Fabrication of CdSe and methylene blue multilayer film for the determination of adenine and guanine in DNA

Abstract

The fabrication of an electrode modified with cadmium selenide/methylene blue{CdSe/MB}n multilayer films is introduced via assembling layer-by-layer CdSe and methylene blue on the glassy carbon electrode surface. The multilayer films have been investigated by scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The electrode exhibited a good stability for the simultaneous determination of guanine and adenine in DNA. The experimental parameters were optimized and the limit of detection (S/N = 3) for guanine and adenine was 0.3 ng·mL−1 and 0.9 ng·mL−1, respectively, under the optimum conditions. A direct electrochemical method for simultaneous determination of guanine and adenine in DNA is presented.