Department of Chemistry, Capital Normal University, Beijing 100048, China.
Biosens Bioelectron. 2011 Feb 15;26(6):3068-71. doi: 10.1016/j.bios.2010.11.048. Epub 2010 Dec 5.
A label-free immunosensor was developed to detect the presence of an antigen. This immunosensor was based on the modulation of the electrochemistry of the surface bound redox species K(3)Fe(CN)(6) (FC). The model antigen was carcinoembryonic antigen (CEA) and the model epitope was the antibody of CEA (anti-CEA). Glassy carbon (GC) electrode surfaces were first drop-coated with a mixture of FC and chitosan and air-dried. The electrode surface was then covered with nafion membrane, which contained gold nanoparticles. After binding with polyethyleneimine (PEI), glutaraldehyde (GA) was used to cross-link PEI and anti-CEA. Binding of CEA to the surface bound epitope resulted in attenuation of the FC electrochemistry. Under optimal conditions, the response of the label-free immunosensor had a linear range of 0.01-150 ng mL(-1) with a detection limit of 3 pg mL(-1) (S/N = 3). Its response was better than those of radioimmunoassays, enzyme-linked immunosorbent assays, and chemiluminescence assays.
一种无标记免疫传感器被开发出来用于检测抗原的存在。该免疫传感器基于表面结合的氧化还原物质 K(3)Fe(CN)(6)（FC）电化学的调制。模型抗原是癌胚抗原（CEA），模型表位是 CEA 的抗体（抗-CEA）。玻碳（GC）电极表面首先用 FC 和壳聚糖的混合物滴涂，然后空气干燥。电极表面然后覆盖有包含金纳米粒子的纳滤膜。与聚乙烯亚胺（PEI）结合后，戊二醛（GA）用于交联 PEI 和抗-CEA。CEA 与表面结合的表位结合导致 FC 电化学的衰减。在最佳条件下，无标记免疫传感器的响应具有 0.01-150ng mL(-1)的线性范围，检测限为 3pg mL(-1)（S/N = 3）。其响应优于放射免疫分析、酶联免疫吸附分析和化学发光分析。
