AbstractAn in-plane flexible sensor platform for BTXs detection was developed using low-cost patterning techniques and foil-based optical components. The platform was produced by a combination of laser patterning, inkjet printing and capillary filling. Key optical components such as lightguides, optical cladding layers and metallic interconnections were realized on low cost substrates such as paper and PET. The sensing mechanism is based on the change in fluorescence spectra of a reporter dye, supported over a porous matrix. Detection limits down to 1ppm for benzene, toluene and xylene have been measured. Response times down to a few seconds were observed for different gas concentrations.