Real-time detection of residual antibiotics concentration with microwave cavity and planar EM sensors

To prevent the improper use of antibiotics in aquaculture and to assist the food safety law enforcement, this paper reports on assessing the feasibility of a bespoke electromagnetic (EM) wave sensing method for real-time in situ monitoring of residual antibiotic concentrations in water samples. For the first time the antibiotics solutions were tested in microwave cavity and in contact with planar sensor with interdigitated electrode (IDE) pattern on Rogers® substrate. Transmitted and reflected power signals were analysed in GHz frequency range and these were dependent on both: the type of antibiotic present in water and on its concentration.