A comparative electrochemical study of non-enzymatic glucose, ascorbic acid, and albumin detection by using a ternary mesoporous metal oxide (ZrO₂, SiO₂and In₂O₃) modified graphene composite based biosensor

Abstract

In this study, we present an electrochemical investigation of a ternary mesoporous metal oxide (ZrO₂, SiO₂ and In₂O₃) modified graphene composite for non-enzymatic glucose, ascorbic acid, and albumin detection in urine at physiological pH. Synergetic property of ZrO₂-Ag-G-SiO₂ and In₂O₃-G-SiO₂ were investigated <i>via</i> cyclic voltammetry (CV) using FTO glass and copper-foil electrodes with no prerequisite of solid antacid expansion. The mesoporous ZrO₂-Ag-G-SiO₂ and In₂O₃-G-SiO₂ 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 <i>versus</i> Ag/AgCl, corresponding to Zr³⁺ and Zr⁴⁺, respectively, considering the presence of glucose in urine. Moreover, the effects of high surface area In₂O₃-G-SiO₂ were observed upon the examination of ZrO₂-Ag-G-SiO₂. In₂O₃-G-SiO₂ demonstrated a decent electrochemical pattern in glucose, ascorbic acid, and albumin sensing. Nevertheless, insignificant synergistic effects were observed in In₂O₃-G, ZrO₂-G, and ZrO₂-G-SiO₂. In₂O₃-G-SiO₂ performed well under a wide range of electrolytes and urine, and showed no activity toward uric acid, suggesting potential for biodetection in urine.