复合纳米酶传感器可视化检测水中汞离子  

Visual detection of mercury ions based on composite nano-enzyme sensor

作　　者：赵凤霞 李丹靓 陈果 邵飞 刘思汝 严杭丽 郑毅 杨胜园 梁好 ZHAO Fengxia;LI Danliang;CHEN Guo;SHAO Fei;LIU Siru;YAN Hangli;ZHENG Yi;YANG Shengyuan;LIANG Hao(Hengyang Medical School,University of South China,Hengyang 421001,China;Key Laboratory of Hengyang for Health Hazard Factors Inspection and Quarantine,Hengyang 421001,China)

机构地区：[1]南华大学衡阳医学院,衡阳421001 [2]衡阳市健康危害因子检验检疫新技术研究重点实验室,衡阳421001

出　　处：《分析试验室》2023年第10期1299-1303,共5页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金(81903369);衡阳市重点实验室项目(2018KJ110)资助。

摘　　要：基于贵金属银修饰的单壁碳纳米管(Ag-SWNTs)复合纳米酶的催化作用及L-半胱氨酸(L-Cys)和汞离子(Hg^(2+))的特异性结合作用,建立了一种快速检测Hg^(2+)的可视化比色方法。在适宜的pH条件下,当Hg^(2+)不存在时,L-Cys可抑制Ag-SWNTs酶活性,使得3,3’,5,5’-四甲基联苯胺(TMB)无法被催化氧化显色;而当Hg^(2+)存在时,Hg^(2+)可特异性结合L-Cys,Ag-SWNTs的酶活性不被抑制,TMB被催化氧化为oxTMB,溶液颜色发生由无色至蓝色的变化。在最佳实验条件下,该检测体系在最大吸收波长653 nm处的吸光度值与1.35~90.91μg/mL范围内的Hg^(2+)浓度呈良好的线性关系,回归方程为ΔA=0.0076c-0.085,相关系数是0.9930,检出限为0.44μg/mL。该方法应用于环境水中Hg^(2+)的测定,加标回收率为92.4%~99.9%。A new colorimetric method was established for the rapid visual detection of Hg^(2+) based on the catalysis of silver modified single wall carbon nanotubes(Ag-SWNTs) and the specific binding of L-Cys and mercury ions(Hg^(2+)).In the absence of Hg^(2+) at appropriate pH,L-gystein(L-Cys) can inhibit the enzymatic activity of AgSWNTs to catalyze the chromogenic reaction of 3,3′,5,5′-tetramethylbenzidine(TMB).while in the presence of Hg^(2+),Hg^(2+) can specifically bind to L-Cys to keep the enzymatic activity of Ag-SWNTs,TMB was catalyzed and oxidized to oxTMB,and the color of the solution changed from colorless to blue.Under the optimal experimental conditions,the absorbance value of the detection system at the maximum absorption wavelength of 653 nm had a good linear relationship with the concentration of Hg^(2+) in the range of 1.35-90.91 μg/mL,and the linear regression equation was ΔA=0.0076c-0.085,with the relative correlation coefficient(r) of 0.9930.The limit of detection(LOD) for Hg^(2+) was 0.44 μg/mL.This method can be applied to determine Hg^(2+) in environmental water,and the recoveries for spiking experiments were 92.4%-99.9%.

关 键 词：单壁碳纳米管 L-半胱氨酸 汞离子检测 纳米酶 催化作用 

分 类 号：R115[医药卫生—公共卫生与预防医学]