A photoelectrochemical (PEC) aptasensing platform is devised for sensitive detection of an organophosphorus pesticide based on dissolution of core-shell MnO2 nanoflower@CdS (MnO2 NF@CdS) by thiocholine (TCh). TCH is produced from the butyrylcholinesterase-acetylthiocholine system, accompanied by target-triggered rolling circle amplification (RCA). The core-shell MnO2 NF@CdS with excellent PEC performance was synthesized and employed as a photo-sensing platform. The target was detected on a functionalized magnetic probe with the corresponding aptamer. Upon malathion introduction, the aptamer was detached from the magnetic beads, while capture DNA (cDNA, with primer fragment) remained on the beads. The primer fragment in cDNA can trigger the RCA reaction to form a long single-stranded DNA (ssDNA). Furthermore, a large number of butyrylcholinesterase (BChE) were assembled on the long ssDNA strands through the hybridization with the S2-Au-BChE probe. Thereafter, TCh generated from hydrolysis of ATCh by BChE can reduce MnO2 NF (core) to Mn2+ and release the CdS nanoparticles (shell) from the platform electrode, significantly enhancing the PEC signal. Under optimal conditions, the proposed aptasensor exhibited high sensitivity for malathion with a low detection limit of 0.68 pg mL−1. Meanwhile, it also presents outstanding specificity, reproducibility, and stability. Importantly, the sensing platform provides a new concept for detection of pesticide. Graphical abstract Herein, this work devised a photoelectrochemical (PEC) aptasensing platform for sensitive detection of organophosphorus pesticide based on dissolution of core-shell MnO2 nanoflower@CdS (MnO2 NF@CdS) by the as-produced thiocholine (TCh) from the butyrylcholinesterase-acetylthiocholine system, accompanying with the target-triggered rolling circle amplification (RCA). Herein, this work devised a photoelectrochemical (PEC) aptasensing platform for sensitive detection of organophosphorus pesticide based on dissolution of core-shell MnO2 nanoflower@CdS (MnO2 NF@CdS) by the as-produced thiocholine (TCh) from the butyrylcholinesterase-acetylthiocholine system, accompanying with the target-triggered rolling circle amplification (RCA).

中文翻译：

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基于丁酰胆碱酯酶介导核壳MnO2纳米花@CdS溶解的滚环放大促进磁控光电化学有机磷农药生物传感器

基于硫代胆碱 (TCh) 对核壳型 MnO2 纳米花@CdS (MnO2 NF@CdS) 的溶解，设计了一种光电化学 (PEC) 适配传感平台，用于灵敏检测有机磷农药。TCH 由丁酰胆碱酯酶-乙酰硫代胆碱系统产生，伴随着目标触发的滚环扩增 (RCA)。合成了具有优异 PEC 性能的核壳型 MnO2 NF@CdS，并将其用作光敏平台。在具有相应适体的功能化磁性探针上检测到目标。引入马拉硫磷后，适体与磁珠分离，而捕获 DNA（cDNA，带有引物片段）保留在磁珠上。cDNA 中的引物片段可以触发 RCA 反应，形成长单链 DNA（ssDNA）。此外，通过与 S2-Au-BChE 探针杂交，大量丁酰胆碱酯酶 (BChE) 组装在长 ssDNA 链上。此后，由 BChE 水解 ATCh 产生的 TCh 可以将 MnO2 NF（核心）还原为 Mn2+ 并从平台电极释放 CdS 纳米颗粒（壳），显着增强 PEC 信号。在最佳条件下，所提出的适体传感器对马拉硫磷表现出高灵敏度，检测限低至 0.68 pg mL-1。同时，它还具有突出的特异性、重现性和稳定性。重要的是，传感平台为农药检测提供了一个新概念。图形摘要在此，这项工作设计了一种光电化学 (PEC) 适配传感平台，基于丁酰胆碱酯酶 - 乙酰硫代胆碱系统中产生的硫代胆碱 (TCh) 溶解核壳型 MnO2 纳米花@CdS (MnO2 NF@CdS)，用于灵敏检测有机磷农药。与目标触发的滚环扩增（RCA）。在此，本工作设计了一种光电化学 (PEC) 适配传感平台，基于丁酰胆碱酯酶-乙酰硫代胆碱系统中生成的硫代胆碱 (TCh) 溶解核壳型 MnO2 纳米花@CdS (MnO2 NF@CdS) 来灵敏检测有机磷农药，伴随着目标触发的滚环扩增（RCA）。伴随着目标触发的滚环扩增（RCA）。在此，本工作设计了一种光电化学 (PEC) 适配传感平台，基于丁酰胆碱酯酶-乙酰硫代胆碱系统中产生的硫代胆碱 (TCh) 溶解核壳型 MnO2 纳米花@CdS (MnO2 NF@CdS) 来灵敏检测有机磷农药，伴随着目标触发的滚环扩增（RCA）。伴随着目标触发的滚环扩增（RCA）。在此，本工作设计了一种光电化学 (PEC) 适配传感平台，基于丁酰胆碱酯酶-乙酰硫代胆碱系统中产生的硫代胆碱 (TCh) 溶解核壳型 MnO2 纳米花@CdS (MnO2 NF@CdS) 来灵敏检测有机磷农药，伴随着目标触发的滚环扩增（RCA）。