Abstract A label-free electrochemical inmunosensor based on specific antibody immobilization was developed attached to an aminophenylboronic/poly-indole-6-carboxylic acid-modified electrode (APBA/6-PICA/GCE) for detection of the cancer biomarker, prostate-specific antigen (PSA). The optimal conditions for developing a reproducible bioplatform with excellent stability were determined, focusing on time and incubation temperature. Guided antibody immobilization was carried out using APBA and shown to improve the antigen-antibody affinity. Following the intrinsic redox response of 6-PICA, which corresponds to the electrode doping-undoping charge transfer process, this was chosen as an analytical electrochemical signal using square wave voltammetry (SWV). Cyclic voltammetry, electrochemical impedance spectroscopy and SWV were used in the characterization in the step-by-step optimal construction of the immunosensor and PSA detection. The calibration curve shows a linear range between 0.50 and 100.0 ng·mL−1, with a limit of detection (LOD) of 0.11 ng·mL−1, and a limit of quantification (LOQ) of 0.33 ng·mL−1, respectively. Also, an affinity constant (Ka) between specific monoclonal antibody and PSA was determined at 6.37·109 M−1. These analytical quality parameters propose that the bioplatform can be used to detect PSA concentrations within clinically relevant levels.

中文翻译：

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导电聚合物应用于无标记电化学免疫传感器中，以氧化还原反应作为分析信号检测前列腺特异性抗原

摘要 开发了一种基于特异性抗体固定化的无标记电化学免疫传感器，连接到氨基苯基硼酸/聚吲哚-6-羧酸修饰电极 (APBA/6-PICA/GCE) 上，用于检测癌症生物标志物、前列腺特异性抗原。 (PSA)。确定了开发具有优异稳定性的可重现生物平台的最佳条件，重点是时间和孵育温度。使用 APBA 进行了引导抗体固定，结果表明可以提高抗原抗体亲和力。根据 6-PICA 的固有氧化还原响应，这对应于电极掺杂-去掺杂电荷转移过程，这被选为使用方波伏安法 (SWV) 的分析电化学信号。循环伏安法，电化学阻抗谱和 SWV 用于表征分步优化构建免疫传感器和 PSA 检测。校准曲线显示线性范围介于 0.50 和 100.0 ng·mL-1 之间，检测限 (LOD) 为 0.11 ng·mL-1，定量限 (LOQ) 分别为 0.33 ng·mL-1 . 此外，特定单克隆抗体和 PSA 之间的亲和常数 (Ka) 确定为 6.37·109 M-1。这些分析质量参数表明，该生物平台可用于检测临床相关水平内的 PSA 浓度。分别。此外，特定单克隆抗体和 PSA 之间的亲和常数 (Ka) 确定为 6.37·109 M-1。这些分析质量参数表明，该生物平台可用于检测临床相关水平内的 PSA 浓度。分别。此外，特定单克隆抗体和 PSA 之间的亲和常数 (Ka) 确定为 6.37·109 M-1。这些分析质量参数表明，该生物平台可用于检测临床相关水平内的 PSA 浓度。