Based on the target-induced catalytic hairpin assembly and bimetallic catalyst, the enzyme-free recycling amplification strategy for sensitive detection of prostate specific antigen (PSA) has been designed. The aptamer and its complementary DNA (C-apt) are modified on the magnetic particles. The aptamer-PSA binding event can release the C-apt that triggers the catalytic assembly between hairpin capture DNA and hairpin help DNA. Then the catalytic hairpin assembly leads to cyclic reuse the C-apt and the generation of many opened hairpin capture DNA, which can associate with the prepared Au/Pt-polymethylene blue (PMB) probes to yield electrochemical signal. Meanwhile, the Au/Pt-PMB probes exhibit excellent electrocatalytic ability for H₂O₂ to magnify the response current. The designed sensor possesses a wide dynamic range of 10 fg mL⁻¹ to 100 ng mL⁻¹ and ultra-low detection limit of 2.3 fg mL⁻¹. The present method has good performance in real serum sample analysis. This strategy is promising to be extended to provide a highly sensitive platform for various target analytes.

基于目标诱导的催化发夹装配和双金属催化剂，设计了用于灵敏检测前列腺特异抗原（PSA）的无酶循环扩增策略。适体及其互补DNA（C-apt）在磁性颗粒上被修饰。适体-PSA结合事件可以释放C-apt，从而触发发夹捕获DNA和发夹帮助DNA之间的催化组装。然后，催化发夹装配导致C-apt的循环再利用以及许多开放的发夹捕获DNA的产生，这些DNA可与制备的Au / Pt-聚亚甲基蓝（PMB）探针结合以产生电化学信号。同时，Au / Pt-PMB探针对H ₂ O ₂表现出优异的电催化能力。放大响应电流。设计的传感器具有10 fg mL ^-1至100 ng mL ^-1的宽动态范围和2.3 fg mL ^-1的超低检测限。本方法在实际血清样品分析中具有良好的性能。该策略有望扩展以为各种目标分析物提供高度敏感的平台。