Chemical sensors based on Molecularly Imprinted Conductive Polymers for the detection of antibiotics

Antibiotics are increasingly used to treat certain bacteria that are harmful to humans. However, their inadequate or excessive use can lead to the proliferation of certain more resistant strains, which ultimately reduces their effectiveness. To counter this, it is essential to limit the amount of antibiotics ingested, particularly through animal food, if the animals themselves have received antibiotic treatment. In the case of milk, it is necessary to be able to detect quantities of antibiotics in the range of a few parts per billion. A sensor has therefore been developed for this purpose. This sensor is based on the measurement of the variation in conductivity of a sensitive layer deposited between two electrodes, which is influenced by the presence of the antibiotic. It is in this sensitive layer that the innovative aspect of this project lies, namely the use of a molecularly imprinted polymer that allows a very specific interaction with the antibiotic to be detected, associated with a semiconductor polymer whose conductivity can be modified by the interaction with the antibiotic. The synthesis and measurement conditions were therefore experimentally optimised by selecting the sensors that gave the best results. Optimisations of these conditions were also carried out in a predictive way thanks to a molecular dynamics software allowing to observe the interactions taking place between the different molecules used. The physical phenomena that may occur during detection were also deduced from the experimental results. Although it seems possible to further improve the performance of these sensors, their use in this field seems very promising considering the obtained results.