Preparation of modified electrode by Ag nanoparticles in graphene oxide substrate and its application in glucose analysis in real samples

Due to the pivotal role of glucose in physiological processes, much effort has been devoted to the development of highly sensitive and selective, low cost and reliable methods for detecting glucose in food and biological matrices. Many electrochemical techniques have been developed to detect glucose [1-3]. A non-enzymatic glucose sensor based on pencil graphite electrode (PGE) modified by Ag nanoparticles decorated reduced graphene oxide (Ag(NP)/rGO-PGE) was prepared. The prepared Ag(NP)/rGO exhibited a nano porous structure by scanning electron microscopy (SEM). Cyclic voltammetry at Ag(NP)/rGO-PGE showed the immobilized Ag(NP)s were highly stable in alkaline solutions and had high electrocatalytic activity toward glucose oxidation. Using amperometry, the detection limit of [0.09 (±0.003) µM] and concentration sensitivity of [2295 (±3.2) µA mM-1cm-2] for glucose was obtained at optimum conditions. The applicability of the sensor was evaluated to determine the glucose concentration in real samples. The preparation of Ag(NP)/rGO-PGE was reproducible, very simple, fast and inexpensive for practical application.