基于共面薄膜金电极的三磷酸腺苷适体传感器

摘要

Thin-film gold electrodes were fabricated based on MEMS technology. Adenosine triphosphate with mercapto-group was immobilized on a surface of gold electrode via self-assembly. An aptamer-based amperometric biosensor was constructed to measure the concentration of the ATP that using aptamer as the recognition element based on coplanar thin-film gold electrode. Adenosine triphosphate was detected by the characteristic impedance changes based on phosphate backbone of nucleic with negatively charge that electrostatic reject [ Fe( CN) 6 ] 3-/4-. Firstly, under the conditions of bare gold electrode and before and after ATP was added and whether 6-mercapto-1-hexanol was closed on electrode and the different self-assembly time (3, 8, 15, 24 and 30 h),the electrode of impedance changes in electrochemical impedance solution was researched with electrochemical Impedance Spectroscopy. The experiments show that the measurable linearity range of adenosine triphosphate is 1-500 nmol/L, the detection limit is 1 nmol/L and the correlation coefficient was 0 . 9842 when the time of the self-assembly was 24 h and closed gold electrode with 6-mercapto-hexanol. This electrochemical aptasensor was simplicity and has low detection limit and good repeatability.%为了检测三磷酸腺苷( ATP)的浓度,利用微系统( MEMS)技术小批量加工薄膜金电极,采用自组装法将巯基修饰的三磷酸腺苷适体固定到金电极表面,以三磷酸腺苷适体作为识别元件,构建了一种基于共面薄膜金电极的三磷酸腺苷适体传感器。依据核酸磷酸骨架荷负电特性静电排斥[Fe(CN)6]3-/4-所引起的阻抗变化实现对ATP浓度的检测。首先采用电化学阻抗谱法研究了裸金电极及ATP加入前后、6-巯基己醇封闭电极前后以及不同自组装时间(3,8,15,24和30 h)条件下,电极在电化学阻抗溶液中阻抗值变化。然后研究了不同浓度ATP适体传感器的电化学阻抗谱以及适体传感器的线性度和重复性。结果表明,在自组装时间为24 h,使用6-巯基己醇封闭金电极的条件下,此传感器线性测量范围可达到1~500 nmol/L,检出限为1 nmol/L,线性相关系数为0.9842。此传感器制作简单,检出限低且重复性好。