In this paper, a label-free electrochemical immunosensor for sensitive detection of prostate antigen (PSA) was developed based on a NiFe PBA/AuNPs composite. The prostate antigen antibody was immobilized and the immunosensor was constructed by using a glassy carbon electrode modified with a nanocomposite consisting of nickel–iron Prussian blue analog (NiFe PBA) and gold nanoparticles (AuNPs). Due to the good biological affinity of AuNPs for biomolecules, as well as the porous nanostructure and regular shape of NiFe PBA, NiFe PBA/AuNPs nanocomposites significantly improve the electron transport rate, while achieving excellent performance for the sensor. Due to the interaction between the antibody and the antigen on the modified electrode, the current signal of the NiFe PBA itself is reduced due to the redox changes in Fe²⁺ and Fe³⁺, which can be determined by differential pulse voltammetry (DPV). Therefore, the monitoring of prostate antigen detection is realized. Under optimal experimental conditions, the immunosensor exhibited excellent detection performance with a dynamic response range from 0.5 pg mL⁻¹ to 1000 pg mL⁻¹ for the PSA concentration and a detection limit of 0.23 pg mL⁻¹ (S/N = 3). In addition, the PSA aptasensor has good selectivity, high stability, and satisfactory reproducibility and has broad potential in clinical research and diagnostic applications.

中文翻译：

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用于电化学检测 PSA 的 NiFe PBA/AuNPs 纳米复合敏感免疫传感器

本文开发了一种基于 NiFe PBA/AuNPs 复合材料的无标记电化学免疫传感器，用于灵敏检测前列腺抗原（PSA）。固定前列腺抗原抗体，并使用由镍铁普鲁士蓝类似物（NiFe PBA）和金纳米粒子（AuNPs）组成的纳米复合材料修饰的玻碳电极构建免疫传感器。由于AuNPs对生物分子良好的生物亲和力，以及NiFe PBA的多孔纳米结构和规则形状，NiFe PBA/AuNPs纳米复合材料显着提高了电子传输速率，同时实现了优异的传感器性能。由于修饰电极上抗体与抗原的相互作用，NiFe PBA本身的电流信号因Fe ²⁺和Fe ³⁺的氧化还原变化而降低，可以通过微分脉冲伏安法（DPV）测定。从而实现了前列腺抗原检测的监测。在最佳实验条件下，免疫传感器表现出优异的检测性能，PSA浓度的动态响应范围为0.5 pg mL ^-1至1000 pg mL ^{-1 ，检测限为0.23 pg mL -1} (S/N = 3)。此外，PSA适配体传感器具有良好的选择性、高稳定性和良好的重现性，在临床研究和诊断应用中具有广阔的潜力。