A novel non-enzymatic zinc oxide thin film based electrochemical recyclable strip with device interface for quantitative detection of catechol in water.

Catechol, one of the major effluents released by various chemical and metal processing industries, causes severe pollution of groundwater. Monitoring of catechol in water using cost-effective, handheld sensor is demanding for the safety of the environment. In this work, non-enzymatic zinc oxide thin film based electrochemical strip sensor is developed on conducting glass substrate for detection of catechol. The preparation of strip without employing standard Pt or Ag/AgCl electrodes and simply depositing ZnO through wet chemical process represents a cost-effective innovative technique. The ZnO thin film is characterized using field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM) and grazing incidence X-ray diffractometer (GIXRD). Catechol is electrochemically detected by means of cyclic voltammetry and amperometry. A prominent redox peak of the developed strip attributed to the detection of catechol is observed at -0.26 V in cyclic voltammetry. The strip is integrated with readout meter and an algorithm is built based on the experimentally observed linear variation of amperometric current with catechol concentration. The quantitative detection performance is demonstrated by testing 0.1-12 ppm catechol solutions.