多壁碳纳米管-Nafion/纳米金构建阻抗传感器研究

摘要

A novel electrochemical impedance sensor for determination of human telomere DNA is developed on basis of MWNT-Nafion/gold nanoparticles( GNPs)modified electrode. The bare Au electrode is first coated with MWNT Nafion films by dropping,and then GNPs are electro chemical deposited onto surface of MWNT-Nafion modified Au ( MWNTs-Nafion/GNPs/Au ) electrode. Then DNA is fabricated by using GNPs as carrier to immobilize human telomere DNA. Under the optimized experimental conditions,the sensor is used in detection of human telomere DNA,the result shows that the target human telomere DNA concentration is in the range of 1. 0 × 10 -13~5. 0 ×10 -11 mol/L which has good linear relationship with a detection limit of 2. 5 ×10-14 mol/L(S/N=3). Selectivity of detection is obviously improved using MWNT as substrate deposited GNPs modified electrode.%利用多壁碳纳米管（ MWNT）—Nafion和纳米金（ GNPs）修饰金电极构建了一种简单、灵敏检测人端粒DNA的电化学阻抗传感器。首先将Nafion分散的MWNT滴涂于Au电极表面，再利用电化学沉积法将GNPs沉积到MWNT—Nafion修饰Au电极表面，以GNPs为载体固定人端粒探针DNA制备DNA传感器。在最优实验条件下，将传感器用于人端粒DNA的检测中，结果表明：目标人端粒DNA的线性范围为1.0×10－13～5.0×10－11mol/L，检出限（S/N＝3）为2.5×10－14mol/L。采用MWNT为基底沉积GNPs修饰电极检测的灵敏度显著提高。