Cerium Oxide/Polypyrrole Nanocomposite as the Matrix for Cholesterol Biosensor

A nanocomposite comprising cerium oxide nanoparticles (CeO2 NPs) and polypyrrole (PPy) was fabricated onto a microelectrode for cholesterol sensing application. The cholesterol oxidase (ChOx) was immobilized on the CeO2 NPs/PPy/electrode by the physical adsorption route. The structure and morphology of the CeO2 NPs/PPy nanocomposite were characterized by X-ray diffraction, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. Results showed that the ChOx/CeO2 NPs/PPy/electrode was linearly related with cholesterol in the range of 50 to 500 mg/dL. The sensitivity of ChOx/CeO2 NPs/PPy/electrode was 5.7x10(-6) mA/mg.dL(-1). The optimal parameters, including pH value and temperature, and selectivity, storage stability, and reproducibility of ChOx/CeO2 NPs/PPy/electrode were investigated.

Automated summary

A nanocomposite consisting of CeO2 NPs and PPy was successfully fabricated onto a microelectrode for cholesterol sensing application. The immobilization of ChOx on the CeO2 NPs/PPy/electrode was characterized, showing a linear relationship with cholesterol and a sensitivity of 5.7x10(-6) mA/mg.dL(-1). Optimal parameters, selectivity, storage stability, and reproducibility of the ChOx/CeO2 NPs/PPy/electrode were also investigated in the study.