Pt-dispersed flower-like carbon nanosheet aggregation for low-overpotential electrochemical biosensing.

A Pt nanoparticle-decorated flower-like carbon nanosheet aggregation (FCNA) was prepared via one-step ethylene glycol method. The aggregation was characterized with scanning electron micrographs, X-ray photoelectron spectra, X-ray diffraction and electrochemical impedance spectra. When the aggregation was immobilized on a glassy carbon electrode, the dense dispersion of Pt nanoparticles (Pt NPs) on the carbon nanosheets of FCNA could combine the good conductivity of FCNA with the excellent catalytic activity of Pt NPs for the electroreduction of oxygen at a low overpotential, which led to a method for electrochemical detection of oxygen from 6.3 to 69.3 μM. Using glucose oxidase (GOx) as a model, the resulting GOx/Pt/FCNA nanocomposite-based amperometric biosensor showed a linear response to glucose ranging from 0.5 to 8.0 mM with a detection limit of 0.3 mM at a S/N ratio of 3. The designed biosensor was of excellent performance with high selectivity, acceptable recovery and good repeatability, and could be successfully applied in the detection of glucose in human serum. The FCNA could be expected as a carrier for the preparation of other metal nanoparticle-dispersed aggregations and biosensing applications.