Gold nanoparticles coated polystyrene/reduced graphite oxide microspheres with improved dispersibility and electrical conductivity for dopamine detection

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2013-12, Vol.112, p.310-314
• Main Authors: Qian, Tao, Yu, Chenfei, Wu, Shishan, Shen, Jian
• Format: Article
• Language: English
• Subjects: Ascorbic Acid - analysis; Biosensor; citrates; Coating; colloids; detection limit; Dispersibility; Dopamine; Dopamine - analysis; Electric Conductivity; electrical conductivity; Electrochemical Techniques - methods; electrochemistry; electrodes; enzymes; Gold; Gold nanoparticles; graphene; Graphite - chemistry; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Microscopy, Electron, Transmission; Microspheres; nanogold; Nanoparticles; nucleic acids; Oxidation-Reduction; Oxides; Polystyrene; Polystyrene resins; Polystyrenes; proteins; Reduced graphite oxide; Resistivity; Uric Acid - analysis
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2013.08.005

•A novel strategy to improve the sensitivity of graphene polymer composite sensors was proposed.•Gold nanoparticles coated PS/reduced graphite oxide (AuNPs@PS/RGO) microspheres were facilely prepared.•AuNPs@PS/RGO microspheres offered a nanomole level detection limit for DA with excellent sensitive and selective.•AuNPs@PS/RGO microspheres dispersed more homogeneously and stably in water comparing with graphene sheets and PS/graphene microspheres. Gold nanoparticles coated polystyrene/reduced graphite oxide (AuNPs@PS/RGO) microspheres have been successfully prepared via a facile process, and the decorative gold nanoparticles could prevent the aggregation of RGO by electrostatic repulsive interaction, and lead to high dispersibility of the composite. The prepared composite has a highly increased conductivity of 129Sm−1 due to the unique electrical properties of citrate reduced gold nanoparticles. Being employed as an electrochemical sensor for detection of dopamine, the modified electrode exhibits remarkable sensitivity (3.44μA/μM) and lower detection limit (5nM), with linear response in a range of 0.05–20μM. Moreover, valid response to dopamine obtained in present work also indicates the prospective performances of AuNPs@PS/RGO microspheres to other biological molecules, such as nucleic acids, proteins and enzymes.