Size-controlled core-shell-structured Ag@carbon spheres for electrochemical sensing of bisphenol A

We report a facile strategy for preparing Ag nanoparticles with a carbon shell by hydrothermal method, and the effect of Ag source concentration on the resultant stability and sphere sizes was investigated. The field emission scanning electron microscopy and field emission transmission electron microscopy show that the sphere sizes range from 130 nm to 2 mu m with the gradual increase of Ag core and carbon shell simultaneously, energy dispersive spectrometry confirms the composition of core-shell-structured Ag@carbon, the face-centered cubic Ag phase is presented by X-ray diffraction analysis, and electrochemical impedance spectroscopy indicates that the conductivity of Ag@carbon changes with its sizes. Thereafter, a series of different sized Ag@carbon catalysts are used for the electrochemical sensing of bisphenol A (BPA). The results show that Ag@carbon sphere with a diameter of about 220 nm is a very effective and stable sensing material for the determination of BPA, which shows good prospects for sensor application.