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Despite the rapid development of mobile health based on wearable devices in recent years, lack of access to biochemical detection remains a vital challenge for most commercial wearable devices, which hinders the provision of effective electronic health records (EHRs) for disease control strategies, and further constraining the development of personalized precision medicine. Herein, we propose a strategy to graft biochemical detection function onto commercial bracelet. Different from the conventional development process of designing a completely new wearable biochemical device, we prefer to upgrade existing commercial wearable device to achieve simpler, faster, and more effective research and commercialization processes. An affordable and user-friendly biochemical button module has been designed that enables to integrate sensitive, specific, and rapid biochemical detection function into the idle space on the strap of the bracelet without increasing the size of the main body. This "Smart Bracelet Plus" shows the ability to simultaneously monitor physical and biochemical signals, and will serve as a reliable and systematic personal diagnostics and monitoring platform for providing real-time EHRs for disease control strategies and improving the efficiency of the healthcare system., Competing Interests: Declaration of competing interest Xunshun Tao have a significant interest in Nanjing Ziqishun Biotechnology Co., Ltd, a company that have a commercial interest in the detailed mechanical and electrical design of this system. The potential individual conflict of interest has been reviewed and managed by South China University of Technology. Junhao Chen and Junfei Tian have potential interest in the results of this research and technology. Other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Revolutionary all-in-one RPA-CRISPR assays are rapidly becoming the most sought-after tools for point-of-care testing (POCT) due to their high sensitivity and ease of use. Despite the availability of one-pot methods for specific targets, the development of more efficient methods for new targets remains a significant challenge. In this study, we present a rapid and universal approach to establishing an all-in-one RPA-Cas12a method CORDSv2 based on rational balancing amplification and Cas12a cleavage, which achieves ultrasensitive detection of several targets, including SARS-CoV-2, ASFV, HPV16, and HPV18. CORDSv2 demonstrates a limit of detection (LOD) of 0.6 cp/μL and 100% sensitivity for SARS-CoV-2, comparable to qPCR. Combining with our portable device(hippo-CORDS), it has a visual detection LOD of 6 cp/μL and a sensitivity up to 100% for SARS-CoV-2 and 97% for Ct<35 ASFV samples, surpassing most one-pot visual methods. To simplify and accelerate the process for new targets, we also develop a de novo autodesigner by which the optimal couples of primers and crRNA can be selected rapidly. As a universal all-in-one RPA-CRISPR method for on-site testing, CORDSv2 becomes an attractive choice for rapid and accurate diagnosis in resource-limited settings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Microcystins with leucine arginine (MC-LR) is a virulent hepatotoxin, which is commonly present in polluted water with its demethylated derivatives [Dha 7 ] MC-LR. This study reported a low-cost molecularly imprinted polymer network-based electrochemical sensor for detecting MC-LR. The sensor was based on a three-dimensional conductive network composed of multi-walled carbon nanotubes (MWCNTs), graphene quantum dots (GQDs), and gold nanoparticles (AuNPs). The molecularly imprinted polymer was engineered by quantum chemical computation utilizing p-aminothiophenol (p-ATP) and methacrylic acid (MAA) as dual functional monomers and L-arginine as a segment template. The electrochemical reaction mechanism of MC-LR on the sensor was studied for the first time, which is an irreversible electrochemical oxidation reaction involving an electron and two protons, and is controlled by a mixed adsorption-diffusion mechanism. The sensor exhibited a great detection response to MC-LR in the linear range of 0.08-2 μg/L, and the limit of detection (LOD) is 0.0027 μg/L (S/N = 3). In addition, the recoveries of the total amount of MC-LR and [Dha 7 ] MC-LR in the actual sample by the obtained sensor were in the range from 91.4 to 116.7%, which indicated its great potential for environmental detection.

Over the last few years, the focus of researchers have been set on enzyme engineering and enzyme immobilization technology using natural polysaccharides as promising and green supporting materials to address the challenges of free enzymes for various applications. Polysaccharides have been extensively implemented as enzyme carriers because they can be easily modified chemically according to the nature of immobilization. This process improves the stability and lifetime of laccase in catalytic reactions. Additionally, the selectivity of the enzymes can be preserved for particular application after immobilization onto polysaccharides. This review paper reveals the significance and potential of natural polysaccharides (including cellulose, chitosan, and alginate) and their composites as support materials for the laccases immobilization to expand the modified biocatalysts for industrial applications. Moreover, the roles of immobilized laccases are discussed from a fundamental point of view to elucidate their catalytic mechanisms as biocatalysts in the detection and degradation of environmental contaminants., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

