Synergetic signal amplification based on electrochemical reduced graphene oxide-ferrocene derivative hybrid and gold nanoparticles as an ultra-sensitive detection platform for bisphenol A

In this paper, a novel electro-active graphene oxide (GO) nanocomposite was firstly prepared by covalently grafted (4-ferrocenylethyne) phenylamine (Fc-NH₂) onto the surface of GO. The synthesized hybridized nanocomposite of GO-Fc-NH₂ coupled with HAuCl₄ simultaneously electrodeposited on the glassy carbon electrodes (GCE) to obtain rGO-Fc-NH₂/AuNPs/GCE. The covalently grafted material of the rGO-Fc-NH₂/AuNPs film can effectively prevent the electron mediator leaking from the electrode surface, which can hold the advantage of both the nanomaterials and electron mediator. By employing the catalysis effect of the nanomaterial and electron mediator coupling with large active surface area and high accumulation capacity of rGO-Fc-NH₂/AuNPs, a synergetic signal amplification platform for ultra-sensitive detection of bisphenol A (BPA) was successfully established. With this novel sensor, the oxidation peak currents of BPA were linearly dependent on the BPA concentrations in the range of 0.005–10 μM with the detection limit of 2 nM. Modification of electron mediators on nanomaterials can greatly enhance the electrochemical performance of the sensors and will provide a new concept for fabricating newly electro-active nanomaterials-based electrochemical biosensors.