School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 266 Xincun Xilu, Zibo, 255049, China.
Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, No. 266 Xincun Xilu, Zibo, 255049, China.
Anal Bioanal Chem. 2023 Sep;415(23):5833-5844. doi: 10.1007/s00216-023-04864-8. Epub 2023 Jul 21.
A highly selective and sensitive "on-off-on" electrochemiluminescence (ECL) aptasensor based on a self-enhanced luminophore was developed for the detection of ochratoxin A (OTA). Specifically, polyethyleneimine functionalized multi-walled carbon nanotubes decorated with gold nanoparticles (AuNPs-PEI-MWCNTs) were used as the electrode matrix to accelerate electron transfer and provide a favorable microenvironment for self-enhanced luminophore loading and ECL signal enhancement. In addition, black phosphorus quantum dots (BPQDs) were used as co-reactants of the ECL reagent tris (2,2'-bipyridyl) ruthenium(II) (Ru(bpy)) in ECL experiments, and the reaction mechanism was investigated. The self-enhanced luminophore Ru@SiO-BPQDs was obtained by encapsulating Ru(bpy) in silica (SiO) nanoparticles and then combining it with BPQDs through electrostatic interaction. In conventional ECL systems, the emitter and its co-reactants reacted via the inter-nanoparticle pathway, leading to long distance electron transfer. However, the electron transfer distance in the self-enhanced luminophore was significantly shortened due to the intra-nanoparticle electron transfer pathway because BPQDs and oxidized Ru(bpy) were bound within one nanoparticle, thereby improving ECL efficiency to achieve the first "switch-on" state. Then, the luminophore was quenched using ferrocenes (Fc) modified on an aptamer to achieve the "switch-off" state. Finally, OTA was specifically identified by the adapter, causing Fc to be released from the sensor interface, restoring the ECL intensity to achieve the second "switch-on" state. Under optimal conditions, the aptasensor exhibited good sensitivity, stability, and reproducibility, with a linear detection range from 0.1 to 320 ng/mL and a detection limit of 0.03 ng/mL. The novel ECL aptasensor provided a common analytical tool for the detection of mycotoxins and other small molecules.
基于自增强发光体的高选择性和高灵敏度的“开-关-开”电化学发光（ECL）适体传感器被开发用于检测赭曲霉毒素 A（OTA）。具体来说，使用聚乙烯亚胺功能化的多壁碳纳米管修饰金纳米粒子（AuNPs-PEI-MWCNTs）作为电极基质，以加速电子转移并为自增强发光体负载和 ECL 信号增强提供有利的微环境。此外，在 ECL 实验中，将黑磷量子点（BPQDs）用作 ECL 试剂三（2,2'-联吡啶）钌（II）（Ru（bpy））的共反应物，并研究了反应机制。自增强发光体 Ru@SiO-BPQDs 通过将 Ru（bpy）封装在二氧化硅（SiO）纳米粒子中，然后通过静电相互作用与 BPQDs 结合而获得。在传统的 ECL 系统中，发射器及其共反应物通过纳米颗粒间途径反应，导致长距离电子转移。然而，由于自增强发光体中的电子转移距离显著缩短，因为 BPQDs 和氧化的 Ru（bpy）结合在一个纳米粒子内，从而提高了 ECL 效率，实现了第一个“开启”状态。然后，使用修饰在适配体上的二茂铁（Fc）使发光体猝灭，以实现“关闭”状态。最后，适配体特异性识别 OTA，导致 Fc 从传感器界面释放，恢复 ECL 强度，实现第二个“开启”状态。在最佳条件下，适体传感器表现出良好的灵敏度、稳定性和重现性，线性检测范围为 0.1 至 320 ng/mL，检测限为 0.03 ng/mL。新型 ECL 适体传感器为检测真菌毒素和其他小分子提供了一种通用的分析工具。
