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.