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  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.

中文翻译：

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氧化铈/聚吡咯纳米复合材料作为胆固醇生物传感器的基质

将包含二氧化铈纳米颗粒（CeO ₂ NPs）和聚吡咯（PPy）的纳米复合材料制作到微电极上，以进行胆固醇传感。胆固醇氧化酶（ChOx）通过物理吸附途径固定在CeO ₂ NPs / PPy /电极上。通过X射线衍射，场发射扫描电子显微镜和能量色散X射线光谱对CeO ₂ NPs / PPy纳米复合材料的结构和形貌进行了表征。结果表明，在50至500 mg / dL范围内，ChOx / CeO ₂ NPs / PPy /电极与胆固醇呈线性关系。ChOx / CeO ₂ NPs / PPy /电极的灵敏度为 mA / mg·dL ^-1。研究了最佳的参数，包括pH值和温度，ChOx / CeO ₂ NPs / PPy /电极的选择性，储存稳定性和重现性。