Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, People's Republic of China.
The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, People's Republic of China.
Anal Chem. 2021 May 18;93(19):7275-7282. doi: 10.1021/acs.analchem.1c00616. Epub 2021 May 6.
Organophosphorus pesticides (OPs) can inhibit the activity of acetylcholinesterase (AChE) to induce neurological diseases. It is significant to exploit a rapid and sensitive strategy to monitor OPs. Here, a metal-organic framework (MOF) acted as a carrier to encapsulate AuNCs, which can limit the molecular motion of AuNCs, trigger the aggregation-induced emission (AIE) effect, and exhibit a strong fluorescence with a fluorescence lifetime and quantum yield of 6.83 μs and 4.63%, respectively. Then, the marriage of fluorescence and colorimetric signals was realized on the basis of the dual function of the enzymolysis product from AChE and choline oxidase (CHO) on AuNCs@ZIF-8. First, it can decompose ZIF-8 to weaken the restraint on AuNCs, and thus the fluorescence receded. Second, it can be used as a substrate for the peroxidase mimics of the released AuNCs to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) and a visible blue appeared. Thus, on the basis of the inhibition of AChE activity by OPs, a fluorescence-colorimetric dual-signal biosensor was established. In addition, colorimetric paper strips were exploited to realize a visual semiquantitative detection, and a smartphone APP was developed to make the visualization results more precise and realize real-time supervision of pesticide contamination.
有机磷农药 (OPs) 可以抑制乙酰胆碱酯酶 (AChE) 的活性，从而引发神经疾病。开发一种快速灵敏的策略来监测 OPs 具有重要意义。在这里，金属有机骨架 (MOF) 作为载体来包裹金纳米簇 (AuNCs)，可以限制 AuNCs 的分子运动，引发聚集诱导发射 (AIE) 效应，并表现出强荧光，荧光寿命和量子产率分别为 6.83 μs 和 4.63%。然后，基于 AChE 和胆碱氧化酶 (CHO) 的酶解产物对 AuNCs@ZIF-8 的双重功能，实现了荧光和比色信号的结合。首先，它可以分解 ZIF-8 以削弱对 AuNCs 的约束，从而使荧光衰退。其次，它可以作为释放的 AuNCs 的过氧化物酶模拟物的底物，氧化 3,3',5,5'-四甲基联苯胺 (TMB)，并出现可见的蓝色。因此，基于 OPs 对 AChE 活性的抑制，建立了荧光-比色双信号生物传感器。此外，还开发了比色试纸条实现了可视化半定量检测，并开发了智能手机应用程序，使可视化结果更加精确，并实现了对农药污染的实时监测。
