He Xiulan, Yuan Ruo, Chai Yaqin, Shi Yintao
Chongqing Key Laboratory of Analytical Chemistry, Southwest University, Chongqing 400715, PR China.
J Biochem Biophys Methods. 2008 Apr 24;70(6):823-9. doi: 10.1016/j.jbbm.2007.06.002. Epub 2007 Jul 5.
A sensitive amperometric immunosensor for carcinoembryonic antigen (CEA) was prepared. Firstly, a porous nano-structure gold (NG) film was formed on glassy carbon electrode (GCE) by electrochemical reduction of HAuCl4 solution, then nano-Au/Chit composite was immobilized onto the electrode because of its excellent membrane-forming ability, and finally the anti-CEA was adsorbed onto the surface of the bilayer gold nanoparticles to construct an anti-CEA/nano-Au/Chit/NG/GCE immunosensor. The characteristics of the modified electrode at different stages of modification were studied by cyclic voltammetry (CV). The gold colloid, chitosan and nano-Au/Chit were characterized by transmission electron microscopy and UV-vis spectroscopy. In addition, the performances of the immunosensor were studied in detail. The resulting immunosensor offers a high-sensitivity (1310 nA/ng/ml) for the detection of CEA and has good correlation for detection of CEA in the range of 0.2 to 120.0 ng/ml with a detection limit of 0.06 ng/ml estimated at a signal-to-noise ratio of 3. The proposed method can detect the CEA through one-step immunoassay and would be valuable for clinical immunoassay.
制备了一种用于癌胚抗原（CEA）的灵敏安培免疫传感器。首先，通过对HAuCl4溶液进行电化学还原，在玻碳电极（GCE）上形成多孔纳米结构金（NG）膜，然后由于纳米金/壳聚糖复合材料具有优异的成膜能力，将其固定在电极上，最后将抗CEA吸附到双层金纳米颗粒表面，构建抗CEA/纳米金/壳聚糖/NG/GCE免疫传感器。通过循环伏安法（CV）研究了修饰电极在不同修饰阶段的特性。用透射电子显微镜和紫外可见光谱对金胶体、壳聚糖和纳米金/壳聚糖进行了表征。此外，还详细研究了该免疫传感器的性能。所得免疫传感器对CEA检测具有高灵敏度（1310 nA/ng/ml），在0.2至120.0 ng/ml范围内检测CEA具有良好的相关性，在信噪比为3时估计检测限为0.06 ng/ml。所提出的方法可通过一步免疫测定法检测CEA，对临床免疫测定具有重要价值。
