Gold-doped nano-perovskite-decorated carbon nanotubes for electrochemical sensing of hazardous hydrazine with application in wastewater sample

[Display omitted] •Sr22Pd0.7Au0.3O3/CNT composite is drop cast on GC to form effective/simple hydrazine sensor.•Doping the Sr-Pd perovskite with gold was crucial to the remarkable performance of the sensor.•The HH oxidation potential over the sensor is +95mV versus +460mV over GC/CNT electrode.•Within 0.007–90 μM concentration range the sensor DL for hydrazine in wastewater was 0.261nM.•The sensor is highly resistant to common organic and ionic interfering species and can be stored for four weeks. We report one pot preparation of an Au-doped Sr-Pd-perovskite (Sr2Pd0.7Au0.3O3) carbon nanotubes (CNTs) composite. A thin layer of the composite is formed by drop-cast over a glassy carbon (GC) surface and applies for electrochemical sensing of hydrazine hydrate (HH). For the proposed sensor, current-signal responses for HH oxidation mount 24 and 11 times compared to GC and GC/CNT electrodes, respectively. The HH conversion process is thermodynamically more favored over the sensor surface with oxidation potential value of +95 mV versus a value of +460 mV over GC/CNT electrode. Doping the Sr-Pd perovskite with gold is crucial to the remarkable performance of the sensor. Conductive Au3+ ions inclusion within the crystal lattice create more oxygen-vacancies that stabilize the perovskite structure and enhance both its electronic and ionic conductivities. The practical performance of the sensor is evaluated by amperometry quantification of HH in wastewater sample for a wide concentration range of (0.007–90 μM) and a low detection limit of 0.261 nM in the low concentration range (0.007–1 μM). The GC/(CNT-Sr2PdAuO3) sensor response is stable for one month with excellent anti-interference ability towards common interfering species.