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利用Hg2+的核酸适体修饰纳米金形成探针建立了一种定量检测Hg2+离子的方法.Hg2+适体吸附在纳米金表面,使纳米金的稳定性增强,抑制氯化钠对纳米金的团聚作用.溶液中有Hg2+离子存在时,由于适体与纳米金的吸附作用小于适体与Hg2+离子的亲和作用,纳米金失去适体保护在氯化钠作用下发生团聚.溶液颜色由红变蓝,紫外-可见光谱最大吸收峰由520 nm红移至620 nm.在优化条件下,吸光度的比值(A620/A520)与Hg2+离子浓度在5.0×10-9～7.2×10-7mol·L-1范围内呈线性关系,检测限可达3.3×10-10mol·L-1.研究了K+,Ca2+等常见离子的干扰,结果表明该方法具有良好的选择性.
A method for quantitative determination of Hg2 + ions was established by using Hg2 + aptamer modified gold nanoparticle formation probe. Hg2 + aptamer adsorbed on the surface of gold nanoparticles enhanced the stability of gold nanoparticles and inhibited the agglomeration of gold nanoparticles by sodium chloride In the presence of Hg2 + ions in the solution, the aptamer and nanogold adsorption is less than the affinity of the aptamer and Hg2 + ions, the aptamer gold nanoparticles lose the aptamer protection and agglomeration occurs under the action of sodium chloride.The color of the solution changes from reddish to blue , The maximum absorption peak of UV-visible spectrum was red-shifted from 520 nm to 620 nm. Under optimal conditions, the absorbance ratio (A620 / A520) and Hg2 + ion concentration were 5.0 × 10-9 ~ 7.2 × 10-7 mol·L-1 The detection limit was up to 3.3 × 10-10 mol·L-1. The interferences of common ions such as K + and Ca2 + were studied. The results showed that this method has good selectivity.