Electrodeposition of palladium nanoparticles on porous graphitized carbon monolith modified carbon paste electrode for simultaneous enhanced determination of ascorbic acid and uric acid

•Palladium nanoparticles deposited on carbon monolith modified carbon paste electrode (PdNPs/CM/CPE) was successfully fabricated.•The PdNPs/CM/CPE could simultaneously separate and detect AA and UA signals into two well-defined voltammetric peaks.•The PdNPs/CM/CPE has demonstrated low detection limits.•The PdNPs/CM/CPE achieved good reproducibility with stable electrochemical responses observed.

A novel, simple and highly sensitive electrochemical method is developed for the determination of ascorbic acid (AA) and uric acid (UA) based on a palladium nanoparticles deposited on porous graphitized carbon monolith modified carbon paste electrode (PdNPs/CM/CPE). The chemical modified electrode was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The PdNPs/CM/CPE displayed excellent electrochemical catalytic activities toward AA and UA with bare CPE, PdNPs/CPE, CM/CPE and PdNPs/CM/CPE by cyclic voltammetry (CV). The oxidation potentials of AA and UA at the PdNPs/CM/CPE shifted negatively and the peak currents were much larger than other electrodes. The amperometric signal of PdNPs/CM/CPE showed a good linearity with correlation coefficient greater than 0.997. The low detection limits (S/N = 3) for AA and UA were 0.53 μmol L−1 and 0.66 μmol L−1, respectively. The proposed method showed easy fabrication, high sensitivity and stability, and good reproducibility. In addition, the modified electrode was applied to determine the AA and UA in human serum sample.