Design of a hybrid optical component for the early detection of plant diseases

The project to which this work relates aims to propose an integrated infrared optical solution to meet the current objective of reducing the use of phytosanitary inputs in agriculture. Its main objective is to prove the feasibility of hybrid optical micro-sensors that will allow early detection of plant diseases, via the detection of spores of phytopathogenic fungi. The innovation produced should make it possible to avoid systematic preventive treatments, thanks to a better targeted decision support. Due to their transparency in the infrared range where many absorption lines of spores are located, chalcogenide glasses are materials of choice for the realization of biosensors. The specific functionalization of the chalcogenide waveguides and the multivariate analysis of the spectral measurements will make it possible to increase the sensitivity of the probes and make them selective regarding the different types of spores and to discriminate any other element detected (pollen, dust for example). We are thus currently interested in the functionalization of activated GeSeTe thin layers with monosilylated functional groups. The advantage of sol-gel chemistry is that it allows multi-functionalization in a single step. In the context of spore detection, which generally involves several sites, the immobilization of several functions is therefore be studied.