基于镉特异性功能化核酸适配体测定痕量镉的共振光散射新方法

摘要

镉特异性功能化核酸适配体(FACd)在无镉体系中能阻碍金纳米(GNPs)与罗丹明6G(Rh6G)聚集,体系共振光散射强度较低.当体系中存在镉离子时,FACd与之特异性结合,从RNA位点处断裂产生适配体片段(FAF), FAF与GNPs和Rh6G形成GNPs-FAF-Rh6G聚合物,共振光散射强度大幅增加,共振光散射强度值(IRLS)与镉的浓度(cCd2+)在0.28~11.2 ng/mL范围内呈现良好线性关系,检出限为0.04 ng/mL,相对标准偏差≤5%,加标回收率为96.4% ~101.4%.%Cadmium specific functional aptamer(FACd) can hinder gold nanoparticles and Rhodamine 6G from gathering in a system without cadmium,keep system's resonant light scattering at a low level.When cadmium exist in system,it can specific binding with FACdand activating enzyme activity of FACd,FACd break from the RNA site,fragments(FAF) form large size Rh6G-FAF-GNPs polymer with Rh6G and GNPs,resulting a greatly increase of system's resonant light scattering.RLS has a good linear relationship with cadmium ion concentration in range of 0.28~11.2 ng/mL,limit of detection is 0.04 ng/mL,relative standard deviation is less than 5%,adding standard recovery is 96.4% ~101.4%.