A comparative electrochemical study of non-enzymatic glucose, ascorbic acid, and albumin detection by using a ternary mesoporous metal oxide (ZrO(2), SiO(2) and In(2)O(3)) modified graphene composite based biosensor

In this study, we present an electrochemical investigation of a ternary mesoporous metal oxide (ZrO(2), SiO(2) and In(2)O(3)) modified graphene composite for non-enzymatic glucose, ascorbic acid, and albumin detection in urine at physiological pH. Synergetic property of ZrO(2)–Ag–G–SiO(2) and In(2)O(3)–G–SiO(2) were investigated via cyclic voltammetry (CV) using FTO glass and copper-foil electrodes with no prerequisite of solid antacid expansion. The mesoporous ZrO(2)–Ag–G–SiO(2) and In(2)O(3)–G–SiO(2) composites were synthesized and characterized using XRD, SEM, TEM, Raman spectroscopy, XPS, DRS, BET, and photocurrent measurements. Upon increasing the glucose concentration from 0 to 3 mM, CV results indicated two anodic peaks at +0.18 V and +0.42 V versus Ag/AgCl, corresponding to Zr(3+) and Zr(4+), respectively, considering the presence of glucose in urine. Moreover, the effects of high surface area In(2)O(3)–G–SiO(2) were observed upon the examination of ZrO(2)–Ag–G–SiO(2). In(2)O(3)–G–SiO(2) demonstrated a decent electrochemical pattern in glucose, ascorbic acid, and albumin sensing. Nevertheless, insignificant synergistic effects were observed in In(2)O(3)-G, ZrO(2)-G, and ZrO(2)–G–SiO(2). In(2)O(3)–G–SiO(2) performed well under a wide range of electrolytes and urine, and showed no activity toward uric acid, suggesting potential for biodetection in urine.