纳米金-铅过氧化物模拟酶分光光度法测定饮用水中铅离子

Determination of Pb2+ in drinking water by UV-Vis spectrophotometric based on the peroxidase activity of gold nanoparticle-lead complex

目的构建基于纳米金-铅复合物的过氧化物模拟酶活性测定饮用水中铅离子的分光光度新方法。方法在2mLEP管中依次加入65μLAuNPs,50μL一定浓度的Pb^2+溶液,pH3.3柠檬酸钠-盐酸缓冲溶液40μL,再加入55μLH2O2,30μL2,2'-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐(ABTS),加水至500μL,35℃恒温孵育80min,同时做试剂空白。用UV-2550紫外可见分光光度计进行吸收光谱扫描,以λ=417nm的吸光度进行定量。结果铅离子浓度为1.62×10^-7~1.00×10^-6mol/L(r=0.990)和1.00×10^-6~7.00×10^-6mol/L(r=0.980)时,体系的吸光度变化值与铅离子浓度呈现较好的线性关系,检出限为4.87×10^-8mol/L,加标回收率为103.30%~107.10%。结论该方法简便、快速、稳定、无需标记,检出限低于国家要求的集中式生活饮用水铅含量限值,可用于饮用水中铅离子浓度的测定。

Objective To establish a new spectrophotometric method for the determination of Pb^2+ by using the peroxidase activity of gold nanoparticle-lead complex. Methods In 2 mL EP tube,65 μL AuNPs,50 μL Pb^2+ solution,40 μL pH 3.3 sodium citrate-hydrochloric acid buffer solution,55 μL H 2 O 2 ,30 μL AuNP 2,2'-diazo-bis (3-ethyl-benzothiazolin-6-sulfonic acid) diammonium salt(ABTS) was added successively.Then water was added until 500 μL and it was incubated at 35℃ for 80min while the reagent blank was conducted.UV-2550 uv-visible spectrophotometer was used to do the absorption spectral scanning,and it was quantified by absorbance of 417nm. Results When the concentration of Pb^2+ in the range of 1.62×10^-7 ~1.00×10^-6 mol/ L(r=0.990)and 1.00×10^-6 ~7.00×10^-6 mol/L(r=0.980),its linear relationship with the absorbance change was relatively good. The detection was 4.87×10^-8 mol/L and the average recoveries was 103.30%~107.10%. Conclusion This method was simple,fast,stable and label-free.It’s detection limit is lower than the national limit of lead content in centralized drinking water,so it can be used for determination of lead ion concentration in water.