基于金纳米粒子探针比色法检测乙基谷硫磷

Colorimetric detection of ethyazinphos-methyl based on gold nanoparticle probes

基于乙基谷硫磷在酸性条件下可以诱导金纳米粒子(AuNPs)发生聚集,建立了以AuNPs为探针、结合比色和分光光度法检测乙基谷硫磷的方法。通过改变氯金酸和还原剂柠檬酸钠的比例,制备了不同粒径的AuNPs。酸性溶液中乙基谷硫磷分子中-P=S键发生质子化,形成的-SH与Au形成S-Au键,使AuNPs发生聚集,溶液颜色由红色转变为蓝色。考察了乙酸-乙酸钠缓冲溶液的pH和浓度以及乙基谷硫磷与AuNPs的作用时间对AuNPs聚集程度的影响。在优化条件下,吸光度比值(A694 nm/A524 nm)与乙基谷硫磷浓度在0.392~0.603μmol/L范围内具有良好的线性关系,检出限为0.0782μmol/L。

Based on the aggregation of gold nanoparticles(AuNPs) induced by ethyazinphos-methyl under acidic conditions,a new method for the detection of ethyazinphos-methyl using AuNPs as a probe combined with colorimetric and Uv-visible spectrophotometry was developed.AuNPs of different sizes were prepared by varying the ratio of sodium citrate to chloroauric acid.The-P=S bond was protonated in ethyl azinphos-methyl in acidic solution,the produced-SH formed an S-Au bond with Au,causing AuNPs aggregation and the color of the solution changed from red to blue.The effects of pH and concentration of acetic acid-sodium acetate buffer solution,and the interaction time between ethyazinphos-methyl and AuNPs were investigated.There was a good linear relationship between the absorbance ratio(A694 nm/A524 nm) and the concentration of ethyl azinphos-methyl in the range of 0.392-0.603 μmol/L,and the detection limit was 0.0782 μmol/L.