Smart sensing for antibiotic monitoring in mineral and river water: development of an electronic tongue device

Sensors are considered the future monitoring tools since compared to traditional sampling and analysis techniques, provide fast response on the output data in a timely, continuous, safe, and cost-effective fashion. Within sensors, the electronic tongue (e-tongue) devices are gaining special attention for liquid matrices. The use of nanomaterials to perform the analysis as sensor’s layers improves the device’s sensitivity and performance, due to their unique physical and chemical properties, such as more conductivity and/or resistivity to the changes in the target analyte, high relative surface area and size versatility.

Thus, the aim of the present work was to explore the potential of the e-tongue concept to monitor Clarithromycin (10 ng/L to 10 ug/L) by various nanostructures ( e.g. polyethyleneimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS), MWCNTs) for coating, in order to find the best combination to detect and quantify the target contaminants in different matrices. Two thin-film deposition techniques were performed: layer-by-layer and sputtering techniques. The detection of the target antibiotics was achieved by measuring the impedance spectra of thin-films when immersed in mineral and river water matrices. The impedance spectra will be accessed with a Solartron 1260 Impedance Analyzer in the frequency range of 1 Hz to 1 MHz, by applying 25 mV. The sensor devices array forming the e-tongue concept, consist of ceramic/glass BK7 solid support with deposited gold interdigitate electrodes, coated with the thin films aforementioned.