduction, wherein the single/multiple enzymes components trapped within a ZIF-8 exoskeleton allowed the sensitive and selective recognition of target analyte via the accessible micropores network of ZIF-8, and then transferred the recognition event to a visual color signal based on the cascade reaction. Meanwhile, the ZIF-8 exoskeleton also endowed the enzymes with significantly elevated stability. As a result, this robust and portable SBMCP sensor enabled the on-site analysis of different important disease-related biomolecules through modulating the enzyme cascades, combining with a custom-designed smartphone application for signal readout. In the SBMCP assay, no sophisticated instruments or professional skill of the user was required, only 5 μL sample volume was needed, and the whole analysis process could be achieved within a portable MOFs paper and pervasive smartphone, endowing this new assay with the merits of low-cost, time-saving and easy-to-use. We demonstrated this SBMCP sensor was capable of real-time colorimetric detection of glucose and uric acid in diabetes and gout events. It is believed that this portable biosensor platform proposed herein potentially represents promising alternatives for POC diagnosis, especially applicable in developing world and resource-limited settings. Image 1 • A smartphone-assisted biomimetic MOFs paper device for POC detection was reported. • The stability of paper biosensor was significantly elevated by armour-like ZIF-8 exoskeleton. • On-demand detection for different biomarkers were achieved by modulating the enzyme cascades. • Real-time and on-site POC monitoring of glucose and uric acid in diabetes and gout events was achieved. [ABSTRACT FROM AUTHOR]

Single-atom nanozymes, with their atomically dispersed metal active sites, distinctive atom utilization rate, and tunable electronic structure, demonstrate great promise in the field of sensing analysis. This paper reviews the latest research progress on single-atom nanozymes in sensing applications. We classify single-atom nanozymes based on both their structural characteristics, such as carbon-based carriers, frameworks and their derivatives, metal oxides, metal sulfides, and organic polymer carriers, and their unique catalytic properties, including peroxidase, oxidase, catalase, superoxide dismutase, and multi-enzyme mimetic activities. Furthermore, we discuss the application of single-atom nanozymes in the sensitive detection of biological small molecules, antioxidants, ions, enzyme activities and their inhibitors, as well as cells and viruses. Finally, we highlight the opportunities and challenges for advancing the practical application and further research of single-atom nanozymes in the field of sensing analysis. [ABSTRACT FROM AUTHOR]

Microalgae are naturally rich in carbohydrates, lipids, proteins, pigments, minerals, and vitamins. These metabolites make them a renewable and sustainable source of bioactive compounds in nutraceuticals, food, feed for aquaculture, and biofuels. Genetic engineering of the existing strains remains crucial in utilising and upscaling microalgae-based biorefineries. CRISPR/Cas9, TALENs, ZFNs, and genetic transformation are the established tools utilised in microalgae genetic engineering. The common genetic transformation methods include electroporation, particle bombardment (biolistics), glass-bead agitation, and Agrobacterium-mediated transformation. Expression vectors and promoters are the prerequisites in genetic engineering. The present accessibility of genome sequences and omics datasets from a diverse array of microalgae species holds promise for catalyzing strategic progress in developing a superior microalgae strain suitable for numerous applications. This paper describes the genetic engineering to enhance microalgae biomass and metabolite production, particularly lipids. The advantages and precautions to fulfil the future application of genetically engineered microalgae are also reviewed and addressed.Article highlights: Strategic genetic engineering optimises microalgae strains for enhanced lipid synthesis and biomolecule production. CRISPR/Cas9 enables precise genome modifications in microalgae, enhancing their potential for various applications. Establishing regulatory frameworks for genetically modified (GM) microalgae is crucial for safe deployment. [ABSTRACT FROM AUTHOR]

