Structural Engineering of Hollow Microflower-like CuS@C Hybrids as Versatile Electrochemical Sensing Platform for Highly Sensitive Hydrogen Peroxide and Hydrazine Detection

Designing metal sulfides with unique configurations and exploring their electrochemical activities for hydrogen peroxide (H 2 O 2 ) and hydrazine (N 2 H 4 ) is challenging and desirable for various fields. Herein, hollow microflower-like CuS@C hybrids were successfully assembled and further exploited as a versatile electrochemical sensing platform for H 2 O 2 reduction and N 2 H 4 oxidation, of which the elaborate strategies make the perfect formation of hollow architecture, providing considerable electrocatalytic sites and fast charge transfer rate, while the appropriate introduction polydopamine-derived carbon skeleton facilitates the electronic conductivity and boosts structural robustness, thus generating wide linear range (0.05–14 and 0.01–10 mM), low detection limit (0.22 μM and 0.07 μM), and a rather low overpotential (−0.15 and −0.05 V) toward H 2 O 2 and N 2 H 4, as well as good selectivity, excellent reproducibility, and admirable long-term stability. It should be highlighted that the operating potentials can compare favorably with those of some reported H 2 O 2 and N 2 H 4 sensors based on noble metals. In addition, good recoveries and acceptable relative standard deviations (RSDs) attained in serum and water samples fully verify the accuracy and anti-interference capability of our proposed sensor systems. These results not only elucidate an effective structural nanoengineering strategy for electroanalytical science but also advance the rational utilization of H 2 O 2 and N 2 H 4 in practicability.