纳米TiO2管电化学生物传感器用于测定水体中微囊藻毒素

制作了辣根过氧化物酶和溶胶-凝胶结合Nafion-TiO2修饰石墨电化学传感器,用示差脉冲伏安法研究了该修饰电极的电化学性质,并优化了微囊藻毒素-LR(MC-LR)的测定条件.结果表明,在pH=6.5柠檬酸-NaOH-HCl缓冲溶液中,采用该修饰电极示差脉冲伏安法测定MC-LR,质量浓度在10-5～1μg/L范围内呈良好的线性关系,脉冲伏安法测定微囊藻毒素线性方程为100Δi=0.142 2logC+0.799 7,相关系数为0.995 0,最低检测限达10-6μg/L.电极的重现性及稳定性较好,连续测定10次,相对标准偏差为2.5%;4℃下储存28d后示差脉冲信号无明显变化;应用于饮用水中MC-LR的测定,样品的回收率为99.3%～102.9%.该传感器灵敏度高、稳定性好.

Nano-TiO2 tubes electrochemical biosensor for the determination of microcystins in water

Microcystin-LR pollution is one of the biggest problems,and received wide attention.A competitive binding TiO2 which modifies graphite electrode with a sandwich film(antibody,antigen and enzyme-labeled antibody) immunoassay was set for the determination of Microcystin-LR(MC-LR).A classical three-electrode system was adopted.Antibody,antigen and enzyme-labeled antibody(fixed in TiO2) which modified graphite electrode acted as the work electrode,a platinum electrode as the counter electrode and Ag/AgCl as the reference electrode.The characteristics of modified electrode were investigated by Differential pulse voltammetry(DPV) methods.Under optimal conditions,linear relationship between Δi and concentration of MC-LR was obtained in the range of 10-5～1 μg/L,with relative coefficients of 0.995 0.The detection limit of the biosensor for MC-LR was down to 10-6 μg/L.The biosensor exhibited good reproducibility for the signal with RSD(n=10) of 2.5% and good stability in 28 days.The average recoveries were in the range of 99.3%~102.9%.The method was sensitive,rapid and reproducible,and was suitable for the determination of MC-LR in the field of environmental monitoring.