As one type of the solid wastes, the increasing contamination of waste cellulose diacetate (CDA) from discarded cigarette filters is a growing problem worldwide. Finding a facile and suitable approach to convert the CDA into value-added materials is of significance. Herein, we reported a green, simple and effective method to reuse CDA as precursor for preparing fluorescence N-doped carbon dots (N-CDs) via one-pot hydrothermal carbonization in aqueous solution with low-cost ammonium hydroxide as the passivation agent. The N-CDs showed a quantum yield up to 22.4% with a maximum emission at 415 nm and excitation at 320 nm. Interestingly, the N-CDs exhibited high selectivity toward tetracycline (TC) as their fluorescence was obviously quenched by TC as a result of inner-filter effect. A linear relationship was fabricated over concentration range of 0-80 μM with a detection limit of 0.06 μM. Moreover, the N-CDs could also be applied as fluorescent ink for anti-forgery., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Cellulose has attracted much interest, particularly in medical applications such as advanced biosensing devices. Cellulose could provide biosensors with enhanced biocompatibility, biodegradability and non-toxicity, which could be useful for biosensors. Thus, they play a significant role in environmental monitoring, medical diagnostic tools, forensic science, and foodstuff processing safety applications. This review summarizes the recent developments in cellulose-based biosensors targeting the molecular design principles toward medical detection purposes. The recognition/detection mechanisms of cellulose-based biosensors demonstrate two major classes of measurable signal generation, including optical and electrochemical cellulosic biosensors. As a result of their simplicity, high sensitivity, and low cost, cellulose-based optical biosensors are particularly of great interest for including label-free and label-driven (fluorescent and colorimetric) biosensors. There have been numerous types of cellulose substrates employed in biosensors, including several cellulose derivatives, nano-cellulose, bacterial cellulose, paper, gauzes, and hydrogels. These kinds of cellulose-based biosensors were discussed according to their preparation procedures and detection principle. Cellulose and its derivatives with their distinctive chemical structure have demonstrated to be versatile materials, affording a high-quality platform for accomplishing the immobilization process of biologically active molecules into biosensors. Cellulose-based biosensors exhibit a variety of desirable characteristics, such as sensitivity, accuracy, convenience, quick response, and low-cost. For instance, cellulose paper-based biosensors are characterized as being low-cost and easy to operate, while nano-cellulose biosensors are characterized as having a good dispersion, high absorbance capacity, and large surface area. Cellulose and its derivatives have been promising materials in biosensors which could be employed to monitor various bio-molecules, such as urea, glucose, cell, amino acid, protein, lactate, hydroquinone, gene, and cholesterol. The future interest will focus on the design and construction of multifunctional, miniaturized, low-cost, environmentally friendly, and integrated biosensors. Thus, the production of cellulose-based biosensors is very important.

Sensors are of increasing interest since they can be applied to daily life in different areas from various industrial sectors. As a natural nanomaterial, nanocellulose plays a vital role in the development of novel sensors, particularly in the context of constructing multidimensional architectures. This review summarizes the utilization of nanocellulose including cellulose nanofibers, cellulose nanocrystals, and bacterial cellulose for sensor design, mainly focusing on the influence of nanocellulose on the sensing performance of these sensors. Special attention is paid to nanocellulose in different forms (1D, 2D, and 3D) to highlight the impact of nanocellulose constructed structures. The aim is to provide a critical review on the most recent progress (especially after 2017) related to nanocellulose-containing sensors, since there are significantly increasing research activities in this area. Moreover, the outlook for the development of nanocellulose-containing sensors is also provided at the end of this work., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Combining the stability of solid-state nanopores with the unique sensing properties of biological components in a miniaturized electrical hybrid nanopore device is a challenging approach to advance the sensitivity and selectivity of small-molecule detection in healthcare and environment analytics. Here, we demonstrate a simple method to design an electrical hybrid nanosensor comprising a bacterial binding protein tethered to a solid-state nanopore allowing high-affinity detection of phosphonates. The diverse family of bacterial substrate-binding proteins (SBPs) binds specifically and efficiently to various substances and has been implicated as an ideal biorecognition element for analyte detection in the design of hybrid bionanosensors. Here, we demonstrate that the coupling of the purified phosphonate binding protein PhnD via primary amines to the reactive NHS groups of P(DMAA- co -NMAS) polymers inside a single track-etched nanopore in poly(ethylene terephthalate) (PET) foils results in ligand-specific and concentration-dependent changes in the nanopore current. Application of the phosphonate 2-aminoethylphosphonate (2AEP) or ethylphosphonate (EP) induces a large conformational rearrangement in PnhD around the hinge in a venus flytrap mechanism resulting in a concentration depended on increase of the single pore current with binding affinities of 27 and 373 nM, respectively. Thus, the specificity and stability of this simple hybrid sensor concept combine the advantages of both, the diversity of ligand-specific substrate-binding proteins and solid-state nanopores encouraging further options to produce robust devices amenable to medical or environmental high-throughput-based applications in nanotechnology.

