Amperometric and Impedimetric Determination of Hydrazine at a Novel Trimethine Cyanine Dye Film Modified Glassy Carbon Electrode

摘要

In this study, we report the amperometric and impedimetric determination of hydrazine at a noveltrimethine cyanine dye, 1H-Benz[e]indolium, 2揫33揵utyl, 3ihydro, 1imethylH- benz[e]indol搚lidene)ropenyl], 1, 3rimethyl hexafluorophosphate (DVD-R dye A4) or(DVDR) film modified glassy carbon electrode (GCE). The DVDR film was electrochemicallydeposited on a GCE surface by performing 20 consecutive cyclic voltammograms at the scan rate of-1 100 mV s in the potential range between -0.8 and 2.0 V in 0.1 mM DVDR in 0.1 M H2SO4 solution.The SEM and AFM results revealed that DVDR film surface possess both flake and bead likestructures. Cyclic voltammetry (CV) results demonstrated that DVDR film was electrochemicallyactive and it showed a pair of well-defined redox peaks at a formal potential (E of 5.5 mV in pH 7.Electrochemical impedance spectroscopy (EIS) results showed that rapid electron transfer processoccurs at the DVDR/GCE surface than the bare/GCE surface. The electron transfer resistance (Ret)values obtained at the DVDR film increased linearly with increase in hydrazine concentrationsbetween 0.05 mM.07 mM, which confirmed the excellent impedimetric hydrazine quantification.The DVDR film showed rapid amperometric i-t response towards hydrazine in the linear concentration -1 -2range between 1 x 10 M.22 x 10 M with a sensitivity of 0.571 A M cm of hydrazine. Eventhough large amounts (1000/500揻old) of the common cations/anions coexist in the same supportingelectrolyte, they do not produce any notable interference effect with the hydrazine oxidation signal,which validates the high selectivity of DVDR film for hydrazine. Moreover, acceptable recovery wasachieved at the DVDR/GCE in hydrazine spiked various water samples, which confirmed the practicalapplicability of the developed sensor.