title: Inkjet-printed silver nanoparticle paper detects airborne species from crystalline explosives and their ultratrace residues in open environment.
abstract: An electronic nose can detect highly volatile chemicals in foods, drugs, and environments, but it is still very much a challenge to detect the odors from crystalline compounds (e.g., solid explosives) with a low vapor pressure using the present chemosensing techniques in such way as a dog's olfactory system can do. Here, we inkjet printed silver nanoparticles (AgNPs) on cellulose paper and established a Raman spectroscopic approach to detect the odors of explosive trinitrotoluene (TNT) crystals and residues in the open environment. The layer-by-layer printed AgNP paper was modified with p-aminobenzenethiol (PABT) for efficiently collecting airborne TNT via a charge-transfer reaction and for greatly enhancing the Raman scattering of PABT by multiple spectral resonances. Thus, a Raman switch concept by the Raman readout of PABT for the detection of TNT was proposed. The AgNPs paper at different sites exhibited a highly uniform sensitivity to TNT due to the layer-by-layer printing, and the sensitive limit could reach 1.6 × 10(-17) g/cm(2) TNT. Experimentally, upon applying a beam of near-infrared low-energy laser to slightly heat (but not destruct) TNT crystals, the resulting airborne TNT in the open environment was probed at the height of 5 cm, in which the concentration of airborne species was lower than 10 ppt by a theoretical analysis. Similarly, the odors from 1.4 ppm TNT in soil and 7.2, 2.9, and 5.7 ng/cm(2) TNT on clothing, leather, and envelope, respectively, were also quickly sensed for 2 s without destoying these inspected objects.
authors.affiliation: Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.forename: Bianhua
authors.initials: B
authors.lastname: Liu
authors.forename: Haihe
authors.initials: H
authors.lastname: Jiang
authors.forename: Renyong
authors.initials: R
authors.lastname: Liu
authors.forename: Jingwei
authors.initials: J
authors.lastname: Yang
authors.forename: Guangmei
authors.initials: G
authors.lastname: Han
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Mei
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Zhang