The i nteraction among Co(phen) 33+ ,6-Mercaptopurine(6-MP)and calf thymus DNA has been investigated us-ing c yclic voltammetry,differential pulse voltammetry and UV-spectra in Tris buffer solutions(pH=7.2).In the presence of6-MP,the redox peak current at0.15V for the central cobalt ion from voltammograms is significantly reduced compared with th at in the absence of6-MP and the current of a new quasi-reversible redox wave shown at-0.06V gradually increases with6-MP addition.However,when DNA is furthe r added,the peak current at0.15V is renewedly enlarged and the redox at-0.06V gr adually disappears with DNA addition.At the same time,UV-spectra of Co(phen) 33+ are regularly changed in the presence of6-MP and DNA.All results indicate t hat the obvious interaction equilibrium is proved to exist among Co(phen) 33+ ,6-MP and calf thymus DNA.
