Electrochemical determination of dopamine on a glassy carbon electrode based carbon nanoballs and carbon nanofiber

A facile method developed by modifying glassy carbon electrodes (GCEs) with a composite of carbon black nanoballs (CNBs) and carbon nanofiber (CNFs) is presented for the determination of dopamine (DA). The proposed platform (CNBs@CNFs/GCE) exhibited excellent catalytic activity towards DA. ΔEp was 391 mV, 110 mV and 27 mV at GCE, CNBs/GCE and CNBs@CNFs/GCE, respectively. The electrode yielded a pico-molar detection limit (LOD) of 335 pM. Interestingly, RSD of 15 consecutive scans of 1.0x10-8 M DA was 0.01% indicating excellent repeatability. The decrease in response of 1.0x10-8 M DA was 2.5% after 7 days indicating excellent stability of electrode. Repeatable and stable results make CNBs@CNFs/GCE of high interest for monitoring trace level of DA.