Monitoring the level of cholesterol in blood serum is a critical approach for diseases surveillance. In this work, we reported on the successful construction of a new electrochemiluminescence (ECL) sensor for cholesterol detection by employing the Ag-(bovine serum albumin) BSA-MnO₂ nanosheets for cholesterol oxidase (ChOx) immobilization and catalytic amplification of ECL signal. The AgNPs-BSA-MnO₂ nanosheets were synthesized by using BSA as protective agent, which greatly facilitated the immobilization of ChOx due to the existing amino group donated by BSA. The structure and properties of the AgNPs-BSA-MnO₂ nanosheets were characterized by a series of techniques, including transmission electron microscope (TEM), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Importantly, experiment results indicated that the synergistic effect of AgNPs with MnO₂ nanosheets could provide excellent catalytic ability towards ROSs generation and thus to efficiently amplify the ECL signal of luminol-H₂O₂ system. Under optimal conditions, the ECL intensity increased with the increasing cholesterol concentration in a dynamic range from 0.21 μM to 1667 μM with a limit of detection (LOD) of 0.07 μM (3σ).

监测血清中胆固醇的水平是疾病监测的关键方法。在这项工作中，我们报道了通过使用Ag-（牛血清白蛋白）BSA-MnO ₂纳米片固定胆固醇氧化酶（ChOx）和催化放大ECL信号，成功构建了一种用于胆固醇检测的新型电化学发光（ECL）传感器。以牛血清白蛋白（BSA）为保护剂合成了AgNPs-BSA-MnO ₂纳米片，由于牛血清白蛋白（BSA）提供的氨基存在，大大促进了ChOx的固定。AgNPs-BSA-MnO ₂的结构与性能纳米片通过一系列技术进行表征，包括透射电子显微镜（TEM），扫描电子显微镜（SEM），能量色散X射线光谱仪（EDS），粉末X射线衍射仪（XRD）和傅里叶变换红外光谱仪（ FT-IR）。重要的是，实验结果表明，AgNPs与MnO ₂纳米片的协同作用可以为ROSs的产生提供出色的催化能力，从而有效地放大luminol-H ₂ O ₂系统的ECL信号。在最佳条件下，ECL强度在0.21μM至1667μM的动态范围内随胆固醇浓度的增加而增加，检测限（LOD）为0.07μM（3σ）。