Polythiophene/ZnO nanocomposite-modified glassy carbon electrode as efficient electrochemical hydrazine sensor

Abstract

An electrochemical approach was developed for rapid and effective detection of hydrazine using polythiophene (PTh)/ZnO nanocomposite modified glassy carbon electrode (GCE). The PTh/ZnO nanocomposite was synthesized by a modified sol-gel procedure using F127 structure directing mediator, followed by a chemical oxidative polymerization process. Cyclic voltammetry measurements using the PTh/ZnO modified GCEs revealed remarkable sensing response toward hydrazine compared to either bare GCE or pure ZnO, with diffusion-controlled electrode kinetics. Effective amperometric (i-t) response was achieved for the current modified electrodes, yielding a very rapid response time of <5s with a noticeable sensitivity of 1.22 μAμM−1cm−2 and a correlation coefficient (R2 = 0.9983) within a wide linear range of hydrazine concentration from 0.5 up to 48 μM. The limit of detection (LOD) calculated from the electrochemical measurements was found to be 0.207 μM at (S/N = 3), which is well below several earlier reports. Most significantly, the PTh/ZnO modified electrodes showed good operational stability, repeatability and reproducibility and allowed sensitive detection of hydrazine in the presence of several common interfering molecules. The results presented here provide real progress towards further realization of fabricating efficient hydrazine chemical sensors.