title: Attogram sensing of trinitrotoluene with a self-assembled molecular gelator.
abstract: Detection of explosives is of utmost importance due to the threat to human security as a result of illegal transport and terrorist activities. Trinitrotoluene (TNT) is a widely used explosive in landmines and military operations that contaminates the environment and groundwater, posing a threat to human health. Achieving the detection of explosives at a sub-femtogram level using a molecular sensor is a challenge. Herein we demonstrate that a fluorescent organogelator exhibits superior detection capability for TNT in the gel form when compared to that in the solution state. The gel when coated on disposable paper strips detects TNT at a record attogram (ag, 10(-18) g) level (∼12 ag/cm(2)) with a detection limit of 0.23 ppq. This is a simple and low-cost method for the detection of TNT on surfaces or in aqueous solutions in a contact mode, taking advantage of the unique molecular packing of an organogelator and the associated photophysical properties.
authors.affiliation: Photosciences and Photonics Group, Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR, Trivandrum 695 019, India.
authors.forename: Kalathil K
authors.initials: KK
authors.lastname: Kartha
authors.forename: Sukumaran S
authors.initials: SS
authors.lastname: Babu
authors.forename: Sampath
authors.initials: S
authors.lastname: Srinivasan
authors.forename: Ayyappanpillai
authors.initials: A
authors.lastname: Ajayaghosh
mesh_terms: D053834:Explosive Agents / Q000032:analysis*; D005782:Gels; D057230:Limit of Detection; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D014303:Trinitrotoluene / Q000032:analysis*
chemical_list: D053834:Explosive Agents; D005782:Gels; D014303:Trinitrotoluene