An electrochemical biosensor based on the antifouling zwitterionic peptide hydrogel (CFEFKFC) and the poly(3,4-ethylenedioxythiophene) (PEDOT) was fabricated to accurately detect prostate specific antigen (PSA) in complex human serum. The electrode was modified with the conducting polymer PEDOT and gold nanoparticles (AuNPs) in sequence through electrodeposition, and then the designed zwitterionic peptide hydrogel prepared through self-assembly was immobilized onto the modified electrode surface via the Au–S bond. The zwitterionic peptide hydrogel with cysteine terminal is easy for immobilization onto the gold surface, and it is also suitable for the immobilization of biomolecules such as PSA antibody in this work, through the formation of covalent amide bonds. The peptide hydrogel possessed excellent antifouling property, and it was able to effectively prevent the adsorption of nonspecific proteins, cells and other biomolecules. The developed antifouling biosensor showed a linear response range from 0.1 ng mL⁻¹ to 100 ng mL⁻¹, with a low limit of detection down to 5.6 pg mL⁻¹. These results encourage the wide use of zwitterionic peptide hydrogels as antifouling materials in various sensing and bio-sensing devices.

基于防污两性离子肽水凝胶 (CFEFKFC) 和聚 (3,4-乙烯二氧噻吩) (PEDOT) 的电化学生物传感器被制造用于准确检测复杂人血清中的前列腺特异性抗原 (PSA)。通过电沉积依次用导电聚合物PEDOT和金纳米粒子（AuNPs）对电极进行修饰，然后通过Au-S键将通过自组装制备的设计两性离子肽水凝胶固定到修饰的电极表面。具有半胱氨酸末端的两性离子肽水凝胶易于固定到金表面，通过形成共价酰胺键，也适用于本工作中 PSA 抗体等生物分子的固定。肽水凝胶具有优异的防污性能，并能有效阻止非特异性蛋白质、细胞等生物分子的吸附。开发的防污生物传感器显示线性响应范围从 0.1 ng mL^-1至 100 ng mL ^-1，检测下限低至 5.6 pg mL ^-1。这些结果促进了两性离子肽水凝胶在各种传感和生物传感设备中作为防污材料的广泛使用。