In this work, we report the biosynthesis of CuCo2S4 nanoparticles (Bio‐NPs) via hydrothermal method. The synthetized Bio‐NPs‐CuCo2S4 was studied as an active material of working electrode for electrochemical supercapacitor and non‐enzymatic hydrazine sensor. The Bio.NPs‐CuCo2S4/ITO electrode has a specific capacitance of 264 F/g at a current density of 1 A/g. Meanwhile, the electrode exhibits excellent electrochemical performances, such as an energy density of 33 Wh/Kg and a power density of 900 W/Kg. The Bio.NPs‐CuCo2S4/ITO electrode for non‐enzymatic hydrazine sensor exhibits a very high sensitivity of 2400 μA.mM−1.cm−2, a wide linear range from 0.001 to 1.400 mM and shows an excellent selectivity.

In this work we report an easy and efficient way to fabricate nanostructured cobalt oxide (Co3O4) thin films as a non‐enzymatic sensor for H2O2 detection. Co3O4 thin films were grown on ITO glass substrates via the sol‐gel method and characterized with several techniques including X‐ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical absorbance. The Co3O4 thin films’ performance regarding hydrogen peroxide detection was studied in a 0.1 M NaOH solution using two techniques, cyclic voltammetry (CV) and amperometry. The films exhibited a high sensitivity of 1450 μA.mM−1.cm−2, a wide linear range from 0.05 μM to 1.1 mM, and a very low detection limit of 18 nM. Likewise, the Co3O4 thin films produced showed an exceptional stability and a high selectivity.