Fluorescent polymer-porous silicon microcavity devices for explosive detection

Conjugated polymers entrapped in porous silicon microcavity have been studied as optical sensors for low volatility explosives such as trinitrotoluene. The fluorescence spectra of entrapped polymers were modulated by the microcavity via a spectral “hole” that matches the resonance peak of the microcavity reflectance. Exposure of the porous silicon microcavity containing entrapped polymer to explosives vapor results in a red shift of the resonance peak and the spectral hole, accompanied by the quenching of the fluorescence. This multiplexed response provides multiple monitoring parameters, enabling the development of an optical sensor array for the detection of target explosive vapor.