Selective enhanced electrochemical response of DNA bases on carbon nanotube-gold nanocomposites modified gold electrode

In this study, multi-walled carbon nanotube-gold (MWCNT-Au) nanocomposites have been synthesized by using one-step method, where gold nanoparticles were deposited on the sidewall of multiwalled carbon nanotubes directly and orderly. By combination of these MWCNT-Au nanocomposites with electrochemical biosensing, our study indicates that the modification of gold electrode with these nanocomposites could remarkably enhance the electrochemical response of DNA bases and extends the application of relevant electrodes. It is noted that the selective enhancement effect of DNA bases was related to the special interaction of different bases with the nanointerface and the large effective surface area of this modified electrode. Especially, the pyrimidine bases' signal has been enhanced for several times at the MWCNT-Au nanocomposites modified electrodes than that of the carbon nanotube modified electrodes, suggesting that the MWCNT-Au nanocomposite modified gold electrodes could selectively and sensitively recognize the pyrimidine from other bases in DNA related determinations. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim