Synthesis of Cu–Co bimetallic nanoparticles using TiN-coated electrodes for glucose-sensing applications

Abstract

This study focuses on the synthesis of Cu–Co bimetallic nanoparticles (NPs) by electrodeposition on conductive TiN-coated electrodes for nonenzymatic glucose-sensing applications. By changing the (Cu/Co)sol. ratio in electrolytes, the atomic concentrations and particle sizes of the Cu–Co NPs over the TiN-coated substrates were tailored. It was easier to incorporate Cu (which exhibits a higher reduction potential) into the NPs than Co. The bimetallic features of Cu–Co NPs were verified by investigating the energy-dispersive spectroscopy/field-emission scanning electron microscopy and field-emission transmission electron microscopy high-resolution images with the corresponding fast Fourier transform patterns. Even a small amount of bimetallic Cu–Co NPs greatly enhanced the detection sensitivity of glucose because of both the synergistic and nanosize effects. At a [Cu/(Cu+Co)]sol. concentration ratio of 0.5, the glucose sensitivity of the obtained Cu–Co NPs with particle sizes of 50 ± 14 nm reached 1602 ± 92 μA cm−2 mM−1, which is much higher than that of the monometallic Cu or Co NPs and lies in the medium–high regime of reported values from the literature.