3D-Printed Flexible Conductive Hydrogel as a Wearable Platform for Dual Functions of Strain and Colorimetric Lactate Sensors.

Strain sensors have received considerable attention in personal healthcare due to their ability to monitor real-time human movement. However, the lack of chemical sensing capabilities in existing strain sensors limits their utility for continuous biometric monitoring. Although the development of dual wearable sensors capable of simultaneously monitoring human motion and biometric data presents significant challenges, the ability to fabricate these sensors with geometries tailored to individual users is highly desirable.

Cellulose nanocrystals from waste cotton fabric and polyvinyl alcohol composite hydrogel for non-invasive colorimetric sensing of cysteine.

Cellulose nanocrystals (CNCs) were successfully extracted and purified from cotton fabric waste via alkali treatment and acid hydrolysis. The resulting nanostructure was characterized using transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD), confirming the successful isolation of CNCs. A PV/Cu-CNCs/CNFs/PVA hydrogel was then synthesized through chemical crosslinking of polyvinyl alcohol (PVA), cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs), and borax.

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.

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.

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.

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.

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.

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.

Non-invasive textile based colorimetric sensor for the simultaneous detection of sweat pH and lactate.

A non-invasive textile-based colorimetric sensor for the simultaneous detection of sweat pH and lactate was created by depositing of three different layers onto a cotton fabric: 1.) chitosan, 2.) sodium carboxymethyl cellulose, and 3.