Abstract Salmonella typhimurium (S. typhimurium) infection disease is harm to public through food have become a life-threatening problem stresses an urgent need for development of rapid, robust and cost-effective alternative technology to help control the spread of S. typhimurium. Herein, a simple and facile aptasensor has been developed for ultrasensitive determination of live S. typhimurium by combining target-induced aptamer displacement on gold nanoparticles (AuNPs) deposited electrode with rolling circle amplification (RCA). The heterogeneous recognition and specific binding of target S. typhimurium with aptamer, releasing the primer binding part, leading to anchoring multiple circular templates on the aptasensor surface. Then, the RCA reaction was initiated to produce massive long DNA molecules with multiple tandem-repeat sequences. These RCA products could hybridize with the biotinylated detection probes for enzyme-amplified electrochemical readout on the surface of the aptasensor. The designed electrochemical aptasensor showed very high sensitivity for S. typhimurium down to 16 CFU mL−1 with a wide linear detection range of 20 to 2 × 108 CFU mL−1, and exhibited remarkable signal amplification performance, acceptable reproducibility and low matrix effect. This proposed strategy presented a simple and facile platform towards ultrasensitive and handy bacterial detection, which would become an effective tool for microorganism detection in food safety, clinical diagnostics and even biological threats monitoring.

中文翻译：

---

金纳米颗粒上的靶诱导适体置换和滚环放大用于超灵敏活鼠伤寒沙门氏菌电化学生物传感

摘要 鼠伤寒沙门氏菌（S. typhimurium）感染疾病是通过食物危害公众已成为危及生命的问题，迫切需要开发快速、稳健和具有成本效益的替代技术来帮助控制鼠伤寒沙门氏菌的传播。在此，通过将金纳米粒子 (AuNPs) 沉积电极上的目标诱导适体位移与滚环放大 (RCA) 相结合，开发了一种简单易用的适体传感器，用于超灵敏测定活鼠伤寒沙门氏菌。目标鼠伤寒沙门氏菌与适体的异质识别和特异性结合，释放引物结合部分，导致在适体传感器表面锚定多个圆形模板。然后，开始 RCA 反应以产生具有多个串联重复序列的大量长 DNA 分子。这些 RCA 产物可以与生物素化检测探针杂交，用于适体传感器表面的酶放大电化学读数。设计的电化学适体传感器对低至 16 CFU mL-1 的鼠伤寒沙门氏菌表现出非常高的灵敏度，具有 20 至 2 × 108 CFU mL-1 的宽线性检测范围，并表现出显着的信号放大性能、可接受的重现性和低基质效应。这一提议的策略为超灵敏和方便的细菌检测提供了一个简单易行的平台，它将成为食品安全、临床诊断甚至生物威胁监测中微生物检测的有效工具。设计的电化学适体传感器对低至 16 CFU mL-1 的鼠伤寒沙门氏菌表现出非常高的灵敏度，具有 20 至 2 × 108 CFU mL-1 的宽线性检测范围，并表现出显着的信号放大性能、可接受的重现性和低基质效应。这一提议的策略为超灵敏和方便的细菌检测提供了一个简单易行的平台，它将成为食品安全、临床诊断甚至生物威胁监测中微生物检测的有效工具。设计的电化学适体传感器对低至 16 CFU mL-1 的鼠伤寒沙门氏菌表现出非常高的灵敏度，具有 20 至 2 × 108 CFU mL-1 的宽线性检测范围，并表现出显着的信号放大性能、可接受的重现性和低基质效应。这一提议的策略为超灵敏和方便的细菌检测提供了一个简单易行的平台，它将成为食品安全、临床诊断甚至生物威胁监测中微生物检测的有效工具。