基于适配体和纳米金的石英晶体微天平传感器检测汞

A quartz crystal microbalance biosensor for detection of mercury(Ⅱ) based on aptamer and gold nanoparticles

利用石英晶体微天平(QCM)的高度灵敏性、适配体的特异性捕捉能力和纳米金的信号放大作用,构建了一种QCM生物传感器实现了对Hg^(2+)的检测。将Hg^(2+)适配体自组装于镀金的晶振片表面,作为捕获探针。将Hg^(2+)适配体修饰在纳米金表面,作为链接探针。当Hg^(2+)存在时,捕获探针与链接探针之间形成"T-Hg^(2+)-T"的三明治,使得晶振片上质量增加,从而引起其频率变化。在优化条件下,Hg^(2+)浓度在5~50 nmol/L范围内呈现出良好线性关系,检出限为2 nmol/L(n=10),pb^(2+),As^(3+)等重金属离子无明显干扰。

A quartz crystal microbalance（ QCM） biosensor was developed for the sensitive detection of mercury ions based on a short aptamer probe（ M） and gold nanoparticles（ Au-NPs）. The probe M has specific binding ability with Hg（Ⅱ）,and the Au-NPs can amplify the signal to enhance the sensitivity. The mercury-specific aptamer probes were immobilized on the surface of the gilded quartz crystal as the capture probes,and the mercury-specific aptamer probes were also linked to the Au-NPs as the linking probes. A sandwich structure of T-Hg（Ⅱ）-T would be formed by the combination of the above two components,if Hg（Ⅱ） ions existed in the detected sample. Thus the mass on the surface of the gilded quartz crystal was increased,and it resulted in an obvious change in the resonance frequency. The detection limit of this QCM biosensor was 2. 0 nmol / L（ n = 10）with a linear range of 5 ^ 50 nmol / L. pb^（2＋）,As^（3＋） and other ions had no significant interferences.