Species specific chemical sensing using molecularly imprinted coatings on optical fibre long period gratings

The combination of photonic devices with functional nanomaterials offers great promise for the development of highly sensitive and selective chemical sensors. The team at Cranfield has been exploiting optical fibre long period gratings as a sensing platform, depositing thin (of order 100nm) coatings of chemically sensitive materials onto the fibre to provide selective response to target analytes. The presentation will provide an overview of the properties of long period gratings and discuss the means for optimising the sensitivity of the device to the optical properties of the surrounding material. The performance of sensors with a variety of coatings deposited via lay-by-layer techniques will be presented, with a focus on molecularly imprinted coatings, where template-shaped cavities are formed in polymers matrices and in metal oxide matrices are shown to offer selective sensitivity to target analytes.