适配子纳米生物传感器在青霉素检测中的应用

Application of aptamer nano-biosensor in penicillin detection

通过脉冲腐蚀法对硅片进行多孔硅的制备，利用玻片通过对共价法、离子吸附法和APTES修饰的戊二醛交联法3种固定适配子方法的对比，以确定较好的固定青霉素适配子的方法。将适配子固定在多孔硅上后，利用交流阻抗法对加入青霉素前后传感器阻抗值进行测定、对比，构建等效电路并进行阻抗拟合。对多孔硅传感器的Nyquist谱图进行分析以确定多孔硅表面成功固定了青霉素适配子，从而证明构建纳米生物传感器成功。传感器的线性检测范围为0．05～0．2mg/L，检测限为0．05mg／L。

Porous silicon （PS） was made from silicons by a pulsed current etching method. Three methods were tested to choose the best way of immobilizing penicillin aptamer on glass sheet, called the covalent bonding method, ion-absorbing method, and APTES-modified glutaraldehyde cross-linking method. After penicillin aptamer was immobilized on the modified PS, the impedances were determined and compared by AC impedence method under conditions of adding and without adding penicillin. Then, an equivalent circuit was established for impedance fitting. The Nyquist plots of PS sensor could prove that the aptamer was immobilized and 0.05 -0.20 mg/L. The sensitivity the nano-biosensor established. The linear range of the sensor was limit was 0.05 mg/L