Highly Sensitive Acetylcholinesterase Biosensor Based on Shaped Controlled ZnO Nanostructure for Paraoxon Pesticide Detection

Zinc oxide (ZnO) is an attractive material that finds applications in areas ranging from transistors, varistors, solar cells, photocatalysts and biosensors. Here we report the electrodeposition of ZnO nanostructured thin films in the presence of various capping agents like potassium chloride, ammonium fluoride and ethylenediamine to form different morphologies of ZnO. These ZnO nanostructures were used as biosensing platforms for the immobilization of acetylcholinesterase (AChE) and detection of the pesticide paraoxon. The electrodeposition of ZnO nanostructures was performed on carbon paper and carbon fabric substrate by using a zinc nitrate (Zn(NO3)2) precursor at 70 °C temperature with an applied potential of -1.0 V and 30 min reaction time. Many different morphologies of ZnO such as nanorods, nanoneedles, nanoplatelets, nanoflowers were successfully synthesized and characterized using scanning electron microscopy (SEM). Further the ZnO nanostructures were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy, Raman spectroscopy and electrochemical impedance spectroscopy (EIS). An amperometric current response for the detection of paraoxon was recorded. The biosensor shows a detection limit to paraoxon in the range of 1nM–5µM . The developed biosensor shows high sensitivity, stability and low cost. [PS[E1]Detection limit should be 1 nM. Let us not write a range. It can be confusing. [PS[E2]You have written the abstract very well. Good job!