Department of Chemistry and Institute of BioPhysio Sensor Technology, Pusan National University, Pusan 609-735, South Korea.
Biosens Bioelectron. 2011 Jul 15;26(11):4429-35. doi: 10.1016/j.bios.2011.04.058. Epub 2011 May 6.
An ultrasensitive electrochemical immunosensor for a protein using a Ag (I)-cysteamine complex (Ag-Cys) as a label was fabricated. The low detection of a protein was based on the electrochemical stripping of Ag from the adsorbed Ag-Cys complex on the gold nanoparticles (AuNPs) conjugated human immunoglobulin G (anti-IgG) antibody (AuNPs-anti-IgG). The electrochemical immunosensor was fabricated by immobilizing anti-IgG antibody on a poly-5,2':5',2''-terthiophene-3'-carboxylic acid (polyTTCA) film grown on the glassy carbon electrode through the covalent bond formation between amine groups of anti-IgG and carboxylic acid groups of polyTTCA. The target protein, IgG was sandwiched between the anti-IgG antibody that covalently attached onto the polyTTCA layer and AuNPs-anti-IgG. Using square wave voltammetry, well defined Ag stripping voltammograms were obtained for the each target concentration. Various experimental parameters were optimized and interference effects from other proteins were checked out. The immunosensor exhibited a wide dynamic range with the detection limit of 0.4 ± 0.05 fg/mL. To evaluate the analytical reliability, the proposed immunosensor was applied to human IgG spiked serum samples and acceptable results were obtained indicating that the method can be readily extended to other bioaffinity assays of clinical or environmental significance.
采用 Ag（I）-半胱氨酸复合物（Ag-Cys）作为标记物，制备了一种用于蛋白质的超灵敏电化学免疫传感器。该蛋白质的低检测是基于在金纳米粒子（AuNPs）共轭人免疫球蛋白 G（抗-IgG）抗体（AuNPs-anti-IgG）上吸附的 Ag-Cys 复合物上电化学剥离 Ag。电化学免疫传感器是通过将抗-IgG 抗体固定在通过抗-IgG 上的胺基与聚 5,2'：5',2''-三联噻吩-3'-羧酸（polyTTCA）上的羧酸基之间的共价键形成在玻碳电极上生长的聚 TTCA 膜上来制备的。目标蛋白 IgG 夹在共价附着在 polyTTCA 层上的抗-IgG 抗体和 AuNPs-anti-IgG 之间。使用方波伏安法，针对每个目标浓度都获得了明确的 Ag 剥离伏安曲线。优化了各种实验参数，并检查了其他蛋白质的干扰效应。该免疫传感器具有较宽的动态范围，检测限为 0.4 ± 0.05 fg/mL。为了评估分析可靠性，将所提出的免疫传感器应用于人 IgG 加标血清样品，并获得了可接受的结果，表明该方法可以很容易地扩展到其他具有临床或环境意义的生物亲和力分析中。
