Immobilization and electro-oxidation of calf thymus deoxyribonucleic acid at alkylamine modified carbon nanotube electrode and its interaction with promethazine hydrochloride

Immobilization and electro-oxidation of calf thymus double-stranded deoxyribonucleic acid (dsDNA) were investigated at carbon nanotube (CNT) electrode modified with ethylene diamine. Well-defined oxidation peak and large peak current of dsDNA oxidation have been observed even at very low dsDNA concentration (40 ng mL−1). Interaction between promethazine hydrochloride and immobilized dsDNA was also investigated. The intercalative binding of promethazine hydrochloride with dsDNA results in an increase of electrochemical impedance and a decrease of dsDNA oxidation peak current. The possibility using functional CNT electrode immobilized dsDNA to sense promethazine hydrochloride was also explored.