Electrochemical detection of hepatitis B and papilloma virus DNAs using SWCNT array coated with gold nanoparticles

► Both random and aligned SWCNTs/Au arrays were in situ prepared on Si/SiO2 substrate. ► The array electrodes could detect lower than 1 attomole complimentary 21-base Hepatitis B DNA. ► The array electrodes could detect lower than 1 attomole complimentary 24-base papilloma DNA. ► The electrodes were capable of detecting one-base mismatched DNAs. ► The electrodes showed good stability and could be regenerated conveniently.