Carbon-nanotube-modified glassy carbon electrodes for amplified label-free electrochemical detection of DNA hybridization

摘要

The preparation and attractive performance of carbon-nanotube modified glassy-carbon(CNT/GC)electrodes for improved detection of purines,nucleic acids,and DNA hybridization are described.The surface-confined multiwall carbon-nanotube(MWCNT)facilitates the adsorptive accumulation of the guanine nucleobase and greatly enhances its oxidation signal.The advantages of CNT/GC electrodes are illustrated from comparison to the common unmodified glassy carbon,carbon paste and graphite pencil electrodes.The dramatic amplification of the guanine signal has been combined with a label-free electrical detection of DNA hybridization.Factors influencing the enhancement of the guanine signal are assessed and optimized.The performance characteristics of the amplified label-free electrochemical detection of DNA hybridization are reported in connection to measurements of nucleic-acid segments related to the breast-cancer BRCA1 gene.