Novel theranostic wounds dressing based on pH responsive alginate hydrogel/graphene oxide/levofloxacin modified silk.

Integrating pH sensor with controlled antibiotic release is fabricated on silk to create a theranostic wound dressing. Alginate (ALG) hydrogel and graphene oxide (GO) loaded with levofloxacin (LVX) and a pH indicator are applied to fabricate a pH-responsive theranostic wound dressing. The modified silk color changes from yellow to green in response to elevated skin pH, indicating the skin infection.

Smartphone based wearable sweat glucose sensing device correlated with machine learning for real-time diabetes screening.

Background: Diabetes is a significant health threat, with its prevalence and burden increasing worldwide indicating its challenge for global healthcare management. To decrease the disease severity, the diabetic patients are recommended to regularly check their blood glucose levels. The conventional finger-pricking test possesses some drawbacks, including painfulness and infection risk.

Optical biosensors for diagnosis of COVID-19: nanomaterial-enabled particle strategies for post pandemic era.

The COVID-19 pandemic underlines the need for effective strategies for controlling virus spread and ensuring sensitive detection of SARS-CoV-2. This review presents the potential of nanomaterial-enabled optical biosensors for rapid and low-cost detection of SARS-CoV-2 biomarkers, demonstrating a comprehensive analysis including colorimetric, fluorescence, surface-enhanced Raman scattering, and surface plasmon resonance detection methods. Nanomaterials including metal-based nanomaterials, metal-organic frame-based nanoparticles, nanorods, nanoporous materials, nanoshell materials, and magnetic nanoparticles employed in the production of optical biosensors are presented in detail.

Surface-engineered natural fibers: Emerging alternative substrates for chemical sensor applications: A review.

Natural fiber has become one of the most widely used alternative materials for chemical sensor fabrication due to its advantages, such as biocompatibility, flexibility, and self-microfluidic properties. Enhanced natural fiber surface has been used as a substrate in colorimetric and electrochemical sensors. This review focuses on improving the natural fiber properties for preparation as a substrate for chemical sensors.

Fabrication of Silver Nanoparticle Loaded into Nanocellulose Derived from Hemp and Poly(vinyl alcohol)-Based Composite as an Electrode for Electrochemical Sensors for Lactate Determination.

Nanocellulose derived from hemp (HNC) with the addition of silver nanoparticles (AgNPs) is utilized for improving the electrochemical sensing performances for lactate detection. Initially, HNC is chemically extracted and purified by using alkali treatment and acid hydrolysis. Then, AgNPs are nucleated in situ by the self-reduction process prior to forming a composite with poly(vinyl alcohol) (PVA).

Zwitterionic hydrogel for preserving stability and activity of oxidase enzyme for electrochemical biosensor.

Enzymatic electrochemical biosensor is the most common analytical platform for medical diagnosis. To mimic the biological environment of the enzyme for maintaining the function of biosensor, zwitterionic hydrogels have been recognized as effective matrices for enzymatic immobilization. Herein, a zwitterionic hydrogel derived from a copolymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-N-methacryloyloxyethyl tyrosine methylester (MAT)] (PMM) was firstly applied as versatile coating to preserve stability and activity of oxidase enzymes, glucose oxidase (GOx) and lactate oxidase (LOx) for enzymatic electrochemical sensor.

Bacterial cellulose composite hydrogel for pre-concentration and mass spectrometric detection of thiol-containing biomarker.

Simple soaking of bacterial cellulose (BC) membrane in carboxymethyl cellulose (CMC) solution yielded BC/CMC hydrogel having re-swellable property. Then, gold nanoparticles (AuNPs) were embedded in the BC/CMC hydrogel via in situ chemical reduction to form BC/CMC/AuNPs composite hydrogel. It was found that the composite hydrogel exhibited physical/chemical characteristics similar to those of BC.

Graphene oxide-alginate hydrogel-based indicator displacement assay integrated with diaper for non-invasive Alzheimer's disease screening.

Pyrocatechol violet/copper ion-graphene oxide/alginate (PV/Cu-GO/Alg) hydrogel was fabricated and applied as a colorimetric sensor for monitoring urinary cysteine via an indicator-displacement assay (IDA) and Cu-cysteine affinity pair. The hydrogel-based sensor was formed by Ca cations cross-linked PV/Cu-GO/Alg. The morphologies of hydrogel were characterized by field-emission scanning electron microscopy with energy-dispersive X-ray spectroscopy and Fourier-transform Raman spectroscopy.

Alternative platform for COVID-19 diagnosis based on AuNP-modified lab-on-paper.

COVID-19 has caused global health problems, and so rapid diagnosis is crucial to slow spread of the disease. Herein, a novel lab-on-paper screening method for SARS-CoV-2 Omicron BA.2 variant was developed using a gold nanoparticle-based colorimetric biosensor along with sensitive detection of SARS-CoV-2 antigen using laser desorption ionization-mass spectrometry (LDI-MS).

