CuO nanoparticles decorated nano-dendrite-structured CuBi 2 O 4 for highly sensitive and selective electrochemical detection of glucose

Abstract In this study, a chemically modified electrode, consisting of CuO nanoparticles decorated nano-dendrite-structured CuBi2O4 (nanoCuBi2O4|CuO), was fabricated and its application as an electrocatalyst in catalyzing the oxidation of glucose was investigated. nanoCuBi2O4|CuO was fabricated by firstly electrodepositing BiOI nanosheet array (nanoBiOI) on the flourine-doped tin oxide coated glass substrate, followed by its conversion into nanoCuBi2O4|CuO via drop-casting an ethanolic Cu2+ solution and follow-up thermal treatment. The degree of conversion of nanoBiOI into nanoCuBi2O4|CuO and electrocatalytic activites of resultant nanoCuBi2O4|CuO were controlled by adjusting the dosage of the ethanolic Cu2+ precursor solution. Surface morphology, structure, crystal phase, chemical composition, and electrocatalytic properties of the nanoCuBi2O4|CuO were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. It was found that both CuO and CuBi2O4 are active in electrocatalyzing the oxidation of glucose, but the porous structure of nanoCuBi2O4|CuO along with the synergistic catalytic enhancement, exerted by CuBi2O4 and CuO, renders nanoCuBi2O4|CuO superior electrocatalytic activity than CuO or CuBi2O4 alone. The mechanism of electrocatalytic oxidation of glucose on nanoCuBi2O4|CuO is proposed. Finally, the sensing characteristics of nanoCuBi2O4|CuO was evaluated, and the results indicate nanoCuBi2O4|CuO is a promising sensing material for the electrochemical detection of glucose.