基于点击化学和非巯基DNA修饰纳米金的维生素C检测

Detection of vitamin C based on click chemistry using nonthiolated DNA modified gold nanoparticles

目的建立一种基于点击化学和非巯基DNA修饰的叠氮纳米金的可视化维生素C(vitaminC,VC)检测方法。方法用一端有多个腺嘌呤核苷酸的非巯基DNA修饰纳米金,再与一端有叠氮基的互补链杂交,形成表面暴露出叠氮基团的叠氮纳米金。在VC的存在下,将Cu^(2+)还原成Cu^(+),催化叠氮纳米金与三炔丙基胺发生点击化学反应,使叠氮纳米金聚集,引起光谱和颜色的变化。通过光谱和颜色的变化进行VC检测。结果在pH为7、Cu^(2+)浓度为100μmol/L、三炔丙基胺浓度为3μmol/L和反应时间12 min的最优条件下,用分光光度计检测VC的检出限为0.042mg/L,目视的检出限为0.05mg/L。该方法成功用于饮料中VC的测定,呈现了良好的回收率,从而验证了该方法的可靠性和可行性。结论这项研究提供了一种简便、超灵敏的VC检测方法,可用于VC的微量可视化检测。

Objective To establish a visualization vitamin C(VC)detection method based on click chemistry using nonthiolated DNA modified azide gold nanoparticles.Methods By modifying gold nanoparticles with DNA containing PloyA at one end and hybridizing with complementary chains containing azide groups at the other end,a gold nanoparticles with azide groups was formed.Cu^(+)would cataly a click chemical reaction between the azide gold nanoparticles and the tripropargylamine,which reduced from Cu^(2+)in the presence of VC,that causing aggregation of the azide gold nanoparticles,accompanying the spectra variation and color change.Through the spectra variation and color change,a VC detection method was constructed.Results Under the optimized condition of pH 7,Cu^(2+)concentration 100μmol/L,tripropargylamine concentration 3μmol/L and reaction time 12 min,the limit of detection of VC was 0.042 mg/L and 0.05 mg/L using photometer and visual colorimetry separately.The method had been successfully applied to the determination of VC in beverages,showed a good recovery rate,thus verifying the reliability and feasibility of the method.Conclusion This study provides a simple and ultra-sensitive method for VC detection,which can be used for micro-visual detection of VC.