ZnO/α-MnO2 hybrid 1D nanostructure-based sensor for point-of-care monitoring of chlorinated phenol in drinking water

Abstract

Herein, we have reported a highly selective electrochemical sensing of 2,4-dichlorophenol in water at room conditions. 1D hybrid nanostructure of ZnO/α-MnO2 nanowire by combining ZnO nanoparticles and α-MnO2 nanowire was developed using a facile ultrasound induced coprecipitation method. The developed hybrid nanostructured material has been characterized in detail using X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, which confirm a successful synthesis of the ZnO/α-MnO2 hybrid 1D nanostructure. A nano-enabled, label-free electrochemical sensor is fabricated by utilizing the synthesized ZnO/α-MnO2 hybrid 1D nanostructure on a printed contacts-based working electrodes. The sensor prominently showed high sensitivity (0.45 kΩ/nM/mm2) with an excellent limit of detection of 2 nM. The equivalent Randel circuit has been designed and modeled for understanding the evolution of electron transfer kinetics. The shelf life analysis of the fabricated sensor device revealed the stability and reproducibility of over 90 days. The sensor is found to be highly selective toward 2,4-dichlorophenol even in the presence of other organic compounds. The developed sensor provides a novel, fast, and economical approach to detect chlorinated phenolic pollutants in water at ambient conditions, beneficial for health and environmental safety.