Wearable electrochemical glucose sensor of high flexibility and sensitivity using novel mushroom-like gold nanowires decorated bendable stainless steel wire sieve.

Long-term high blood glucose levels brings extremely detrimental effect on diabetic patients, such as blindness, renal failure, and cardiovascular diseases. Therefore, there is an urgent need to develop highly flexible and sensitive sensors for precisely non-invasive and continuous monitoring glucose levels. Herein, we present a highly flexible and sensitive wearable sensor for non-enzymatic electrochemical glucose analysis with vertically aligned mushroom-like gold nanowires (v-AuNWs) chemically grown on stainless steel wire sieve (SSWS) as integrated electrode. Owing to the unique nanostructures and excellent catalysis of the v-AuNWs, the as-fabricated glucose sensors exhibit superior flexibility and excellent electro-catalytic capability. In detail, these sensors display rapid response towards glucose within 5 s, and the sensor constructed with v-AuNWs for growth time of 15 min shows the highest sensitivity of 180.1 µA mM-1 cm-2 within a wide linear range of 6.5 × 10-4 mM-12.0 mM and the lowest detection limit of 0.65 µM (S/N = 3). It is noteworthy that due to the good ductility of the v-AuNWs and their strong contact with the SSWS substrate, these glucose sensors exhibit no obvious response variation after repeated bending for 100 times at bending angle of 180°. Additionally, the glucose sensors display superior anti-interfering capability as well as desirable repeatability. More importantly, these glucose sensors can be attached on human skin to determine sweat glucose reliably and analyze glucose concentration in human serum in vitro.

Investigation on the surface morphologies of reduced graphene oxide coating on the interfacial characteristics and electro-catalytic capacity of enzymatic glucose sensors.

In this study, reduced graphene oxide (rGO) were subject to ultrasonic treatment to acquire varied morphologies, and the enzymatic glucose sensors were constructed by coating the rGO onto indium tin oxide electrodes and physically linking glucose oxidase to the rGO coatings. The effects of the surface morphologies of the rGO coatings on the interfacial characteristics and the electro-catalytic capacity of the enzymatic glucose sensors were systematically investigated. It turns out that, the rGO coating with a rough surface is more hydrophilic, and exhibits uniform glucose oxidase adsorption and higher electron migration rate at the solid/liquid interface between the analytical liquid and the working electrode. As a result, the corresponding glucose sensor shows excellent electro-catalytic capacity towards glucose with a broader linear range of 0-10.0 mM, a higher sensitivity of 38.9µA·mM-1·cm-2, and a lower detection limit of 0.1µM (signal-to-noise ratio of 3). Additionally, the as-prepared glucose sensor exhibits excellent accuracy for detecting actual blood samples as well as superior resistance to interference from other substances (such as L-phenylalanine, urea, ascorbic acid, uric acid, NaCl, and KCl). These results establish the theoretical and experimental foundation for the application of rGO coating in the field of biosensors.