Fabrication of nanometer electrochemical interface and the voltammetric behaviour of deoxyribonucleic acid bases

A novel single wall nanotube (SWNT) compound poly (acridine orange) modified electrode (SWNTs/POAOE) was prepared at glassy carbon electrode (GCE), which combined the electrocatalytical capability of nanomaterials with the molecular recognition ability of polymer film, and it could be used for simultaneous determination of bases in deoxyribonucleic acid (DNA). The SWNTs/POAOE showed excellent electrocatalytic activity toward electro-oxidation of adenine (ADE), guanine (GUA), cytosine (CYT) and thymine (THY). The oxidation peaks of purines and pyrimidines could be entirely separated at a same SWNTs/POAOE, two well-defined oxidation peaks were observed at about 0.7 V for GUA and 1.0 V for ADE in pH 7.0 Bristton-Robinson (B.R.) buffer. The detection limits were 1.8 x 10(-9) mol/L for ADE, and 9.0 x 10(-10) mol/L for GUA. The pyrimidine bases did not interfere with the determination of ADE and GUA. This electrode presented here could be used for the simultaneous determination of ADE and GUA in DNA.