Development of glucose sensor based on cobalt and nickel doped ceria nanostructures

In this study, we report the development of a novel and effective electrochemical sensor for non-enzymatic glucose enhanced detection through Ni/Co doped ceria electrocatalysts instead of pristine ceria. The synthesized pristine and doped ceria nanostructures were characterized through X-ray diffraction, scanning electron microscopy and diffused reflectance spectroscopy (DRS). The electrochemical response of the ceria modified glassy carbon electrodes for the non-enzymatic detection of glucose was monitored through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry. Results indicate that Ni doped CeO2 and Co doped CeO2 show high sensitivity towards glucose in basic medium with sensitivity values of 11.1 µA/mM cm2 and 184 µA/mM cm2 respectively. The Ni/CeO2 and Co/CeO2 based sensor can detect glucose in a sample up to limits of 80 µM and 16 µM. The efficacy of the fabricated sensors is further demonstrated by EIS, where Co/CeO2 modified electrode shows much lower charge transfer resistance (Rct = 1107 Ω) compared to Ni/CeO2 modified GCE (Rct = 4337 Ω). Amperometric studies indicate a rapid response time (<10 s). The developed biosensors are also highly selective towards glucose amid various interfering species, including uric acid and ascorbic acid. Overall, the Co doped ceria nanostructures serve as efficient electrocatalyst for glucose due to greater electroactivity, high selectivity and sensitivity, low detection limit, and long-term stability.