石墨烯修饰酶脂质体生物传感器检测重金属的研究

Detection of Heavy Metals by Graphene-modified Enzyme Liposome Biosensor

通过自组装技术将葡萄糖氧化酶脂质体与纳米石墨烯共修饰于玻碳电极表面,制备出新型葡萄糖氧化酶电化学生物传感器,并利用其构建重金属残留检测体系。结果表明,经超声处理的石墨烯片层较薄,厚度在5 nm左右;以Hg^(2+)和Cu^(2+)作为重金属模型,分别在0.15和0.20 V时出现氧化峰电流,且不同浓度下峰电流未发生偏移;Hg^(2+)在10^(-10)~10^(-5)和10^(-5)~10^(-2) mmol/L浓度范围内,工作曲线方程分别为I(%)=0.0244 lgC+0.3543和I(%)=0.1552 lgC+1.0219,决定系数R^(2)分别为0.9747和0.9937,检测限分别为10.97和3.60 ng/mL;Cu^(2+)在10^(-10)~10^(-2) mmol/L浓度范围内,工作曲线方程为I(%)=0.0406 lgC+0.8582,相关系数R^(2)为0.9885,检出限为87.70 ng/mL,说明该检测方法灵敏度高。回收率试验结果显示所建立的检测方法对检测重金属具有较高的准确度,且精密度高,具有很好的应用前景。

A novel glucose oxidase electrochemical biosensor was prepared by co-modifying glucose oxidase liposomes and nanographene on the surface of a glassy carbon electrode through self-assembly technology,and using it to construct a heavy metal residue detection system.The results showed that the ultrasonically processed graphene sheets were thinner and had a thickness of about 5 nm.Hg^(2+)and Cu^(2+)were used as models respectively.Hg^(2+)and Cu^(2+)showed oxidation peak currents at 0.15 and 0.20 V,respectively,and the peak current does not shift at different concentrations.In a certain linear range,the inhibition rate had a good linear relationship with ion concentration:Hg^(2+)was in the range of 10^(-10)~10^(-5) and 10^(-5)~10^(-2) mmol/L,the equations were I%=(0.0244 lgC+0.3543)%and I%=(0.1552 lgC+1.0219)%,the coefficient of determination R^(2) value were 0.9747 and 0.9937,and the detection limits were 10.97 ng/mL and 3.60 ng/mL,respectively;the fitting equation for Cu^(2+)at 10^(-10)~10^(-2) mmol/L was I%=(0.0406 lgC+0.8582)%,the coefficient of determination R^(2) value was 0.9885 and the detection limit was 87.70 ng/mL,which indicated that the detection method had high sensitivity.The recovery test results shows that the established detection method has high accuracy and high precision for the detection of heavy metals,and has a good application prospect.