【摘要】 用适体(aptamer)修饰6 nm金纳米粒子制备了检测铅离子的核酸适体-金纳米粒子探针。在pH7.0的Na2HPO4-NaH2PO4缓冲溶液及NaCl介质中,该探针亦不聚集。Pb2+与探针中的aptamer可形成非常稳定的G-四分体结构,并释放出金纳米粒子。在NaCl作用下,释出的金纳米粒子聚集形成较大的金纳米粒子聚集体,导致516 nm处的吸光度降低。Pb2+浓度在0.3~10 nmol/L范围与516 nm处吸光度降低值呈线性关系,其线性回归方程为ΔA=0.0260ρ+0.01,相关系数为0.994 3,方法检出限为0.1 nmol/L Pb2+。该法用于废水样分析,结果与石墨炉原子吸收光谱法一致。更多还原

【Abstract】 The aptamer was used to modify gold nanoparticles of 6 nm to prepare the aptamer-Au probe for determination of lead.In Na2HPO4-NaH2PO4 buffer solution at pH 7.0 and in the presence of NaCl medium,the probe did not aggregate.Upon the addition of Pb2+,a stable G-quadruplex of Pb2+-aptamer would be formed to release gold nanoparticles that aggregated to form larger nanogold clusters that led to absorption at 516 nm decreased considerably.Under the chosen conditions,the decreased absorbence was linear with the Pb2+ concentration in the range of 0.3-10 nmol/L,with equation of linear regression of ΔA= 0.026 0 ρ+0.01,correlation coefficient of 0.994 3,and a detection limit of 0.1 nmol/L Pb 2+.This method was applied to the determination of Pb 2+ in wastewater sample.The results were in agreement with that of the atomic absorption spectrophotometry.更多还原