Nitrogen-doped carbon frameworks decorated with palladium nanoparticles for simultaneous electrochemical voltammetric determination of uric acid and dopamine in the presence of ascorbic acid.

A glassy carbon electrode (GCE) was modified with nitrogen-enriched carbon frameworks decorated with palladium nanoparticles (Pd@NCF/GCEs). The modified GCE is shown to be a viable tool for determination of uric acid (UA) and dopamine (DA) in the presence of ascorbic acid (AA). The Pd@NCF was fabricated though one-step pyrolysis and characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and nitrogen-adsorption/desorption analysis. The Pd@NCF/GCE was characterized by differential pulse voltammetry (DPV). Both UA and DA have pronounced oxidation peaks (at 360 mV for UA and 180 mV for DA, all vs. Ag/AgCl) in the presence of AA. Response is linear in the 0.5-100 μM UA concentration range and in the 0.5-230 μM DA concentration range. The detection limits are 76 and 107 nM, respectively (at S/N = 3). This electrode is stable, reproducible and highly selective. It was used for UA and DA determination in spiked serum samples. Graphical abstractSchematic representation of nitrogen-enriched carbon frameworks decorated with palladium nanoparticles co-modified glassy carbon electrode for simultaneous determination of dopamine and uric acid in the presence of ascorbic acid.