Carbonization of self-reduced AuNPs on silk as wearable skin patches for non-invasive sweat urea detection.

Flexible conductive skin patches were readily fabricated on silk fabric by in situ deposition of gold nanoparticles (AuNPs) followed by carbonization. The carbonized AuNPs-silk with high flexibility was characterized by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and Fourier transform Raman spectroscopy (FT-Raman) to verify the well arrangement surface and desired chemical binding. The conductivity of silk skin patch, measured by a four-point probe, was found to be 109.

Paper-Based Screen-Printed Ionic-Liquid/Graphene Electrode Integrated with Prussian Blue/MXene Nanocomposites Enabled Electrochemical Detection for Glucose Sensing.

As glucose biosensors play an important role in glycemic control, which can prevent the diabetic complications, the development of a glucose sensing platform is still in needed. Herein, the first proposal on the in-house fabricated paper-based screen-printed ionic liquid/graphene electrode (SPIL-GE) modified with MXene (TiCT), prussian blue (PB), glucose oxidase (GOx), and Nafion is reported. The concentration of PB/TiCT was optimized and the optimal detection potential of PB/TiCT/GOx/Nafion/SPIL-GE is -0.

Room Temperature Nanographene Production via CO Electrochemical Reduction on the Electrodeposited Bi on Sn Substrate.

Electrochemical reduction of carbon dioxide (CORR) to crystalline solid carbon at room temperature is challenging, but it is a providential CO utilization route due to its indefinite storage and potential applications of its products in many advanced technologies. Here, room-temperature synthesis of polycrystalline nanographene was achieved by CORR over the electrodeposited Bi on Sn substrate prepared with various bismuth concentrations (0.01 M, 0.

A portable blood lactate sensor with a non-immobilized enzyme for early sepsis diagnosis.

Early determination of blood lactate levels may accelerate the detection of sepsis, one of the most time-sensitive illnesses. We developed and validated a portable blood lactate detection kit for clinical screening that can measure early bedside lactate levels in intensive care unit (ICU) patients suspected of having sepsis. A TiO sol-G nanocomposite was prepared and coated on a screen-printed carbon electrode (SPCE) integrated with non-immobilized lactate oxidase (LOx) to produce a novel lactate biosensor with high sensitivity and high storage stability for human blood lactate measurement.

Conductive electrospun composite fibers based on solid-state polymerized Poly(3,4-ethylenedioxythiophene) for simultaneous electrochemical detection of metal ions.

Conductive composite fibers containing poly (3,4-ethylenedioxythiophene) (PEDOT) and silver nanoparticles (AgNPs) were fabricated by emulsion electrospinning of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) in toluene together with aqueous solution of poly (vinyl alcohol) (PVA) and silver nanoparticles (AgNPs) in the presence of sodium dodecylsulfate followed by heat treatment at 70 °C to convert DBEDOT to conductive PEDOT via solid state polymerization (SSP). The composite fibers were characterized by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis. The PEDOT/PVA/AgNPs composite fibers deposited on a screen-printed carbon electrode (SPCE) surface exhibited good electrochemical response and was applied for simultaneous detection of heavy metal ions in a mixture, namely Zn(II), Cd(II), and Pb(II) via square wave anodic stripping voltammetry (SWASV).

Non-invasive electrochemical immunosensor for sweat cortisol based on L-cys/AuNPs/ MXene modified thread electrode.

Thread-based electrochemical immunosensor is fabricated for non-invasive detection of cortisol in sweat by immobilization of anti-cortisol on L-cys/AuNPs/MXene modified conductive thread electrode. MXene and AuNPs increase the surface area of conductive thread electrode and facilitate anti-cortisol immobilization leading to enhanced sensor sensitivity. Anti-cortisol is immobilized on L-cys/AuNPs/MXene modified electrode by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide coupling agents.

TiO/MXene-PVA/GO hydrogel-based electrochemical sensor for neurological disorder screening via urinary norepinephrine detection.

A hydrogel based on titanium dioxide/MXene with polyvinyl alcohol/graphene oxide (TiO/MXene-PVA/GO) composite was successfully formulated and applied to modify a screen-printed carbon electrode (SPCE) for urinary norepinephrine (NE) detection. The characterization confirmed that a nanocomposite hydrogel structure of TiO/MXene-PVA/GO was formed. The as-prepared hydrogel substantially enhanced the sensor performances due to electrocatalytic activity of TiO, high conductivity of MXene, and auto-sample preconcentration via PVA/GO hydrogel.

Non-invasive wearable chemical sensors in real-life applications.

Over the past decade, non-invasive wearable chemical sensors have gained tremendous attention in the field of personal health monitoring and medical diagnosis. These sensors provide non-invasive, real-time, and continuous monitoring of targeted biomarkers with more simplicity than the conventional diagnostic approaches. This review primarily describes the substrate materials used for sensor fabrication, sample collection and handling, and analytical detection techniques that are utilized to detect biomarkers in different biofluids.