Background: Biosensors are widely applied for the detection of bio-molecules in blood glucose , cholesterol, and gene. Cellulose as the most dominating natural polymer has attracted more and more interest, especially in the field of medicine such as advanced medical diagnosis. Cellulose could endow biosensors with improved biocompatibility, biodegradability and nontoxicity, which could help in medical diagnosis. This mini-review summarizes the current development of cellulose-based biosensors as well as their applications in medical diagnosis in recent years., Methods: After reviewing recent years' publications we can say that, there are several kinds of cellulose used in biosensors including different cellulose derivatives, bacterial cellulose and nanocellulose. Different types of cellulose-based biosensors, such as membrane, nano-cellulose and others were briefly described in addition to the detection principle. Cellulose-based biosensors were summarized as in the previous papers. The description of various methods used for preparing cellulose-based biosensors was also provided., Results: Cellulose and its derivatives with their unique chemical structure proved to be versatile materials providing a good platform for achieving immobilizing bioactive molecules in biosensors. These cellulose-based biosensors possess various desirable properties such as accuracy, sensitivity, convenience, low cost and fast response. Among them, cellulose paper-based biosensors have the advantages of low cost and easy operation. Nano-cellulose has unique properties such as a large aspect ratio, good dispersing ability and high absorption capacity., Conclusion: Cellulose displays a promising application in biosensors which could be used to detect different bio-molecules such as glucose, lactate, urea, gene, cell, amino acid, cholesterol, protein and hydroquinone. In future, the attention will be focused on designing miniaturized, multifunctional, intelligent and integrated biosensors. Creation of low cost and environmentally friendly biosensors is also very important., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Fast and accurate detection of S. aureus and effectively kill S. aureus in the bloodstream in low doses acted as key roles in medicine and microbiology studies. In this work, sufonated-hyaluronic acid (S-HA) terminated magnetic mesoporous silica nanoparticles (MMSNs) loaded with vancomycin was successfully prepared, and S. aureus antibody was further modified on the surface of MMSNs (Ab@S-HA@MMSNs) by amidation reaction. The result showed that Ab@S-HA@MMSNs were 240 nm-sized spheres with worm-like mesoporous channels. With the aid of magnetic interaction, Ab@S-HA@MMSNs were modified on the surface of magnetic glassy carbon electrode (MGCE). This prepared immunosensor exhibited an excellent detection limit and linear range, and possessed good selectivity, stability and reproducibility. Besides, since the S-HA terminated MMSNs have anticoagulant property, the Ab@S-HA@MMSNs/MGCE showed antiadhesion property, which ensure that it can be directly applied to detect the amount of S. aureus in whole blood. What's more, with an increasing amount of S. aureus arriving at MGCE, the capping Ab@S-HA@MMSNs were degraded by Hyal which was secreted by S. aureus, and the packaged vancomycin was subsequently released. Ultimately, S. aureus can be effectively killed. Therefore, this integrated platform would be a promising multifunctional platform for achieving accurate diagnosis and efficient treatment of S. aureus bloodstream infection., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The conventional test strip has usually only one electrochemical reaction channel, which requires two times figure punctures for the self-management of patients suffering from both diabetes and gout. Considering the large number of such patients and for the sake of reducing their pains, we report an enzymatic test strip which can simultaneously monitor glucose and uric acid (UA) with only one fingertip blood droplet. The proposed test strip is composed of dual channels. The glucose in blood is detected in the 1st channel above on the substrate and the UA is characterized in the 2nd channel located at the bottom of the substrate. The proposed design intensively matches the requirement of those patients simultaneously suffering from diabetes and gout. We carried out comparative investigations on the proposed test strip and clinical biochemical analyser, which indicates a good agreement and proved the reliability and accuracy of the proposed test strip, as promising solution for the fast growth of family health management market., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Promoted by the localized surface plasmon resonance nanotechnology, a simple and sensitive plasmonic aptamer nanosensor (nanoaptasensor) on an individual Au@Ag core-shell nanocube (Au@Ag NC) has been proposed for real-time monitoring of the formation process of G-quadruplex structures and label-free analysis of potassium ions (K(+) ). In particular, the analysis of the thermodynamic parameters indicates that there are two types of binding states accompanied with a remarkable change of free energy (ΔG) in the sequential folding process of telomere DNA sequence. This nanoaptasensor has raised promising applications in monitoring the dynamic process of the structural switch of the G-quadruplex., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Integrating polypyrrole-cellulose nanocrystal-based composites with glucose oxidase (GOx) as a new sensing regime was investigated. Polypyrrole-cellulose nanocrystal (PPy-CNC)-based composite as a novel immobilization membrane with unique physicochemical properties was found to enhance biosensor performance. Field emission scanning electron microscopy (FESEM) images showed that fibers were nanosized and porous, which is appropriate for accommodating enzymes and increasing electron transfer kinetics. The voltammetric results showed that the native structure and biocatalytic activity of GOx immobilized on the PPy-CNC nanocomposite remained and exhibited a high sensitivity (ca. 0.73 μA·mM(-1)), with a high dynamic response ranging from 1.0 to 20 mM glucose. The modified glucose biosensor exhibits a limit of detection (LOD) of (50 ± 10) µM and also excludes interfering species, such as ascorbic acid, uric acid, and cholesterol, which makes this sensor suitable for glucose determination in real samples. This sensor displays an acceptable reproducibility and stability over time. The current response was maintained over 95% of the initial value after 17 days, and the current difference measurement obtained using different electrodes provided a relative standard deviation (RSD) of 4.47%.

