The Key Lab of Analytical Chemistry for Life Science (MOE), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
Biosens Bioelectron. 2011 Apr 15;26(8):3654-9. doi: 10.1016/j.bios.2011.02.023. Epub 2011 Feb 21.
A novel and simple method for preparing cadmium sulfide nanoparticles (CdS NPs) functionalized colloidal carbon particles (CPs) has been successfully developed by in situ growing abundant CdS NPs on the surfaces of monodisperse carbon particles (CdS/CPs). The obtained CdS/CPs conjugates as signal amplification labels were further used for the ultrasensitive determination of thrombin. The CdS/CPs conjugates were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visible absorption spectrum (UV). The protein electrical detection involves a dual binding event, based on thrombin linked to the CdS/CPs tags and glass surface by the specific aptamer-protein affinity interactions and a succedent electrochemical stripping transduction. Owing to the high-content CdS NPs on carbon particles, this assay allowed a desirable detection limit of 6.0 × 10(-17)M, which was 1000 times lower than that of only using CdS NPs as labels in the control experiments. This protocol exhibited excellent selectivity against these common proteins such as bovine plasma albumin, lysozyme and hemoglobin. The signal amplification approach proposed here provides a facile, cost-effective method for the ultrasensitive determination of thrombin in the practical samples.
一种新颖且简单的方法，用于制备硫化镉纳米粒子（CdS NPs）功能化胶体碳颗粒（CPs），通过在单分散碳颗粒（CdS/CPs）表面原位生长丰富的 CdS NPs 成功开发出来。所得的 CdS/CPs 缀合物作为信号放大标记物，进一步用于凝血酶的超灵敏测定。通过透射电子显微镜（TEM）、X 射线光电子能谱（XPS）和紫外可见吸收光谱（UV）对 CdS/CPs 缀合物进行了表征。蛋白质电检测涉及双重结合事件，基于凝血酶通过特定适体-蛋白质亲和力相互作用与 CdS/CPs 标签和玻璃表面连接，以及随后的电化学剥离转导。由于碳颗粒上高含量的 CdS NPs，该测定法允许达到 6.0×10(-17)M 的理想检测限，比仅在对照实验中使用 CdS NPs 作为标记物的检测限低 1000 倍。该方案对牛血清白蛋白、溶菌酶和血红蛋白等常见蛋白质表现出优异的选择性。这里提出的信号放大方法为实际样品中凝血酶的超灵敏测定提供了一种简便、经济有效的方法。
