Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Talanta. 2013 May 15;109:167-72. doi: 10.1016/j.talanta.2013.02.002. Epub 2013 Feb 18.
A new electrochemical biosensor with enhanced sensitivity was developed for detection of cholesterol by using platinum-palladium-chitosan-graphene hybrid nanocomposites (PtPd-CS-GS) functionalized glassy carbon electrode (GCE). An electrodeposition method was applied to form PtPd nanoparticles-doped chitosan-graphene hybrid nanocomposites (PtPd-CS-GS), which were characterized by scanning electron microscopy (SEM) and electrochemical methods. The presence of the PtPd-CS-GS nanocomposites not only accelerated direct electron transfer from the redox enzyme to the electrode surface, but also enhanced the immobilized amount of cholesterol oxidase (ChOx). Under optimal conditions, the fabricated biosensor exhibited wide linear ranges of responses to cholesterol in the concentration ranges of 2.2×10(-6) to 5.2×10(-4)M, the limit of detection was 0.75 μM (S/N=3). The response time was less than 7s and the Michaelis-Menten constant (Km(app)) was found as 0.11 mM. In addition, the biosensor also exhibited excellent reproducibility and stability. Along with these attractive features, the biosensor also displayed very high specificity to cholesterol with complete elimination of interference from UA, AA, and glucose.
一种新的电化学生物传感器，通过使用铂钯壳聚糖-石墨烯杂化纳米复合材料（PtPd-CS-GS）功能化玻碳电极（GCE），提高了检测胆固醇的灵敏度。采用电化学沉积法形成 PtPd 纳米粒子掺杂壳聚糖-石墨烯杂化纳米复合材料（PtPd-CS-GS），通过扫描电子显微镜（SEM）和电化学方法对其进行了表征。PtPd-CS-GS 纳米复合材料的存在不仅加速了氧化还原酶与电极表面之间的直接电子转移，而且还增强了胆固醇氧化酶（ChOx）的固定量。在最佳条件下，所制备的生物传感器对胆固醇在 2.2×10(-6)至 5.2×10(-4)M 的浓度范围内表现出宽线性响应范围，检测限为 0.75 μM（S/N=3）。响应时间小于 7s，米氏常数（Km(app)）为 0.11 mM。此外，该生物传感器还表现出出色的重现性和稳定性。除了这些吸引人的特点外，该生物传感器对胆固醇还具有非常高的特异性，完全消除了 UA、AA 和葡萄糖的干扰。