The growing interest in microalgae is driven by their potential in various bioindustries, such as biofuel production, bioremediation, and the generation of high-value biomolecules. This paper aims to systematically review the state of research on bioprospecting microalgae, their applications, and recognize trends. This study employs an exploratory and descriptive research approach, using bibliometric methods to analyze scientific production and identify emerging trends in bioprospecting microalgae research. The analysis reveals exponential publication growth, with multidisciplinary sources indicating a strong applied focus. Leading countries in this research field benefit from clear technology transfer policies, and the prevalent terms "production" and "biomass" underscore the industrial relevance. Key research areas include biofuels and bioremediation, with a combined emphasis that is often studied in cultivation and biomass production. Bioactive compounds derived from microalgae are a current trend for industrial, medical, and food applications. Although the potential for CO2 capture is acknowledged, direct studies are limited. This systematic review provides a comprehensive overview of current trends and identifies opportunities and challenges in microalgae research, highlighting its significance for sustainable development and industrial applications. [ABSTRACT FROM AUTHOR]

The Nicoya OpenSPR is a benchtop surface plasmon resonance (SPR) instrument. As with other optical biosensor instruments, it is suitable for the label-free interaction analysis of a diverse set of biomolecules, including proteins, peptides, antibodies, nucleic acids, lipids, viruses, and hormones/cytokines. Supported assays include affinity/kinetics characterization, concentration analysis, yes/no assessment of binding, competition studies, and epitope mapping. OpenSPR exploits localized SPR detection in a benchtop platform and can be connected with an autosampler (XT) to perform automated analysis over an extended time period. In this review article, we provide a comprehensive survey of the 200 peer-reviewed papers published between 2016 and 2022 that use the OpenSPR platform. We highlight the range of biomolecular analytes and interactions that have been investigated using the platform, provide an overview on the most common applications for the instrument, and point out some representative research that highlights the flexibility and utility of the instrument. [ABSTRACT FROM AUTHOR]

The design and optimization of antimicrobial materials (polymers, biomolecules, or nanocomposites) can be significantly advanced by computational methodologies like molecular dynamics (MD), which provide insights into the interactions and stability of the antimicrobial agents within the polymer matrix, and machine learning (ML) or design of experiment (DOE), which predicts and optimizes antimicrobial efficacy and material properties. These innovations not only enhance the efficiency of developing antimicrobial polymers but also enable the creation of materials with tailored properties to meet specific application needs, ensuring safety and longevity in their usage. Therefore, this paper will present the computational methodologies employed in the synthesis and application of antimicrobial polymers, biomolecules, and nanocomposites. By leveraging advanced computational techniques such as MD, ML, or DOE, significant advancements in the design and optimization of antimicrobial materials are achieved. A comprehensive review on recent progress, together with highlights of the most relevant methodologies' contributions to state-of-the-art materials science will be discussed, as well as future directions in the field will be foreseen. Finally, future possibilities and opportunities will be derived from the current state-of-the-art methodologies, providing perspectives on the potential evolution of polymer science and engineering of novel materials. [ABSTRACT FROM AUTHOR]

This paper proposes a new dielectrically modulated (DM) twin cavity nanotube biosensor and its sensitivity evaluation suitability by the transit time (τ) and device efficiency (g m / I ds ). In addition, the vertical structure of the device also helps the uniform spreading of biomolecules within the nanogap cavity region. The inner cavity of the proposed biosensor offers more space for the stabilization of biomolecules and uses the benefits of material solubility. In this paper, the sensing ability of the biosensor is examined in terms of τ and g m / I ds for five neutral biomolecules. Furthermore, the charged biomolecule and deoxyribonucleic acid (DNA) are separately investigated for positive as well as negative charge densities. Also, various optimizations on the device are analyzed for different biomolecules in this paper. [ABSTRACT FROM AUTHOR]

