Abstract: A sensor for gas phase trinitrotoluene (TNT) based on an integrated optical waveguide attenuated total reflectance spectrometry (IOW-ATR) platform was designed and tested. Sol-gel films molecularly imprinted for TNT were deposited on planar waveguides. The imprinted sol-gel layer provides for selective binding of TNT and subsequent conversion of TNT to the colored anionic form. Detection limits were found to be approximately one femtomole/second in air. Several different compositions of sol-gels were investigated to evaluate which formulation improved sensitivity. The molecularly imprinted sol-gel films were examined by atomic force microscopy (AFM) to measure thickness and morphology. AFM indicated that the solgel films were composed of approximately 40 nm particles dispersed as a monolayer on the waveguide surface. The effect of morphology on sensor response was investigated.
Template and target information: 2,4,6-trinitrotoluene, TNT