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 elec-trode demonstrates excellent electrocatalytic activity for dopamine. Under the optimal parameters, the electrochemical sensor exhibits a wide detection range (0.05-90 mu M), a low limit of detection (9.3 nM, S/N = 3), and a high sensitivity (91.6 mu A mu M-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.