The gallium(III) complex of warfarin was synthesized, and its structure was determined by means of theoretical, analytical, and spectral analyses. Significant differences in the IR and Raman spectra of the complex were observed as compared to the spectra of the ligand and confirmed the suggested metal-ligand binding mode. The theoretical study of the Ga(III) complex of warfarin has been done to elucidate the structure-activity relation, inter- and intra-molecular interactions, and frontier molecular orbital energy analysis based on DFT computations. A molecular docking study has been performed to predict the biological activity of the molecule. In this paper, we report preliminary results about the cytotoxicity of the investigated compounds. The cytotoxic effects of the ligand and its Ga(III) complex were determined using the MTT method on different tumor cell lines. The screening performed revealed that the tested compounds exerted cytotoxic activity on the evaluated cell lines. [ABSTRACT FROM AUTHOR]

Distance-based topological indices are numerical parameters that are derived from the distances between atoms in a molecular structure, and they provide a quantitative measure of the topology and geometry of a molecule. The distance-based topological indices uses to predict various properties of molecules, including their boiling points, melting points, and solubility. It also predicts the biological activity of molecules, including their pharmacological and toxicological properties. Pentagonal chain molecules are organic compounds that consist of a linear chain of five-membered (pentagons) connected by carbon and bonds. These molecules have unique structural and electronic properties that make them useful in a variety of applications. Motivated by the pentagonal chain molecules, we have considered a pentagonal chain graph and it is denoted by Pn. We have computed some distance based topological indices for Pn. The paper focuses on a pentagonal chain molecules denoted by G, and derives several distance-based topological indices. These indices compromise insights into physicochemical properties, aid in identifying structural characterizations, and enhance understanding of molecular properties. [ABSTRACT FROM AUTHOR]

Several extant species of the Araucariaceae family (one of the families of conifers) were invested for the experimental artificial maturation by confined pyrolysis, in order to realize the transformation of biomolecules to geomolecules in laboratory conditions. The experimental study of diagenetized molecular signatures of the Araucariaceae species (common, inter- and infra-generic characteristics) allow to complete our knowledge in botanical palaeochemotaxonomy. Such knowledge is relevant to the reconstitution of palaeoflora and palaeoclimatic reconstruction, archaeology and environmental studies. In this work, major carbon skeleton types of Araucariaceae are detected in the organic solvent extracts of fresh and pyrolyzed plants using gas chromatography-mass spectrometry. The results show that all species of Araucariaceae are firstly characterized by a predominance of saturated tetracyclic diterpenoids. Moreover, the Araucaria genus shows a high relative abundance of bicyclic sesquiterpenoids, particularly compounds of the cadalane-type compounds accompanied by those of eudesmane-type, bisabolane-type as well as chamazulene, pentamethyl-dihydroindenes. Diterpenoids are of the labdane-type, isopimarane, abietane-type (essentially derived from abietanoic acids) as well as isohexyl alkylaromatic hydrocarbons. Compared to the tetracyclic diterpenoids, these compounds show a relatively lower abundance, reaching trace levels in the case of saturated abietanes. Distribution of sesqui- and diterpenoids of Agathis shows some similarities to that of Araucaria, with the exception of one species, in which the tetracyclic compounds are absent and the abietane-type (essentially derived from abietanoic acids) predominant. High similarities between the Wollemia and Araucaria genera are observed. Both are characterized by some high relative abundance of tetracyclic compounds with no predominance of other specific diterpenoids. [ABSTRACT FROM AUTHOR]

Presents several abstracts forming Part A of two issues of the 'Journal of Automated & Management in Chemistry' presented at the 52nd Pittsburgh Conference in New Orleans, Louisiana. 'Membrane-Gated Microchips for Nanoscale Preparative Biomolecule Separations,' by Wenju Feng, Tzu Chi Kwo, John Kirk, Jonathan Sweedler and Paul Bohn.

