Prussian Blue Analogue-Derived Iron Sulfide–Cobalt Sulfide Nanoparticle-Decorated Hollow Nitrogen-Doped Carbon Nanocubes for the Selective Electrochemical Detection of Dopamine

Hollow nanostructures have gained much attention in the electroanalytical field. This work describes the synthesis of CoS2–FeS2 nanoparticle-decorated hollow nitrogen-doped carbon nanocubes (CoS2–FeS2/HNCC) by a direct sulfidation of the Co–Fe Prussian blue analogue at a high temperature. By integrating dual-phase metal sulfides and a nitrogen-doped carbon matrix, this hollow nanocubic structure provides rich catalytic centers, enhanced conductivity, large surface area, and 3D-porous channels, which all contribute to the adsorption and catalysis of dopamine. The CoS2–FeS2/HNCC-modified glassy carbon electrode demonstrates excellent electrocatalytic activity for dopamine. Under the optimal parameters, the electrochemical sensor exhibits a wide detection range (0.05–90 μM), a low limit of detection (9.3 nM, S/N = 3), and a high sensitivity (91.6 μA μM–1 cm–2) along with excellent selectivity, reproducibility, reusability, and stability. This method has also been applied for the detection of dopamine in human urine samples and displays satisfactory results.