Given the importance of glucose monitoring in diabetes management, numerous methods have been developed for glucose monitoring. Many of these methods are invasive, causing discomfort, pain, and increasing the risk of infection. Therefore, the primary objective of this research is to develop a wearable, microfluidic glucose sensor powered by a fuel cell that aims to non-invasively monitor glucose levels and generate energy from sweat fluid with a pH of 6. In this regard, carbon electrodes were modified with gold nanoparticles and Mxene-platinum nanosheets to act as the anode and cathode of the biosensor, respectively. To synthesize Mxene-platinum, MXene nanosheets were first synthesized from the MAX phase Ti3AlC2Tx using the selective etching of aluminum in a solution containing hydrochloric acid and lithium fluoride. Analysis of the XRD results of Mxene showed a decrease in peak intensity at 2θ = 40, indicating the removal of aluminum from the MXene structure. Also, the shift of the peak from 2θ = 10 to 2θ = 6.5 indicates an increase in the interlayer spacing and the formation of multilayer Mxene. After confirming the structure and morphology of MXene nanosheets by XRD and FE-SEM analyses, platinum nanoparticles were deposited on the surface of MXene by a spontaneous reduction method, forming Mxene-platinum nanostructures and modifying the surface of the cathode electrode. To modify the surface of the anode electrode, gold nanoparticles were synthesized by two methods: chemical reduction with sodium citrate and electrodeposition. Cyclic voltammetry results for gold nanoparticles synthesized via electrodeposition using 1 mM chloroauric acid solution exhibited an oxidation peak current of 37 μA. This value was measured as 27 μA in the chemical reduction method with sodium citrate. Therefore, gold nanoparticles prepared by electrodeposition were used to modify the surface of the anode electrode. After modifying the surface of the anode and cathode electrodes, the performance of the fabricated biosensor was investigated in phosphate buffer solutions with pH = 7.5 and artificial sweat with pH = 6 containing glucose concentrations of 0 to 5 mM by linear sweep voltammetry (LSV). By plotting the power density curves at each concentration and determining the maximum power density, calibration curves were plotted for phosphate buffer and artificial sweat, and by calculating the slope of the calibration curve, the sensor sensitivity was 0.05 μW/cm²/mM in phosphate buffer and 0.04 μW/cm²/mM in artificial sweat. The sensor showed good selectivity in artificial sweat solution containing 1 mM glucose in the presence of interfering species compared to phosphate buffer containing 1 mM glucose at pH = 7.5 and showed reproducibility and repeatability of 92% and 94%, respectively. In the microfluidic section, a microfluidic reservoir with different numbers of inlets (6, 8, 10, 12, and 14), were simulated using COMSOL Multiphysics to eva‎luate the effect of the number of inlets on refresh time.Then, the microfluidic reservoir with 10 inputs, which had a refresh time of 155 seconds to reach 90% of the new solute concentration, was selected as the best option and fabricated by the molding method. The results of this study can be used in the development of self-powered and non-enzymatic sensors for non-invasive diagnosis of diseases.

فتح اله كريم زاده , محمدحسن عباسي

عليرضا صنعتي

مهران نحوي , شيدا لباف