SPR Enhanced molecular imprinted sol–gel film: A promising tool for gas-phase TNT detection

•A molecular imprinted sol–gel film was used as simple and low cost sensing layer.•A grating-based SPR architecture and molecular imprinted sol–gel matrix were combined as novel sensing platform.•TNT traces were detected down to 4.9 ppb using a novel SPR sensing approach sensitive to TNT concentration <1 ppb.

An innovative surface plasmon resonance (SPR) approach for the detection of 2,4,6-trinitrotoluene (TNT) gas traces, obtained using an engineered molecular imprinted sol–gel film as recognition layer onto a plasmonic gold grating, is here proposed. The SPR substrate combined with the sol–gel matrix is able to trap gas phase TNT molecules from a TNT-saturated environment (4.9 ppb). Taking advantage of the azimuthally-controlled grating-coupled SPR, this sensing platform demonstrates the potentiality to detect TNT traces <1 ppb with a sensitivity of 0.47°/ppb.

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