In this paper, NiCo-X (X = OH, S, P, Se) nanodiscs (NDs) were synthesized. Firstly, nickel-cobalt hydroxide (NiCo-OH) precursors with a nanodisc-like structure were prepared by a hydrothermal method. In the next step, nickel-cobalt sulfide nanodiscs (NiCo-S NDs), nickel-cobalt selenide nanodiscs (NiCo-Se NDs), and nickel-cobalt phosphide nanodiscs (NiCo-P NDs) were obtained from the synthesized NiCo-OH NDs in the previous step. The NiCo-Se NDs and NiCo-P NDs were prepared by selenization and phosphidation processes of the NiCo-OH NDs in a tube furnace containing a N2 atmosphere. The electrocatalytic performance of the mentioned nanodiscs is compared in the electrochemical determination of isoprenaline (IP) as a template. The results showed that the NiCo-Se NDs show better electrocatalytic activity compared to the other nanodiscs studied. The NiCo-Se ND-modified glassy carbon electrode (NiCo-Se NDs/GCE) showed a low detection limit (0.16 μM) and wide linear range (0.5−750 μM) of IP. The proposed substrate was successfully used for measuring IP in human blood serum samples. This study provides insights into the development of polymetallic nanodiscs in the field of electrochemical applications. In addition, our results are promising for usage in other electrochemical applications
