Electrochemical Study on the Interaction Between Dopamine and Deoxyribonucleic Acid Using a Glassy Carbon Electrode Modified With Silver-Doped Poly Cysteine Membrane

摘要

The interaction of dopamine (DA) with herring sperm deoxyribonucleic acid (ds-DNA) has beenstudied by cyclic voltammetry (CV) at a glassy carbon electrode (GCE) modified with silver-dopedpoly cysteine membrane (Ag NPs/Pcys/GCE). The modified electrode exhibited excellent catalyticproperties for the redox reaction of DA in 0.1 mol/L phosphate buffered saline (PBS) of pH 7.0. Asadded DNA into the DA solution, the oxidation peak current of DA decreases as well as the peakpotential shifts negatively and no new peaks appear. Based on the electrochemical results, someelectrochemical parameters, such as the electron transfer coefficient (), the standard rate constant ofthe electrode reaction (Ks) were calculated in the absence and presence of DNA. The binding ratio (m)and the apparent binding constant () were also calculated. The observed negative shift in peakpotential of DA in the presence of DNA indicated that DA reacted with DNA via an electrostaticbinding mode. Furthermore, the hyperchromic effect of DA in ultraviolet visible spectroscopy (UV- Vis) after it interacted with DNA confirmed above conclusions obtained from electrochemical method.