Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut, 71524, Egypt.
Sci Rep. 2022 Apr 28;12(1):6953. doi: 10.1038/s41598-022-10779-8.
Polyvinylpyrrolidone stabilized silver nanoparticles (PV-AgNPs) were synthesized from AgNO/trisodium citrate and with the assistance of microwave energy. The synthesized PV-AgNPs were found to own an actual peroxidase mimicking activity. This catalytic activity can oxidize the non-fluorescence reagent (o-phenylenediamine) to a high fluorescence reaction product (2,3-diaminophenazine). The reaction product exhibited a fluorescence emission at 563 nm upon the excitation at 420. Among many metals, only mercury (II) ions can inhibit the catalytic activity of PV-AgNPs nanozyme. Accordingly, the fluorescence intensity of the reaction product has been successfully quenched. This quenching effect in the fluorescence intensity was directly proportional to the concentration of mercury (II). Depending on this finding, a simple, cost-effective, and selective spectrofluorimetric approach has been designed for mercury (II) detection in water samples. The linear relationship between the inhibition in fluorescence intensity and mercury (II) concentration was found in 20-2000 nM with a detection limit of 8.9 nM.
聚维酮稳定的银纳米粒子（PV-AgNPs）是通过 AgNO3/柠檬酸钠在微波能的辅助下合成的。研究发现，合成的 PV-AgNPs 具有实际的过氧化物酶模拟活性。这种催化活性可以将非荧光试剂（邻苯二胺）氧化为高荧光反应产物（2,3-二氨基吩嗪）。在 420nm 的激发下，反应产物在 563nm 处发出荧光发射。在许多金属中，只有汞（II）离子可以抑制 PV-AgNPs 纳米酶的催化活性。因此，反应产物的荧光强度被成功猝灭。荧光强度的这种猝灭效应与汞（II）的浓度成正比。基于这一发现，设计了一种简单、经济、选择性的荧光光谱法来检测水样中的汞（II）。在 20-2000nM 范围内，荧光强度抑制与汞（II）浓度之间存在线性关系，检测限为 8.9nM。
