Surface-Enhanced Raman Scattering Spectroscopy of Explosive 2,4-Dinitroanisole using Modified Silver Nanoparticles

Abstract

2,4-Dinitroanisole (DNAN) is being used as a replacement for 2,4,6-trinitrotoluene (TNT) as a less-sensitive melt-cast medium explosive than TNT. In this paper, we studied the surface-enhanced Raman spectroscopy (SERS) analysis of DNAN using Ag nanoparticles (AgNPs) modified by L-cysteine methyl ester hydrochloride. Due to the formation of a Meisenheimer complex between DNAN and the modifier, the modified AgNPs can detect 20 μg/L (0.2 ng) and 0.1 mg/L (1 ng) DNAN in deionized water and aged tap water, respectively. Three other chemicals (L-cysteine, N-acetyl-L-cysteine, and L-cysteine ethyl ester hydrochloride) were used as AgNPs modifiers to study the mechanism of the SERS of DNAN. It was confirmed that the amino group of L-cysteine methyl ester hydrochloride was the active group and that the methyl ester group significantly contributed to the high SERS sensitivity of DNAN. In order to further test the mechanism of Meisenheimer complex formation, the effect of anions and cations present in natural water on the SERS of DNAN was studied. It was found that CO(3)(2-), Cl(-), and K(+) at 100 mg/L did not negatively affect the SERS of 10 mg/L DNAN, while SO(4)(2-), Na(+), Mg(2+), and Ca(2+) at 100 mg/L significantly quenched the SERS of 10 mg/L DNAN. The negative effect of the bivalent cations could be offset by SO(4)(2-).

Detection and identification of explosives by surface enhanced Raman scattering

“…Besides TNT and DNT, other military explosives and precursors have started to be investigated by SERS including RDX [26, 28-32, 44, 52, 55, 60], HMX [26], NG [27,28], tetryl [28], PETN [29][30][31], EGDN [29,30], KNO3 [31], DNAN [61], NTO [62], and HNIW [24].…”

Smart supramolecular sensing with cucurbit[n]urils: probing hydrogen bonding with SERS

“…Surface-Enhanced Raman Scattering (SERS) has attracted wide-spread interest on account of its potential for sensing down to the single molecule level. [1][2][3][4][5][6][7][8] This has led to a wealth of research on detecting trace amounts of pollutants, 9 poisons 10 and explosives, 11,12 achieved by plasmonic constructs such as core-shell nanoparticles, 13 nanostars, [14][15][16][17][18] nanoparticle aggregates, 19,20 nanowire junctions [21][22][23][24] and plasmonic tips [25][26][27] (Tip-Enhanced Raman Scattering, TERS). Recently, SERS has also been used to study reactions 28 and conformational changes in molecules.…”

Silver nano-entities through ultrafast double ablation in aqueous media for surface enhanced Raman scattering and photonics applications

“…In the present work, we extensively investigated the (a) nonlinear optical (NLO) properties of Ag colloids achieved through multiple/double ablation in double distilled water; (b) the effect of multiple/double ablation in defining the size, shape of the fabricated nano-entities on Ag surface and their SERS activity using R6G; (c) the influence of laser fluence on structures in the case of double ablation; and (d) Raman signal enhancements of 1,3,5-Trinitroperhydro-1,3,5-triazine [Research Department eXplosive (RDX)] molecules adsorbed on the nanostructured Ag substrates. The last part of the work is significant since identification of explosives [46][47][48][49] at very low concentrations in different environments is a predicament of critical interest for security and forensic diagnostics. Silver has been chosen because of (i) cost-effectiveness compared to gold, (ii) tendency towards oxidation is less compared to copper, and (iii) capacity to support strong Plasmon resonances.…”