This work describes a sensitive voltammetric immunosensor for label‐free electroanalysis of the prostate specific antigen (PSA), the main biomarker of prostate cancer. A gold electrode was firstly modified with the optimum self‐assembled monolayer (SAM), 1,6‐hexanedithiol, followed by the subsequent adsorption of gold nanoparticles (AuNPs) and, then, the monoclonal antibody to recognize PSA was immobilized. The influence of the most significant experimental variables (SAM type and incubation time, AuNPs deposition, antibody concentration and bovine serum albumin immobilization) on the biosensor response was studied by microscopy and voltammetry techniques. The electroanalytical detection was based on the interaction between PSA antibody and PSA via square‐wave voltammetry using ferrocyanide/ferricyanide as electrochemical redox indicator. Using the proposed immunosensor, PSA was specifically detected within the linear range between 0.2 and 200 ng mL⁻¹ with 0.01 ng mL⁻¹ as limit of detection. The immunosensor allows accurate, reproducible and sensitive (22.7 % reduction mL ng⁻¹) detection in a concentration range useful for clinical purposes.

中文翻译：

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用于前列腺特异性抗原检测的无标记伏安免疫传感器

这项工作描述了一种灵敏的伏安免疫传感器，可对前列腺癌的主要生物标志物前列腺特异性抗原（PSA）进行无标记的电分析。首先用最佳的自组装单分子膜（SAM）1,6-己二硫醇修饰金电极，然后吸附金纳米颗粒（AuNPs），然后固定识别PSA的单克隆抗体。通过显微镜和伏安法研究了最重要的实验变量（SAM类型和孵育时间，AuNPs沉积，抗体浓度和牛血清白蛋白固定化）对生物传感器响应的影响。电分析检测是基于PSA抗体和PSA之间的相互作用通过使用亚铁氰化物/铁氰化物作为电化学氧化还原指示剂的方波伏安法 使用所提出的免疫传感器，以0.01ngmL ^-1作为检测极限，在0.2至200ngmL ^-1的线性范围内特异性地检测了PSA 。免疫传感器可在可用于临床目的的浓度范围内进行准确，可再现和灵敏的检测（降低浓度达22.7％mL ng ^-1）。