Novel self-assembled water-soluble nanomicelles that contain fluorescent conjugated polymers (poly(9,9-dioctylfluorene) (PFO) or poly[2,7-(9,9-dihexylfluorene)-alt-4,4'-phenylether] (PF-PE)) have been obtained and used as the highly sensitive/selective platform for Sudan dye detection. The Fluorescent nanomicelles exhibited a highly selective fluorescence quenching by the prohibited food additive Sudan I, while not for the natural pigments: Capsanthin and Beta-carotene, due to the more suitable matching of the LUMOs (lowest unoccupied molecular orbital) of the conjugated polymers with that of Sudan I molecules. The Stern-Volmer constants (K(SV)) of PF-PE/F127 and PFO/F127 for Sudan I were 1,040,480 and 665,000 M(-1), respectively, which were more than 100 times higher than those of the same conjugated polymers in the orgainc solvents. The significantly enhanced sensitivity was due to the collective effect of the F127 micelles to both chromophore and analyte, through which the fluorophone-analyte binding interaction is significantly strengthened and efficient photoinduced charge transfer occurs. The as-proposed materials and approach may be potentially applied in the real-time food safety screening.

This work reports a simple method to form and visualize individual polyelectrolyte-nanoparticle necklace-like structures on paper, which is applicable to other porous surfaces. In this work, one-dimensional necklaces of negatively charged gold nanoparticles (AuNPs) have been electrostatically assembled along the backbone of a cationic polyacrylamide (CPAM) chain adsorbed on paper. The process involves rapidly passing a dilute CPAM solution through filter paper, adsorbing the polyelectrolyte on the surface, followed by the immediate filtration of an AuNP suspension through the same filter paper. The nanoparticles used were negatively charged, citrate ion capped AuNPs with an average diameter of 20 nm. Scanning electron microscopy images of the dried paper sample showed that the AuNP necklaces were adsorbed in a perpendicular direction to that of the cellulose fibers and along the length of the CPAM molecules which were draped over the fibers. The effects of CPAM polymer concentration, charge density, and molecular weight on such assembly of AuNPs were studied. This technique enables the visualization of polyelectrolyte molecules and the formation of very well organized and reproducible polyelectrolyte-nanoparticle necklaces on a porous, three-dimensional substrate., (Copyright © 2013 Elsevier Inc. All rights reserved.)

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 117 fmol 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 © 2011 Elsevier B.V. All rights reserved.)

A fast and sensitive method based on fluorescent carboxymethyl chitosan/CdS quantum dots (CMCS-CdS QDs) composites was developed for specific detection of Staphylococcus aureus in food and the environment. Fluorescent CMCS-CdS QDs were prepared in aqueous solution through a green method. A human immunoglobulin (IgG) antibody was then bioconjugated to the QDs in the presence of 1-ethyl-3-(3)-dimethylaminopropyl carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to make a novel type of mono-dispersed water-soluble fluorescent bioprobes. The fluorescent bioprobes were employed to identify S. aureus by incubating them with the bacteria for a certain time and observing the marked cells under fluorescence microscopy after removing free fluorescent QDs. Fluorescence microscopy images showed the S. aureus cells were successfully recognized by the bioprobes. Several other bacteria commonly found in environment such as Escherichia coli and Bacillus subtilis were also incubated with the bioprobes to test their specificity. It was found that the novel QDs-CMCS-IgG bioprobes had specific identification to S. aureus cells. Fluorescence measurement using a luminescence spectrometer could be applied to quantify S. aureus cells. The fluorescence intensity of the samples at 600 nm was proportional to the cell concentration in the range of 10(3)-10(7) cfu/ml, and the detection limit was as low as 900 cfu/ml. Considering the simplicity and cost-efficiency of this method, its application in the identification and quantification of bacteria in clinical, food and environmental samples is anticipated., (© Koninklijke Brill NV, Leiden, 2011)