This document is a correction notice for a published paper titled "Effectiveness of N-Acetylcysteine in the Treatment of Renal Deterioration Caused by Long-Term Exposure to Bisphenol A." The authors apologize for any inconvenience caused and state that the scientific conclusions of the paper are unaffected. The correction involves replacing Figure 2 of the paper, which shows histopathological changes in the kidneys following long-term exposure to Bisphenol A and N-Acetylcysteine treatment. The new Figure 2 is attached to the notice. The authors of the paper are Anongporn Kobroob, Wachirasek Peerapanyasut, Sirinart Kumfu, Nipon Chattipakorn, and Orawan Wongmekiat. [Extracted from the article]

The article reports that the authors of a controversial paper on stem cells publish a correction of their work in this week's issue of "Nature." However, the authors stated that their overall conclusions still stand. In this context, the correction states that figures showing proteins on the surface of the multipotent adult progenitor cell contained many errors such as duplications. This paper challenged the prevailing idea that only stem cells derived from embryos were highly flexible.

Reports that Rui Monteiro's paper "Spatio-temporal Activation of Smad1 and Smad5 in Vivo: Monitoring Transcriptional Activity of Smad Proteins" received the award for the Best Paper published in 2004 in the "Journal of Cell Science". Profile of Monteiro; Prize; Insights about his research article.

Nitrogen (N) is a key component of fundamental biomolecules. Hence, the cycling and availability of N is a central factor governing the extent of ecosystems across the Earth. In the organic-lean sediment porewaters underlying the oligotrophic ocean, where low levels of microbial activity persist despite limited organic matter delivery from overlying water, the extent and modes of nitrogen transformations have not been widely investigated. Here we use the N and oxygen (O) isotopic composition of porewater nitrate (NO3-) from a site in the oligotrophic North Atlantic (IODP) to determine the extent and magnitude of microbial nitrate production (via nitrification) and consumption (via denitrification). We find that NO3- accumulates far above bottom seawater concentrations (~ 21 µM) throughout the sediment column (up to ~ 50 µM) down to the oceanic basement as deep as 90 mbsf, reflecting the predominance of aerobic nitrification/ remineralization within the deep marine sediments. Large changes in the δ15N and δ18O of nitrate, however, reveal variable influence of nitrate respiration across the three sites. We use an inverse porewater diffusion-reaction model, constrained by the N and O isotope systematics of nitrification and denitrification and the porewater NO3- isotopic composition, to estimate rates of nitrification and denitrification throughout the sediment column. Results indicate variability of reaction rates across and within the three boreholes that are generally consistent with the differential distribution of dissolved oxygen at this site, though not necessarily with the canonical view of how redox thresholds separate nitrate regeneration from dissimilative consumption spatially. That is, we provide isotope evidence for expanded zones of co-ocurring nitrification and denitrification. The isotope biogeochemical modeling also yielded estimates for the δ15N and δ18O of newly produced nitrate (δ15NNTR and δ18ONTR), as well as the isotope effect for denitrification (15"DNF), parameters with high relevance to global ocean models of N cycling. Estimated values of δ15NNTR were generally lower than previously reported δ15N values for sinking PON in this region. We suggest that these values can be related to sedimentary N-fixation and remineralization of the newly fixed organic N. Values of δ18ONTR generally ranged between -2.8 and 0.0 ‰, consistent with recent estimates based on lab cultures of nitrifying bacteria. Notably, some δ18ONTR values were elevated, suggesting incorporation of 18O-enriched dissolved oxygen during nitrification, and possibly indicating a tight coupling of NH4+ and NO2- oxidation in this metabolically sluggish environment. Our findings indicate that the production of organic matter by in situ autotrophy (e.g., nitrification, nitrogen fixation) supply a large fraction of the biomass and organic substrate for heterotrophy in these sediments, supplementing the small organic matter pool derived from the overlying euphotic zone. This work sheds new light on an active nitrogen cycle operating, despite exceedingly low carbon inputs, in the deep sedimentary biosphere. [ABSTRACT FROM AUTHOR]

Presents a list of articles for publication in future issues of the "European Journal of Biochemistry". Conformation of physalaemin; Association of cross-linked proteins with a specific mRNA in the cytoplasm of HeLa cells; Transport of proteins into chloroplasts.

