A high-performance voltammetric sensor based on Co/Ni-metal-organic framework modified electrode for the determination of dopamine in the presence of tyrosine.

BACKGROUND AND PURPOSE: The central nervous, renal, hormonal, and cardiovascular systems depend on dopamine. Therefore, a straightforward, sensitive, and selective method for detecting DA is needed to track DA levels in the human body. EXPERIMENTAL APPROACH: Co/Ni-metal-organic framework was developed via a one-pot hydrothermal synthesis. The electrochemical sensor developed for dopamine measurement used Co/Ni-metal-organic framework materials on screen-printed carbon electrodes. The Co/Ni-metal-organic framework on a screen-printed carbon electrode exhibits excellent electrocatalytic activity for dopamine oxidation, owing to its high electron-transfer rate. KEY RESULTS: The electrocatalytic activity of Co/Ni-metal-organic framework on a screen-printed carbon electrode significantly improves dopamine oxidation, yielding higher peak currents and lower oxidation potentials than the bare screen-printed carbon electrode. The sensor detected dopamine with a linear response, ranging from 0.01 to 660.0 μmol L-1, with a limit of detection of 0.007 μmol L-1. To measure tyrosine and dopamine simultaneously, differential pulse voltammetry was used. The separation between tyrosine and dopamine reached 150 mV. CONCLUSION: Successful target-analyte identification using the proposed voltammetric sensor was achieved, detecting both dopamine and tyrosine in actual sample tests.