Studies on the Interaction Mechanism of 1,10-Phenanthroline Cobalt(II) Complex with DNA and Preparation of Electrochemical DNA Biosensor

Fluorescence spectroscopy and ultraviolet (UV) spectroscopy techniques coupled with cyclic voltammetry (CV) were used to study the interaction between salmon sperm DNA and 1,10-Phenanthroline cobalt(II) complex, [Co(phen)(2)(Cl)(H(2)O)]Cl·H(2)O, where phen = 1,10-phenanthroline. The interaction between [Co(phen)(2)(Cl)(H(2)O)](+) and double-strand DNA (dsDNA) was identified to be intercalative mode. An electrochemical DNA biosensor was developed by covalent immobilization of probe single-strand DNA (ssDNA) related to human immunodeficiency virus (HIV) on the activated glassy carbon electrode (GCE). With [Co(phen)(2)(Cl)(H(2)O)](+) being the novel electrochemical hybridization indicator, the selectivity of ssDNA-modified electrode was investigated and selective detection of complementary ssDNA was achieved using differential pulse voltammetry (DPV).