Central America is home to one of the most abundant herpetofauna in the Americas, occupying only 7% of the continent's total area. Vipers and lizards are among the most relevant venomous animals in medical practice due to the consequences of envenomation from the bite of these animals. A great diversity of biomolecules with immense therapeutic and biotechnological value is contained in their venom. This paper describes the prominent leading representatives of the family Viperidae, emphasizing their morphology, distribution, habitat, feeding, and venom composition, as well as the biotechnological application of some isolated components from the venom of the animals from these families, focusing on molecules with potential anti-thrombotic action. We present the leading protein families that interfere with blood clotting, platelet activity, or the endothelium pro-thrombotic profile. In conclusion, Central America is an endemic region of venomous animals that can provide many molecules for biotechnological applications. [ABSTRACT FROM AUTHOR]

This document is a correction notice for a published paper titled "Multifunctional Injectable Hydrogel Loaded with Cerium-Containing Bioactive Glass Nanoparticles for Diabetic Wound Healing." The authors have identified errors in Figure 4A and in several sections of the paper, including the synthesis and characterization of BG/Ce-BG, in vivo wound healing in a diabetic skin defect model, and the wound healing effects on a diabetic skin defect model. The authors apologize for any inconvenience caused and state that the scientific conclusions of the paper are unaffected. The correction has been approved by the Academic Editor and the original publication has been updated. [Extracted from the article]

This research paper presents a misaligned double-gate junctionless Metal-Oxide-Semiconductor Field-Effect Transistor for label-free detection of biomolecules. The proposed biosensor combines the advantages of being junctionless, as well as possessing double and misaligned gate MOSFETs, which results in improved sensitivity and selectivity for biological recognition. The results show that the proposed biosensor can effectively detect biomolecules and has the potential for use in various applications. Biosensors have become an important tool in various fields, such as healthcare, environmental monitoring, and food safety due to their ability to detect biomolecules. MOSFETs have been widely used as biosensors due to their less complex structure and ease of use. However, traditional MOSFETs have limitations in terms of sensing performance, and there is a need for improved designs that overcome these limitations. The results of this study show that the proposed biosensor can effectively detect various biomolecules, such as protein and DNA. The proposed biosensor design has the potential to revolutionize the field of biosensors. Its combination of improved sensitivity and selectivity makes it a valuable tool for various applications. In conclusion, this research paper presents a dielectric modulated novel misaligned double-gate junctionless MOSFET-based biosensor, promising improved sensing performance in various applications. The proposed design provides a valuable contribution to the field of biosensors and has the potential to revolutionize the way biomolecules are detected. [ABSTRACT FROM AUTHOR]

The article presents information on various research papers which will be published in the forthcoming issue of the "European Journal of Biochemistry". Some of the papers discusses are "Enzymatic Synthesis of Neolactotetraosylceramide by the N-Acctyllactosamine Synthase of Human Serum". "Rate of Transplantation and Kinetics of Processing of Newly Synthesized Molecules of Two Major Outer-Membrane Proteins, the OmpA and OmpF Proteins of Escherichia Coli," by the researchers I. Crowlesmith and K. Gamon.

This article presents a list of some of the forthcoming papers in biochemistry to be published in this journal. Some of the papers listed are "The Organization of the Chloroplast DNA in wheat and maize in the region containing the LS Gene," by B. Koller, H. Delius and T.A. Dyer, "Effect of Carbamination on the Buffering Power of Purified Human Hamoglobins A Solutions At Two Temperatures," by M. Castaing, E. Bursaux and C. Poyart, "The Complete Nucleotide of the Chicken Ovotransferrin mRNA," by J.M. Jeltsch and P. Chambon, "The Primary Structure of Hen Ovotransferrin," by J. Williams, T.C. Elleman, I.B. Kington, A.G. Wilkins and K.A. Kuhn.

