Voltammetric studies on the recognition of a copper complex to single- and double-stranded DNA and its application in gene biosensor

Abstract

A mixed-ligands copper complex [Cu(phendione)(DAP)]SO4 (phendione = 1,10-phenanthroline-5,6-dione, DAP = 2,3-diaminophenazine) was synthesized. Cyclic voltammetry showed that the complex underwent an obvious decrease of redox peak currents and positive shift of formal potential after interaction with double-stranded DNA (dsDNA), suggesting that the copper complex behaved as a typical metallointercalator for dsDNA, The recognition properties of the copper complex to single-stranded DNA (ssDNA) and dsDNA were assessed using surface-based electrochemical methods and the results suggested that the complex had obviously different redox signals at ssDNA and dsDNA modified electrodes. The copper complex was further used as an electroactive indicator for the detection of cauliflower mosaic virus (CaMV) 35S promoter gene. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.