A highly sensitive and selective method was developed for both UV–vis spectrophotometric and fluorimetric determination of organophosphorus pesticides (OPs). This method used silver nanoparticles (AgNPs) modified with graphitic carbon nitride (g-C₃N₄). The AgNPs reduced the fluorescence intensity of g-C₃N₄. Acetylthiocholine (ATCh) could be catalytically hydrolyzed by acetylcholinesterase (AChE) to form thiocholine, which induces aggregation of the AgNPs. This aggregation led to the recovery of the blue fluorescence of g-C₃N₄, with excitation/emission peaks at 310/460 nm. This fluorescence intensity could be reduced again in the presence of OPs because of the inhibitory effect of OPs on the activity of AChE. The degree of reduction was found to be proportional to the concentration of OPs, and the limit of fluorometric detection was 0.0324 μg/L (S/N = 3). In addition, the absorption of the g-C₃N₄/AgNPs at 390 nm decreased because of the aggregation of the AgNPs, but was recovered in presence of OPs because of the inhibition of enzyme activity by OPs. This method was successfully applied to the analysis of parathion-methyl in real samples.

开发了一种高灵敏度和选择性的方法，用于有机磷农药 (OP) 的紫外-可见分光光度法和荧光测定。该方法使用用石墨氮化碳（gC ₃ N ₄ ）改性的银纳米颗粒（AgNP）。 AgNPs降低了gC ₃ N ₄的荧光强度。乙酰硫胆碱（ATCh）可以被乙酰胆碱酯酶（AChE）催化水解形成硫胆碱，从而诱导AgNPs聚集。这种聚集导致 gC ₃ N ₄的蓝色荧光恢复，激发/发射峰位于 310/460 nm。由于OPs对AChE活性的抑制作用，当OPs存在时，该荧光强度会再次降低。发现还原程度与OPs浓度成正比，荧光检测限为0.0324 μg/L（S/N = 3）。另外，gC ₃ N ₄ /AgNPs在390nm处的吸收由于AgNPs的聚集而降低，但由于OPs对酶活性的抑制而在OPs存在下恢复。该方法成功应用于实际样品中甲基对硫磷的分析。