双酶活性金-铂双金属复合纳米酶的合成及其在有机磷农药检测中的应用

Synthesis of Au-Pt bimetallic nanozymes with dual-enzyme activity and its application in organophosphorus pesticides detection

中文关键词:  双金属复合纳米酶  比色法  乙酰胆碱酯酶  有机磷农药  智能手机可视化

英文关键词:bimetallic nanozymes  colorimetric method  acetylcholinesterase  organophosphorus pesticides  smartphone

中文摘要:

      目的 合成具有氧化酶及过氧化酶双酶活性的金-铂双金属复合纳米酶(Au-Pt bimetallic nanozymes, Au-PtNFs), 并将其应用于有机磷农药检测中。方法 采用种子介导法, 通过调整氯铂酸用量成功制备了3种Au-PtNFs, 并以3,3’,5,5’-四甲基联苯胺(3,3’5,5’-tetramethylbenzidine, TMB)为底物测定其酶活性。选择酶活性最强的一种纳米酶, 结合乙酰胆碱酯酶的催化作用, 建立有机磷农药检测方法。结果 合成的3种纳米酶均具有花状结构, 且粒径随氯铂酸用量增大而增大; 稳态动力学实验表明其均具有双酶活性且氯铂酸浓度为5 mmol/L时合成的纳米酶的酶活性最好; 以毒死蜱为目标物, 在40~90 nmol/L范围内, 620 nm处的吸光值与毒死蜱浓度对数呈良好的线性关系, 检出限为1.00 nmol/L, 同时方法具有良好的特异性和抗干扰能力, 在实际样品检测中回收率较好。利用色值分析软件实现了基于智能手机的毒死蜱检测, 线性范围为30~100 nmol/L, 检出限为1.06 nmol/L。结论 本研究成功将具有双酶活性的Au-PtNFs应用于有机磷农药检测, 为果蔬中有机磷农药可视化检测提供了一种新思路。

英文摘要:

      Objective To synthesize a Au-Pt bimetallic nanozymes (Au-PtNFs) with oxidase and peroxidase dual-enzyme activity, and apply them in detection of organophosphorus pesticide. Methods The 3 kinds of Au-PtNFs were prepared through seed-mediated method by adjusting the amount of chloroplatinic acid, and their enzyme activities were determined using 3,3’,5,5’-tetramethylbenzidine (TMB) as the substrate. The nanozyme exhibiting the highest enzyme activity was selected and combined with the catalytic effect of acetylcholinesterase to establish a detection method for organophosphorus pesticide. Results The 3 kinds of prepared nanozymes all had flower-like structures, and the particle size enhanced with the increasement of chloroplatinic acid concentration. Steady-state dynamic experiments showed that all bimetallic nanozymes had dual-enzyme activity, and the best enzyme activity was obtained when the concentration of chloroplatinic acid was 5 mmol/L. Absorption at 620 nm exhibited a good linear correlation with the logarithm of chlorpyrifos concentration in the range of 40–90 nmol/L, and the limit of detection was 1.00 nmol/L. The method demonstrated excellent specificity and anti-interference ability, and achieved great recovery rate in real samples. Color value analysis software was used for the detection of chlorpyrifos based on smartphone. The linear range was 30–100 nmol/L and the limit of detection was 1.06 nmol/L. Conclusion The prepared Au-PtNFs exhibiting dual-enzyme activity are effectively utilized for detection of organophosphorus pesticides, which offers a novel perspective for visual detection of organophosphorus pesticides in fruits and vegetables.