The use of optical fibers as sensing element is increasing in clinical, pharmaceutical and industrial applications.
Excellent light delivery, long interaction length, low cost and ability not only to excite the target molecules but also to
capture the emitted light from the targets are the hallmarks of optical fiber as biosensors. In biosensors based on fiber
optics the interaction with the analyte can occur within an element of the optical fiber. One of the techniques for this kind
of biosensors is to remove the fiber optic cladding and substitute it for biological coatings that will interact with the
parameter to sensorize. The deposition of these layers can be made by sol-gel technology.
The sol-gel technology is being increasingly used mainly due to the high versatility to tailor their optical features.
Incorporation of suitable chemical and biochemical sensing agents have allowed determining pH, gases, and biochemical
species, among others. Nonetheless, the relatively high processing temperatures and short lifetime values mean severe
drawbacks for a successful exploitation of sol-gel based coated optical fibres. With regard to the latter, herein we present
the design, preparation and characterization of novel sol-gel coated optical fibres. Low temperature and UV curable
coating formulations were optimized to achieve a good adhesion and optical performance. The UV photopolymerizable
formulation was comprised by glycidoxypropyltrimethoxysilane (GLYMO), Tetraethylorthosilicate (TEOS) and an
initiator. While the thermoset coating was prepared by using 3-aminopropyltrimethoxysilane, GLYMO, and TEOS as
main reagents. Both curable sol-gel coated fibres were analysed by FTIR, SEM and optical characterization.
Furthermore, in the present work a new technique for silica cladding removal has been developed by ultra-short pulses
laser processing, getting good dimensional accuracy and surface integrity.