Electrochemical behaviors and simultaneous determination of guanine and adenine based on highly ordered Pd-nanowire arrays-modified glassy carbon electrode

摘要

A novel electrochemical sensor for the simultaneous detection of guanine (G) and adenine (A) was developed on a Pd nanowire arrays-modified carbon glassy electrode (Pd NWAs). The Pd NWAs were obtained via the direct electrode position of Pd on a glassy carbon electrode within the pores of an anodized aluminum oxide membrane. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDS) techniques were used to examine the Pd NWAs structures. The Pd nanowire arrays have high electrochemically active surfaces, and this modified electrode exhibits excellent and persistent electro-oxidation behavior toward G and A. The Pd NWAs modified electrodes significantly increases oxidation peak currents but reduces the peaks potential of G and A. For the Pd NWAs-modified electrode, the peak potentials of G and A are negatively shifted to 0.69 and 0.97 V, respectively. Differential pulse voltammetry (DPV) was proposed for the simultaneous determination of G and A. Under the selected conditions, the oxidation peak currents were proportional to guanine and adenine, ranging from 2 ??M to 200 ??M and 4 ??M to 200 ??M with detection limits at 0.7 ??M and 1 ??M, respectively. Simultaneously, the proposed method was successfully applied for the determination of guanine and adenine in denatured DNA samples with satisfactory results.