title: Ag nanocluster/DNA hybrids: functional modules for the detection of nitroaromatic and RDX explosives.
abstract: Luminescent Ag nanoclusters (NCs) stabilized by nucleic acids are implemented as optical labels for the detection of the explosives picric acid, trinitrotoluene (TNT), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The sensing modules consist of two parts, a nucleic acid with the nucleic acid-stabilized Ag NCs and a nucleic acid functionalized with electron-donating units, including L-DOPA, L-tyrosine and 6-hydroxy-L-DOPA, self-assembled on a nucleic acid scaffold. The formation of donor-acceptor complexes between the nitro-substituted explosives, exhibiting electron-acceptor properties, and the electron-donating sites, associated with the sensing modules, concentrates the explosives in close proximity to the Ag NCs. This leads to the electron-transfer quenching of the luminescence of the Ag NCs by the explosive molecule. The quenching of the luminescence of the Ag NCs provides a readout signal for the sensing process. The sensitivities of the analytical platforms are controlled by the electron-donating properties of the donor substituents, and 6-hydroxy-L-DOPA was found to be the most sensitive donor. Picric acid, TNT, and RDX are analyzed with detection limits corresponding to 5.2 × 10(-12) M, 1.0 × 10(-12) M, and 3.0 × 10(-12) M, respectively, using the 6-hydroxy-L-DOPA-modified Ag NCs sensing module.
authors: Institute of Chemistry, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors: Natalie
authors: N
authors: Enkin
authors: Etery
authors: E
authors: Sharon
authors: Eyal
authors: E
authors: Golub
authors: Itamar
authors: I
authors: Willner
mesh_terms: D004247:DNA / Q000737:chemistry*; D053834:Explosive Agents / Q000032:analysis*; D010851:Picrates / Q000032:analysis*; D012834:Silver / Q000737:chemistry*; D014227:Triazines / Q000032:analysis*; D014303:Trinitrotoluene / Q000032:analysis*
chemical_list: D053834:Explosive Agents; D010851:Picrates; D014227:Triazines; D014303:Trinitrotoluene; D012834:Silver; D004247:DNA; C005858:picric acid; C009160:cyclonite