Thick-film electrochemical immunosensor based on stripping potentiometric detection of a metal ion label.
Thick-film electrochemical immunosensor based on stripping potentiometric detection of a metal ion label.
复制标题
DOI：
10.1021/ac971298n
复制
发表时间：
1998-03
影响因子：
7.4
通讯作者：
J. Wang;B. Tian;K. Rogers
中科院分区：
文献类型：
--
作者：
J. Wang;B. Tian;K. Rogers
展示了一种基于金属示踪剂电位剥离分析 (PSA) 并使用完全芯片上分析格式的一次性电化学免疫传感器。与早期溶出伏安免疫测定法适应片上操作以及满足分散测试的需求相关的挑战已经得到解决。其中包括抗体的表面固定、更换汞滴电极、消除分离和除氧步骤以及使用静态 30 微升样品液滴。使用人血清白蛋白（HSA）和抗HSA抗体作为模型系统，而铋离子作为金属标记。将抗 HSA 固定在厚膜电极的表面上，然后双标记分析物示踪剂和分析物 (HSA) 竞争抗体结合位点。去除未结合的示踪剂后，Bi3+ 被释放并被 PSA 检测到。 HSA 的动态浓度范围（0.3-30 微克/mL）和检测限（0.2 微克/mL，即 30 微升样品中的 90 fmol）表明大大简化的实验方案不会影响剥离免疫测定的性能特征。因此，这种片上操作为分散式（临床和环境）应用提供了广阔的前景。
A disposable electrochemical immunosensor based on potentiometric stripping analysis (PSA) of a metal tracer and using an entirely on-chip assay format is demonstrated. Challenges associated with the adaptation of earlier stripping voltammetric immunoassays to an on-chip operation, and with meeting the demands of decentralized testing, have been addressed. These include the surface immobilization of the antibody, the replacement of mercury drop electrodes, elimination of the separation and oxygen-removal steps, and the use of quiescent 30-microL sample droplets. Human serum albumin (HSA) and anti-HSA antibody were used as a model system, while bismuth ion served as the metal label. The anti-HSA was immobilized onto the surface of a thick-film electrode, followed by a competition between the Bi-labeled analyte-tracer and the analyte (HSA) for the antibody binding sites. Upon removal of the unbound tracer, Bi3+ was released and detected by PSA. The dynamic concentration range for HSA (0.3-30 micrograms/mL) and the detection limit (0.2 microgram/mL, i.e., 90 fmol in the 30-microL sample) indicate that the greatly simplified protocol does not compromise the performance characteristics of stripping immunoassays. Consequently, this on-chip operation offers great promise for decentralized (clinical and environmental) applications.