Fabrication of Hollow Carbon Sphere@Au By Pyrolyzing Polystyrene@Polydopamine@Au As a Highly Efficient Electrocatalyst for Biosensing Application

Abstract

We demonstrate a facile approach to fabricate an electrocatalyst consisting of Au encapsulating a hollow carbon microsphere (HCMS@Au) for the detection of uric acid (UA), dopamine (DA), and ascorbic acid (AA). The HCMS@Au is obtained by the pyrolysis of polystyrene@polydopamine@Au (PS@PDA@Au) microspheres. Electrochemical methods including potentiostatic mode and pulse voltammetric scans are employed to identify relevant redox signals for UA, DA, and AA. The HCMS@Au reveals a lower detection limit for DA in the ambiance of AA and UA. We attribute the Au nanoparticles with high electric conductivity and uniform size that are distributed conformally on the hollow carbon microspheres for the enhanced detection sensitivity. The morphology and composition of HCMS@Au are analyzed by scanning electron microscope, transmission electron microscope, and energy dispersive spectroscope.