Key Laboratory of Applied Organic Chemistry (College of Jiangxi Province), Department of Chemistry, Shangrao Normal University, Shangrao 334001, Jiangxi, PR China.
Institute of Environmental and Analytical Science, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, PR China.
Anal Chim Acta. 2017 Aug 1;979:24-30. doi: 10.1016/j.aca.2017.05.014. Epub 2017 May 29.
A new magneto-controlled electrochemical immunosensing system was developed for the sensitive detection of low-abundance protein (IgG1 used in this case) with a sandwich-type assay format on monoclonal mouse anti-human F-specific IgG1-functionalized magnetic bead. Metal sulfide (CdS) quantum dot-doped bovine serum albumin (QD-BSA) was synthesized and functionalized with monoclonal F-specific anti-human antibody. In the presence of IgG1, the immobilized antibody on magnetic bead was selective to capture the F region of the analyte, followed to be sandwiched by the conjugated antibody onto QD-BSA. The subsequent anodic stripping voltammetric analysis of cadmium ion, released by acid from quantum dot, was conducted at an in situ prepared mercury film electrode. Under optimal conditions, the voltammetric current increased with the increasing of target IgG1 within a dynamic working range from 10 pg mL to 100 ng mL. The limit of detection of this immunosensor was evaluated to 3.4 pg mL at 3s criterion. The precision, selectivity and method accuracy were acceptable. Analysis of human serum samples revealed good accordance with the results obtained by commercial enzyme-linked immunosorbent assay method. Importantly, this concept offers promise for cost-effective analysis of low-abundance cancer biomarkers without the need of natural enzymes.
一种新的磁控电化学免疫传感系统被开发出来，用于在单克隆鼠抗人 F 特异性 IgG1 功能化的磁性珠上的三明治型测定形式下，对低丰度蛋白质（在这种情况下使用 IgG1）进行灵敏检测。金属硫化物（CdS）量子点掺杂牛血清白蛋白（QD-BSA）被合成并功能化有单克隆 F 特异性抗人抗体。在 IgG1 的存在下，固定在磁性珠上的抗体选择性地捕获分析物的 F 区，然后被缀合的抗体夹在 QD-BSA 之间。随后，通过量子点中的酸释放的镉离子的阳极溶出伏安分析在原位制备的汞膜电极上进行。在最佳条件下，随着目标 IgG1 的增加，伏安电流在 10 pg mL 至 100 ng mL 的动态工作范围内增加。该免疫传感器的检测限在 3s 标准下评估为 3.4 pg mL。该方法的精密度、选择性和准确度均令人满意。对人血清样本的分析显示与商业酶联免疫吸附测定方法的结果具有良好的一致性。重要的是，该概念为无需天然酶的情况下，对低丰度癌症生物标志物进行经济高效的分析提供了可能。
