A novel electrochemical sensor based on Cu@Ni/MWCNTs nanocomposite for simultaneous determination of guanine and adenine

A novel electrochemical sensing platform based on combination of multi-walled carbon nanotubes and copper nickel hybrid nanoparticles (Cu@Ni/MWCNTs) was developed for simultaneous detection of guanine (G) and adenine (A). The Ni/MWCNTs and Cu@Ni/MWCNTs nanocomposites were characterized by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical behaviors of G and A on the modified electrode were explored by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in phosphate buffer with pH 3.0. Under the optimal conditions, electrical signals were linear over the concentration ranges from 5.0 to 180 mu M and 8.0 to 150 mu M for simultaneous determination G and A with the detection limit as low as 0.35 mu M and 0.56 mu M (S/N = 3), respectively. Furthermore, linear concentration ranges in individual determination are 1.0-180 mu M and 2.0-150 mu M with detection limits of 0.17 mu M and 0.33 mu M (S/N = 3) for G and A, respectively. The sensor was successfully used to quantify G and A in real samples. The Cu@ Ni/MWCNTs composite presented here can serve as a promising candidate for developing electrochemical sensor devices and plays an important role in widespread fields.