Detection of Zn in water using novel functionalised planar microwave sensors

Abstract

Metal pollution in aquatic environments has attracted global attention. Current methods are not able to monitor water quality in-situ at low-cost. This paper reports on a novel approach for detecting changes in the concentration of zinc in water using electrical and a microwave sensor method, adopting two planar sensors: one was functionalised with a screen-printed β-Bi2O3 based coating, while the other was uncoated. Results show that both electrical and the microwave sensor responses were dependent on the presence and concentration of Zn in water with R2 = 0.93–0.99. The functionalised sensor with a 60 μm thick β-Bi2O3 based film offers improved performance compared with both uncoated and functionalised sensors with 40 µm thick coating for detecting the changes of Zn concentrations in water for low levels (100 and 500 µg/L). This novel sensing system could be a cost-effective alternative to the current offline methods.