A non-enzymatic disposable electrochemical sensor based on surface-modified screen-printed electrode CuO-IL/rGO nanocomposite for a single-step determination of glucose in human urine and electrolyte drinks.

A non-enzymatic disposable electrochemical sensor coupled with an automated sample pretreatment paper-based device was developed to avoid an additional sample preparation step for glucose determination in human urine and electrolyte drinks. The automated sample pretreatment paper-based device was successfully fabricated by the simple coating of a strong alkaline solution on a patterned wax paper, and then attached on an electrochemical sensor. The nanocomposite of copper oxide nanoparticles, ionic liquid and reduced graphene oxide (CuO-IL/rGO) modified on the screen-printed carbon electrode (SPCE) was created and used as a non-enzymatic electrochemical glucose sensor.

Enhanced and Selective MALDI-MS Detection of Peptides via the Nanomaterial-Dependent Coffee Ring Effect.

Nanomaterials have been explored as alternative matrices in MALDI-MS to overcome some of the limitations of conventional matrices. Recently, we demonstrated a new means by which nanomaterials can improve peptide ionization and detection in MALDI-MS analyses by exploiting the tendency of nanomaterials to form "coffee rings" upon drying from liquids. In the current work, we investigate how nanomaterial size and composition affect the signal enhancement of peptides through the coffee-ring effect.

Bacterial cellulose-based re-swellable hydrogel: Facile preparation and its potential application as colorimetric sensor of sweat pH and glucose.

Direct deposition of the negatively charged polyelectrolyte, carboxymethyl cellulose (CMC), into a bacterial cellulose (BC) matrix was used as a simple route to fabricate a re-swellable and biocompatible cellulose-based hydrogel. As a result of this non-destructive approach, the physical and mechanical property of the original BC were well-preserved within the resulting BC/CMC hydrogel. As a BC/CMC-based colorimetric pH sensor, it exhibited a rapid response with an easy color differentiation between each pH by the naked eye, and wide linear range of pH 4.

Label-free anti-Müllerian hormone sensor based on polyaniline micellar modified electrode.

A label-free electrochemical immunosensor based on polyaniline (PANI) micellar electrode was firstly fabricated for direct AMH detection. To control the size regularity of PANI, a micelle-based method using ammonium peroxydisulfate (APS) as a reducing agent was employed in the polymerization process. The Anti-AMH antibodies were readily immobilized onto PANI via peptide bond to enhance the sensor specificity and sensitivity.

Recent Advances in Microfluidic Paper-Based Analytical Devices toward High-Throughput Screening.

Microfluidic paper-based analytical devices (µPADs) have become promising tools offering various analytical applications for chemical and biological assays at the point-of-care (POC). Compared to traditional microfluidic devices, µPADs offer notable advantages; they are cost-effective, easily fabricated, disposable, and portable. Because of our better understanding and advanced engineering of µPADs, multistep assays, high detection sensitivity, and rapid result readout have become possible, and recently developed µPADs have gained extensive interest in parallel analyses to detect biomarkers of interest.

Colorimetric sensor and LDI-MS detection of biogenic amines in food spoilage based on porous PLA and graphene oxide.

Biogenic amines are the important markers for food spoilage, thus, an on-package sensor for biogenic amine detection is crucial for food quality control. A dual detection platform including colorimetry and LDI-MS was developed for screening and quantitative determining of biogenic amines. Porous PLA film, was fabricated using calcium carbonate nanoparticles to enhance film porosity leading to increased surface area of colorimetric sensor.

3D paper-based microfluidic device: a novel dual-detection platform of bisphenol A.

A novel platform of microfluidic paper-based analytical devices (μPADs) for dual detection of bisphenol A (BPA), a model analyte, was fabricated using an electronic digital plotter to create the stacked layer of μPADs and generate the lateral-flow channel without using an external pump. Two detection techniques, including electrochemical detection and laser desorption ionization mass spectrometric detection (LDI-MS), were used complementarily to improve the precision in the detection of BPA. The fluid sample was delivered to both detection zones by the capillary action, automatically generated from the fabricated microfluidic device.

A nanocomposite prepared from platinum particles, polyaniline and a TiC MXene for amperometric sensing of hydrogen peroxide and lactate.

A nanocomposite consisting of platinum particles, polyaniline and TiC MXene (Pt/PANI/MXene) was used to modify a screen-printed carbon electrode (SPCE) to obtain sensors for hydrogen peroxide and lactate. This nanocomposite was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) to determine the physical morphologies and the nanocomposite elements. The modified electrode exhibited the improved current response towards hydrogen peroxide (HO) compared with an unmodified electrode and provided a low detection limit of 1.