Electrochemical sensor based on nitrogen doped graphene: Simultaneous determination of ascorbic acid, dopamine and uric acid

Nitrogen doped graphene (NG) was prepared by thermally annealing graphite oxide and melamine mixture. After characterization by atomic force microscopy and X-ray photoelectron spectroscopy etc., the electrochemical sensor based on NG was constructed to simultaneously determine small biomolecules such as ascorbic acid (AA), dopamine (DA) and uric acid (UA). Due to its unique structure and properties originating from nitrogen doping, NG shows highly electrocatalytic activity towards the oxidation of AA, DA and UA. The electrochemical sensor shows a wide linear response for AA, DA and UA in the concentration range of 5.0 × 10−6 to 1.3 × 10−3 M, 5.0 × 10−7 to 1.7 × 10−4 M and 1.0 × 10−7 to 2.0 × 10−5 M with detection limit of 2.2 × 10−6 M, 2.5 × 10−7 M and 4.5 × 10−8 M at S/N = 3, respectively. These results demonstrate that NG is a promising candidate of advanced electrode material in electrochemical sensing and other electrocatalytic applications.

Due to its particular structure and electronic properties originating from nitrogen doping, nitrogen doped graphene prepared by thermally annealing graphite oxide with melamine shows high electrocatalytic activity towards the oxidation of ascorbic acid, dopamine and uric acid. A novel NG-based electrochemical sensor has been fabricated and successfully used to simultaneously determine these biomolecules with high sensitivity and selectivity.Figure optionsDownload as PowerPoint slideHighlights
► Nitrogen doped graphene (NG) prepared thermally using melamine precursor.
► NG shows highly electrocatalytic activity toward small biomolecules.
► The electrocatalytic activity depends on the doped nitrogen amount.
► NG based electrochemical biosensor detects ascorbic acid, uric acid and dopamine with high sensitivity and selectivity.