Study of chemical and biochemical optical fiber sensors based on molecularly imprinted polymers

Description

The research subject deals with the study of chemical and biochemical sensors on optical fibers exploiting sensitive coatings based on Molecularly Imprinted Polymers. In brief, Molecularly Imprinted Polymers are obtained from a polymerization initiated in the presence of a chosen template molecule that will be extracted afterwards. This process creates a series of cavities in the polymer matrix with affinity to the prior molecule. These polymers can be synthesized as powders or films. They provide a highly selective adsorption towards the target molecule according to a “key-lock” mechanism and are used for filtration, chromatography and chemical detection. Chemical detection with optical fibers is based on the modification of the refractive index of the polymer matrix deposited on the fiber during the adsorption of the target. The optical fiber plays the role of transducer (transformation of the chemical signal to an optical signal) and transporter of the information. This kind of sensor may be used in the medical field for in situ diagnostics (fibers possess a very small diameter) or, on the contrary, for distributed measurements on long distances.