Development of non-enzymatic amperometric glucose sensor based on carboxylated graphene oxide supported au nanoparticles

In our sudy, we have developed an enzyme-free glucose sensor based on Au nanoparticles (AuNPs) loaded on carboxylated graphene oxide (GO-COOH) for electrocatalytic determination of glucose. Glassy carbon electrode (GCE) was modified using GO-COOAu. The obtained GO-COOAu/GCE exhibited good sensitivity and stability toward electro-oxidation of glucose because of high surface area of GO-COOH support and excellent electron conductivity of AuNPs when compared with graphene oxide (GO). The surface morphology of the GO-COOH and GO-COOAu was investigated by means of X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM). The electrochemical characterization of the working electrodes was determined utilizing electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and amperometry. The sensor showed a sensitivity of 20.218 µA mM-1 cm-2 and a wide linear detection range of 0.02-4.58 mM (R2 = 0.9919) at + 0.35 V. The sensor displayed a limit of detection (LOD) of 6 µM. The selectivity, repeatability, reproducibility, response time, and storage stability of the sensor were seen to be satisfactory. Also, the sensor was used for quantification of glucose in human serum samples. The results indicated that the GO-COOAu/GCE sensor might be an alternative for detection of glucose.