▎ 摘　　要

Gold interdigitated microelectrodes (Au-IDA) modified with either graphene flakes exfoliated using flavin mono nucleotide (FMN) (Gr-FMN) or graphene flakes and platinum nanoparticles (Pt-Gr-FMN) have been studied in the oxidation of uric add (UA). An electrochemical method for the detection and quantification of UA in phosphate buffer solution at physiological pH (PBS, 0.25 M, pH 7) in the absence and presence of ascorbic add (AA) has been studied by cyclic voltammetry. The quantification of UA was investigated by cyclic voltammetry, presenting an oxidation peak at 0.99 V with both modified electrodes. Linearity range of 60-578 mu M and 60345 mu M has been found for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA electrodes, respectively. Limits of detection of 18 M were obtained for both electrodes, and the repeatability was studied at 177 mu M providing 4% and 8% for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA, respectively. AA interference has been studied by cyclic voltammetry, showing two clearly separated oxidation peaks, at 0.99 V for UA oxidation and at 0.74 V for Gr-FMN/Au-IDA and 0.70 V for Pt-Gr-FMN/Au-IDA for AA oxidation. Linearity range has been studied in presence of 250 mu M AA obtaining a working range of 60-578 mu M for Gr-FMN/Au-IDA electrode and of 60-288 mu M with Pt-Gr-FMN/Au-IDA electrode. Limits of detection remain at 18 mu M for both electrodes and the repeatability was studied at 177 mu M providing 8% and 14% for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA electrodes respectively. (C) 2016 Elsevier B.V. All rights reserved.