The article reports on the research conducted by David Bartel and Nikolaus Rajewsky regarding the implication of RNA to the production of cellular proteins in the U.S. When both intellectuals presented their work during the molecular biology symposium in Miami, they discovered that they were tackling the same issue. To unveil the mystery behind these cellular proteins, they need to look at changes in thousands of proteins at once and detect the differences in protein abundance. They found a glean insight into how miRNA act to fine tune the levels of thousands of proteins in a cell.

The article focuses on the reasons why the author has spent nine years pursuing a map of the 450-protein nuclear pore complex (NPC). His fascination by how things move in and about the cell's nucleus contribute with his determination to mapping huge complexes. The author, together with his colleagues, has generated proteomics, biochemical and mass spectrometry data for all NPC proteins. Fitting each protein's volume into its hotspot gives a physical map of the pore. It is considered that this serves as a powerful approach to solve large assemblies.

The article focuses on the development of methods for making very sensitive measurements of biological molecules and nanoparticles by Scott Manalis and his group at the Massachusetts Institute of Technology in Cambridge, Massachusetts. Manali said that they wanted to develop methods for label-free detection that could be as sensitive as fluorescence. After three years, they came up with a vacuum-packaged resonator that could weigh individual nanoparticles, single bacteria and protein monolayers.

The article discusses the new properties and roles for eosinophils in disease. The author said that much of the emphasis on the role of eosinophils in disease before centered on their presumed capacity to neutralize mediators of inflammatory responses. Today the emphasis has changed entirely, and eosinophils are now regarded by many to be primary mediators of inflammatory responses. Future work on eosinophils is likely to be influenced by the development of molecular biological approaches.

The marine environment has remained a source of novel biological molecules with diversified applications. The ecological and biological diversity, along with a unique physical environment, have provided the evolutionary advantage to the plant, animals and microbial species thriving in the marine ecosystem. In light of the fact that marine microorganisms frequently interact symbiotically or mutualistically with higher species including corals, fish, sponges, and algae, this paper intends to examine the potential of marine microorganisms as a niche for marine bacteria. This review aims to analyze and summarize modern literature data on the biotechnological potential of marine fungi and bacteria as producers of a wide range of practically valuable products (surfactants, glyco-and lipopeptides, exopolysaccharides, enzymes, and metabolites with different biological activities: antimicrobial, antitumor, and cytotoxic). Hence, the study on bioactive secondary metabolites from marine microorganisms is the need of the hour. The scientific novelty of the study lies in the fact that for the first time, the data on new resources for obtaining biologically active natural products -- metabolites of marine bacteria and fungi -- were generalized. The review investigates the various kinds of natural products derived from marine microorganisms, specifically focusing on marine bacteria and fungi as a valuable source for new natural products. It provides a summary of the data regarding the antibacterial, antimalarial, anticarcinogenic, antibiofilm, and anti-inflammatory effects demonstrated by marine microorganisms. There is currently a great need for scientific and applied research on bioactive secondary metabolites of marine microorganisms from the standpoint of human and animal health. [ABSTRACT FROM AUTHOR]

Metabolic myopathies are a group of genetic disorders that affect the normal functioning of muscles due to abnormalities in metabolic pathways. These conditions result in impaired energy production and utilization within muscle cells, leading to limitations in muscle function with concomitant occurrence of related signs and symptoms, among which fatigue is one of the most frequently reported. Understanding the underlying molecular mechanisms of muscle fatigue in these conditions is challenging for the development of an effective diagnostic and prognostic approach to test targeted therapeutic interventions. This paper outlines the key biomolecules involved in muscle fatigue in metabolic myopathies, including energy substrates, enzymes, ion channels, and signaling molecules. Potential future research directions in this field are also discussed. [ABSTRACT FROM AUTHOR]