LAUSR

A highly sensitive amperometric hydrazine monitoring sensor offering an ultrawide dynamic range of 5 µM to 1 M in alkaline media (e.g., 1 M KOH) was developed via co-electrodepositing an iridium-nickel alloy nanoparticles (NPs) functionalized with multi-walled carbon nanotubes (Ir-Ni-MWCNT) on a disposable screen-printed carbon electrode. The synergistic interaction of MWCNT with Ir-Ni alloy NPs resulted in enlarging the active surface area, and assisting both rapid electron transfer, and alkaline media stability with an onset potential of -0.12 V (vs. Ag/AgCl) toward hydrazine oxidation. A limit of detection for hydrazine was 0.81 µM with guaranteed reproducibility, repeatability, and storage stability alongside a superb selectivity toward ethanolamine, urea, dopamine, NaBH4, NH4OH, NaNO2, and Na2CO3. Our sensor was finally applied to on-site monitoring of the carbon-free hydrazine concentration at the anode and cathode of a hydrazine fuel cell, providing more insight into the hydrazine oxidation process during cell operation.