title: Inverted opal fluorescent film chemosensor for the detection of explosive nitroaromatic vapors through fluorescence resonance energy transfer.
abstract: This paper reports an inverted opal fluorescence chemosensor for the ultrasensitive detection of explosive nitroaromatic vapors through resonance-energy-transfer-amplified fluorescence quenching. The inverted opal silica film with amino ligands was first fabricated by the acid-base interaction between 3-aminopropyltriethoxysilane and surface sulfonic groups on polystyrene microsphere templates. The fluorescent dye was then chemically anchored onto the interconnected porous surface to form a hybrid monolayer of amino ligands and dye molecules. The amino ligands can efficiently capture vapor molecules of nitroaromatics such as 2,4,6-trinitrotoluene (TNT) through the charge-transfer complexing interaction between electron-rich amino ligands and electron-deficient aromatic rings. Meanwhile, the resultant TNT-amine complexes can strongly suppress the fluorescence emission of the chosen dye by the fluorescent resonance energy transfer (FRET) from the dye donor to the irradiative TNT-amino acceptor through intermolecular polar-polar resonance at spatial proximity. The quenching response of the highly ordered porous films with TNT is greatly amplified by at least 10-fold that of the amorphous silica films, due to the interconnected porous structure and large surface-to-volume ratio. The inverted opal film with a stable fluorescence brightness and strong analyte affinity has lead to an ultrasensitive detection of several ppb of TNT vapor in air.
authors.affiliation: Institute of Intelligent Machines, Chinese Academy of Sciences, P. O. Box 1130, 230031, P.R. China.
authors.forename: Qunling
authors.initials: Q
authors.lastname: Fang
authors.forename: Junlong
authors.initials: J
authors.lastname: Geng
authors.forename: Bianhua
authors.initials: B
authors.lastname: Liu
authors.forename: Daming
authors.initials: D
authors.lastname: Gao
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Zhenyang
authors.initials: Z
authors.lastname: Wang
authors.forename: Guijian
authors.initials: G
authors.lastname: Guan
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Zhang