Three-dimensional Au nanoparticles@UiO-66 shell-coated carbon cloth electrode for high-performance electrochemical sensing of hydrazine

[Display omitted] •In situ solvothermal growth of UiO-66 on carbon cloth substrates and in situ deposition of Au nanoparticles in UiO-66 shells.•The Au nanoparticles@UiO-66/carbon cloths electrode has large specific surface area and high electron transfer efficiency.•The confinement of Au nanoparticles within UiO-66 shells enhances their catalytic activity and stability.•Excellent electrochemical sensing performance for hydrazine in terms of extensive linear ranges, high sensitivity and ultra low limits of detection and quantification.•Exceptional sensing selectivity due to the ordered channels of the UiO-66 shell. A high-performance electrochemical sensing system for hydrazine is demonstrated based on a three-dimensional (3D) carbon cloth (CC) electrode coated by a composite film of Au nanoparticles@UiO-66 (Au NPs@UiO-66/CC). The Au NPs@UiO-66/CC electrode was prepared by solvothermal synthesis of a UiO-66 film on a carboxyl-functionalized CC electrode and subsequent in situ electrodeposition of Au NPs inside the UiO-66 film using periodic galvanostatic pulse currents. This in situ preparation approach significantly enhances the electrical interaction between the Au NPs@UiO-66 shell and the CC substrate while preserving the electrochemical activity of the Au NPs@UiO-66/CC electrode. Owing to large specific surface area and high electron transfer efficiency, the Au NPs@UiO-66/CC electrode has exceptional electrochemical sensing performance for hydrazine, showing two extensive linear ranges (3 μM–1 mM, 1–9 mM), high sensitivity (1234.6, 617.3 μA mM−1 cm−2) as well as extremely low limits of detection (0.0035 μM) and quantification (0.0116 μM). Moreover, the Au NPs@UiO-66/CC electrode shows great sensing selectivity since the ordered channels of the UiO-66 shell restrict the access of larger interferents to the active Au NPs inside. Finally, as proof-of-concept, our Au NPs@UiO-66/CC electrode shows reliable performance in the determination of hydrazine in various water samples.