An innovative design of hydrazine hydrate electrochemical sensor based on decoration of crown ether/Nafion/carbon nanotubes composite with gold nanoparticles

For the first time an efficient electrochemical sensor is presented for electrochemical sensing of hydrazine hydrate (HH) in real water samples. A layer-by-layer stacked composite sensor is fabricated based on carbon nanotubes (CNTs), Nafion (NF), 15-crown-5 (CW) and gold nanoparticles; GC/CNT/NF/CW/Aunano. Each of the sensor components? unique property contributes in synergism to the current signal enhancement. CNTs offer large surface area, and good electrical conductivity; NF has a great cationic selectivity which facilitates the preconcentration of HH; crown ether allows good binding ability, stable supramolecular complexes, and excellent host?guest interaction. Besides, the presence of Aunano over the electrode composite surface provides large electroactive surface for HH oxidation process. Thermodynamically the conversion process of HH is more preferred over the composite sensor surface with oxidation potential value of + 135 mV against a value of + 630 mV over GC/CNT electrode. Amperometry determination of HH in wastewater sample in the concentration range (0.005?200 ?M) is successfully achieved with low detection limit (0.132 nM) in the low concentration range. Practical application of the GC/CNT/NF/CW/Aunano sensor is efficiently assessed in wastewater sample for HH determination with acceptable recovery, excellent anti-interference ability and long-term stability.

Automated summary

An efficient electrochemical sensor has been developed for the detection of hydrazine hydrate in real water samples by utilizing a composite sensor with unique properties of carbon nanotubes, Nafion, 15-crown-5, and gold nanoparticles. The sensor allows for successful detection of HH in a concentration range of 0.005-200 μM with a low detection limit. The practical application of the sensor in wastewater analysis demonstrates acceptable recovery, excellent anti-interference ability, and long-term stability.