Shi Gui-Fang, Cao Jun-Tao, Zhang Jing-Jing, Huang Ke-Jing, Liu Yan-Ming, Chen Yong-Hong, Ren Shu-Wei
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
Analyst. 2014 Nov 21;139(22):5827-34. doi: 10.1039/c4an01311e.
A facile label-free electrochemiluminescence (ECL) aptasensor, based on the ECL of cadmium sulfide-graphene (CdS-GR) nanocomposites with peroxydisulfate as the coreactant, was designed for the detection of carcinoembryonic antigen (CEA). Tripetalous CdS-GR nanocomposites were synthesized through a simple onepot solvothermal method and immobilized on the glassy carbon electrode surface. L-Cystine (L-cys) could largely promote the electron transfer and enhance the ECL intensity. Gold nanoparticles (AuNPs) were assembled onto the L-cys film modified electrode for aptamer immobilization and ECL signal amplification. The aptamer modified with thiol was adsorbed onto the surface of the AuNPs through a Au-S bond. Upon hybridization of the aptamer with the target protein, the sequence could conjugate CEA to form a Y architecture. With CEA as a model analyte, the decreased ECL intensity is proportional to the CEA concentration in the range of 0.01-10.0 ng mL(-1) with a detection limit of 3.8 pg mL(-1) (S/N = 3). The prepared aptasensor was applied to the determination of CEA in human serum samples. The recoveries of CEA in the human serum samples were between 85.0% and 109.5%, and the RSD values were no more than 3.4%.
基于硫化镉-石墨烯（CdS-GR）纳米复合材料与过二硫酸盐作为共反应剂的电化学发光（ECL），设计了一种简便的无标记ECL适体传感器，用于检测癌胚抗原（CEA）。通过简单的一锅溶剂热法合成了三叶状CdS-GR纳米复合材料，并将其固定在玻碳电极表面。L-胱氨酸（L-cys）可以极大地促进电子转移并增强ECL强度。将金纳米颗粒（AuNPs）组装到L-cys膜修饰电极上用于适体固定和ECL信号放大。用硫醇修饰的适体通过Au-S键吸附在AuNPs表面。当适体与目标蛋白杂交时，该序列可以结合CEA形成Y型结构。以CEA作为模型分析物，在0.01-10.0 ng mL(-1)范围内，ECL强度的降低与CEA浓度成正比，检测限为3.8 pg mL(-1)（S/N = 3）。将制备的适体传感器应用于人血清样品中CEA的测定。人血清样品中CEA的回收率在85.0%至109.5%之间，相对标准偏差（RSD）值不超过3.4%。
