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 (H2O2) and hydrazine (N2H4) 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 H2O2 reduction and N2H4 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 H2O2 and N2H4, 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 H2O2 and N2H4 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 H2O2 and N2H4 in practicability.