A non-enzymatic nanoceria electrode for non-invasive glucose monitoring

Abstract

Nanoceria (CeO₂) is a special rare earth material, which has electron transfer and catalytic ability. In this paper, an electrochemical method is used to combine CeO₂ and gold nanoparticles (AuNPs) on a glassy carbon electrode. It is shown that this combination can construct a catalyst–electron transfer system. The synergistic effect between CeO₂ and AuNPs can enable the system to mimic the enzyme–electron transfer function of glucose oxidase and increase the electron transfer rate, which can significantly increase the sensitivity and hence measure the glucose concentration through an electrochemical method. The system demonstrates a high sensitivity of 1071.52 μA mM⁻¹ cm⁻², and a detection limit of 2.86 × 10⁻³ mM (S/N = 3) across a linear range of 0.02–0.6 mM. Moreover, with a relatively low electrochemical surface area (ESA), the sensor demonstrates good stability, reproducibility, and anti-interference performance toward ascorbic acid (AA), uric acid (UA), and NaCl. The electrode therefore may be used to monitor the glucose level in human fluids, such as saliva and tears.