Electrochemical deposition of silver/silver oxide on reduced graphene oxide for glucose sensing

Graphene oxide (GO) was synthesized by modified Hummer’s method and converted to reduced graphene oxide (rGO) by chemical method. GO and rGO were decorated with silver/silver oxide (Ag/Ag2O-GO and Ag/Ag2O-rGO) by electrochemical method without using any stabilizing agent. Structural and physiochemical properties of the products were investigated with the help of ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and scanning electron microscope (SEM) images. Energy dispersive X-ray (EDX) analysis and XRD confirmed the deposition of silver and silver oxide on the GO and rGO. Further, Ag/Ag2O-rGO was applied for amperometric sensing of glucose in alkaline solution due to the presence of a thin layer of silver on the surface of rGO. Current-time dynamic response at + 0.60 V step potential vs. Hg/HgO in NaOH (0.1 M) were recorded, and linear response was obtained (R2 = 0.991) as a function of glucose concentration (0.2–8 mM), with a detection limit of 0.060 mM (S/N ratio 3) and sensitivity of 32 μAmM−1 cm−2. The signal corresponding to glucose was not seen to be affected due to interference from ascorbic acid, uric acid, and chloride ions present in the solution.