In this work, we fabricated a novel sandwich-type electrochemical immunosensor for quantitative and ultra-sensitive determination of tumor suppressor protein p53 by signal amplification strategy. Conductive polymers poly (3, 4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS) has significantly effect on enhancing charge transfer and markedly increases the sensitivity of electrochemical immunosensing. Gold nanoparticles (AuNPs) as high conductivity nanocarriers were also used to capture monoclonal antibodies (Ab₁) due to their large specific surface areas. In addition, pH responsive zeolitic imidazolate framework (ZIF-8) was used to load the redox probe 2, 3-diaminophenazine (DAP) and the secondary antibodies (Ab₂) to form a sensitive-type ZIF-8–DAP–Ab₂ immunoprobe. After the sandwich-type immunoassay with the free p53 protein, with the release of probe DAP after the electrochemical signal amplificated by PEDOT:PSS and AuNPs, the ultra-sensitive and quantitative determination of p53 protein was realized with working range of 1–120 ng mL⁻¹ and low detection limit of 0.09 ng mL⁻¹. Besides, the fabricated electrochemical immunosensor exhibited good recovery, high sensitivity, reliability, and selectivity.

在这项工作中，我们制造了一种新型的夹心型电化学免疫传感器，用于通过信号放大策略定量和超灵敏地测定肿瘤抑制蛋白p53。导电聚合物聚（3，4-乙撑二氧噻吩）：聚苯乙烯磺酸盐（PEDOT：PSS）对增强电荷转移具有显著作用，并显着提高了电化学免疫传感的灵敏度。由于高比表面积，金纳米颗粒（AuNPs）作为高电导率纳米载体也被用于捕获单克隆抗体（Ab ₁）。此外，使用pH响应型沸石咪唑酸盐骨架（ZIF-8）加载氧化还原探针2、3-二氨基吩嗪（DAP）和第二抗体（Ab ₂），以形成敏感型ZIF-8–DAP–Ab ₂免疫探针。用游离p53蛋白进行夹心型免疫分析后，通过PEDOT：PSS和AuNPs放大电化学信号后释放探针DAP，实现了p53蛋白的超灵敏定量测定，工作范围为1-120 ng mL ^-1和0.09 ng mL ^-1的低检测限。此外，所制备的电化学免疫传感器具有良好的回收率，高灵敏度，可靠性和选择性。