An electrochemical sensor for dopamine based on polydopamine modified reduced graphene oxide anchored with tin dioxide and gold nanoparticles

摘要

In the present work, polydopamine (PDA) modified reduced graphene oxide (pRGO)/SnO2/Au nanoparticles (NPs) were synthesized. SnO2/AuNPs were prepared through the redox reaction between reductive stannous(II) ions and oxidative auric(III) ions without any other reagents, and then the as-prepared graphene oxide (GO) was reduced and stabilized with the help of DA followed by decorating with SnO2/AuNPs. The morphology and structure of the hybrid nanomaterials were characterized by Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction analysis. Then we constructed electrochemical sensors based on the hybrid nanomaterials for the determination of dopamine (DA). Cyclic voltammetry (CV) results showed that the hybrid nanomaterials had better sensing performance than pRGO/AuNPs and pRGO. Differential pulse voltammetry (DPV) showed that the separation of oxidation peak potentials for ascorbic acid (AA)-DA, uric acid (UA)-DA and UA-AA was about 200 mV, 100 mV and 300 mV, respectively. The linear range for the detection of DA was from 0.008 mu M to 20 mu M with a coefficient of 0.9986. The detection limit was 5 nM (S/N = 3). These indicate the selective and sensitive detection of DA. Finally, the constructed sensors were also applied to detect DA in human real samples.