This work presents a dual-quenching electrochemiluminescence resonance energy transfer (ECL-RET) immunosensor on account of the double quenching effects of polydopamine coated ZnO nanoflowers (ZnONFs@PDA) loaded with small-sized copper oxide nanoparticles (sCuO), named ZnONFs@PDA-sCuO, towards gold dendrite@polypyrrole core–shell nanoparticles (AuD@PPy) enhanced g-C₃N₄ (g-C₃N₄-AuD@PPy) for sensitive analysis of procalcitonin (PCT). To be specific, AuD@PPy with core-shell structure were loaded onto g-C₃N₄ to enhance the emission performance of g-C₃N₄. In addition, the ultraviolet absorption spectra of ZnONFs@PDA and sCuO showed considerable overlap with the ECL emission spectra of g-C₃N₄ appropriately. So sCuO and ZnONFs@PDA were combined and designed as an efficient dual-quencher of ECL luminescence of g-C₃N₄ by RET interaction. The biosensor showed superior linear detection range from 0.00005 to 50 ng mL⁻¹, with a sensitive detection limit of 17.2 fg mL⁻¹ (S/N = 3). It is worthy to note that a new type ECL-RET couple made up of g-C₃N₄-AuD@PPy (donor) and ZnONFs@PDA-sCuO (acceptor) was developed to construct a sandwich ECL biosensor for PCT detection. The studied immunosensor had satisfactory sensitivity, specificity and reproducibility, indicating the proposed sensing method could provide a good technical means and theoretical basis for the diagnosis of serious diseases.

本工作基于负载有小尺寸氧化铜纳米粒子 (sCuO) 的聚多巴胺涂层 ZnO 纳米花 (ZnONFs@PDA) 的双猝灭效应，提出了一种双猝灭电化学发光共振能量转移 (ECL-RET) 免疫传感器，命名为 ZnONFs@PDA -sCuO，对金枝晶@聚吡咯核壳纳米粒子 (AuD@PPy) 增强 gC ₃ N ₄ (gC ₃ N ₄ -AuD@PPy)，用于对降钙素原 (PCT) 进行灵敏分析。具体而言，将具有核壳结构的AuD@PPy负载到gC ₃ N ₄上以增强gC ₃ N _{4的发射性能}. 此外，ZnONFs@PDA和sCuO的紫外吸收光谱与gC ₃ N ₄的ECL发射光谱有相当大的重叠。因此，将sCuO和ZnONFs@PDA结合起来，设计为通过RET相互作用实现gC ₃ N ₄ ECL发光的高效双猝灭剂。该生物传感器显示出优异的线性检测范围，从 0.00005 到 50 ng mL ^-1，灵敏检测限为 17.2 fg mL ^-1 (S/N = 3)。值得注意的是，由 gC ₃ N _{4组成的新型 ECL-RET 对}-AuD@PPy（供体）和ZnONFs@PDA-sCuO（受体）被开发用于构建用于PCT检测的夹层ECL生物传感器。所研究的免疫传感器具有良好的灵敏度、特异性和重现性，表明所提出的传感方法可为严重疾病的诊断提供良好的技术手段和理论基础。