Study on the interaction between bleomycin and DNA at Ni/GCE ion implantation modified electrode and its application

With a Ni/GCE ion implantation modified electrode in 0.1 mol/L HOAc - NaOAc solution ( pH 4.62), a sensitive reduction peak of bleomycin( BLM) was obtained by linear - sweep voltammetry. The peak potential is -1.16 V(vs. SCE). The peak current is proportional to the concentration of BLM. The electrochemical behavior of the system was also studied by cyclic voltammetry. The experimental results depict that the electrode process at Ni/GCE is irreversible and the reduction of BLM is accelerated obviously. Measurements of AES show that Ni is surely implanted into the surface of GCE. After adding DKA to the solution containing BLM, the peak potential is almost no change, but the peak current of BLM is decreased. The interaction between BLM and DNA at a Ni/GCE modified electrode was studied by linear sweep and cyclic voltammetry. An inactive complex of BLM with DNA was formed and resulted in a decrease of BLM concentration as well as the reduction current. The composition of the complex is estimated as BLM:DNA = 3: 1 and the combination constant is calculated as 3.16 x 10(16). Its electrochemical behavior is the same as that in the absence of DNA. The decrease in the peak current is proportional to DNA concentration and can be used to the determination of the concentration of DNA.