Carbon Nanotubes Modified Electrodes Preparation Of Dna Biosensor Research

The DNA biosensor based on single-walled carbon nanotubes（SWNTs） has notonly good electricity of carbon nanotubes but also the self-identification of DNA, andthere are high efficiency in the fields of biological detecting, electrochemical etc. In thispaper SWNTs/DNA sensor was fabricate through single-walled carbon nanotubesdecorated by DNA. The electrschemical performance testing of SWNTs/DNA sensorwas detected and the detection to Pb2+was discussed primarily by met-SWNTs/DNAsensor.In this paper, SWNTs was prepaerd by arc discharge and purified though nitricacid reflux. It is found that the higher pure SWNTs is obtained by that method aftercharacterized. And we also attempted to study the influence on the diameter distributionof SWNTs tuned by secondary arc discharge. It is shown that SWNTs have narrowerdiameter distribution and a little bit smaller mean diameter, nearly1.36nm.Met-SWNTs/DNA sensor was fabicated, its electrschemical performance testingwas reaserched by cyclic voltammetry and elecctrochemical impedance spectroscopyand then we could know that this sensor had a little smaller impedance. The Pb2+concentration was detected by this sensor via differential pulse voltammetry (DPV), andthe detection limit is4.1×10-10mol L1. The fabricated sensor has many advantages overother procedures for Pb2+detection, such as high sensitivity, good selectivity, lowdetection limits, simplicity, rapidness and low cost.