Novel strategy of electrochemical analysis of DNA bases with enhanced performance based on copper-nickel nanosphere decorated N,B-doped reduced graphene oxide

Design of suitable nanocomposites with tailored structures was significant in the fabrication of effective and reliable electrochemical sensors. Herein, the copper-nickel@nitrogen, boron-doped reduced graphene oxide (Cu-Ni@N,B-rGO) was successfully synthesized, which exhibited superior electrocatalytic performance towards guanine (G) and adenine (A) oxidation. The Cu-Ni NPs were sequentially decorated on N,B-rGO substrate via an environmentally friendly reduction strategy, which utilized glucose as reducer and stabilizing agent. The nanocomposites with large specific surface area, remarkable conductivity and high catalytic activity showed prominent synergistic effect owning to the uniform dispersion of Cu-Ni NPs on the surface of N,B-rGO. When applied to analysis of G and A using DPV, the wide linear ranges of 1.0-160.0 mu M and 1.0-120.0 mu M with the determination limits of 0.118 mu M and 0.134 mu M were obtained, respectively. The sensor was successfully applied to the detection of G and A in calf-thymus DNA with G/A ratio of 0.80. The facile preparation process and attractive sensing properties of the Cu-Ni@N,B-rGO nanocomposites made it a promising candidate for the development of advanced electrochemical sensor.