Sensing and Discrimination of Explosives at Variable Concentrations with a Large-Pore MOF as Part of a Luminescent Array

Abstract

Metal-organic frameworks (MOFs) have shown great promise for sensing of dangerous chemicals, including environmental toxins, nerve agents and explosives. However, challenges remain, such as the sensing of larger analytes and the discrimination between similar analytes at different concentrations. Herein we present the synthesis and development of a new, large-pore MOF for explosives sensing, and demonstrate its excellent sensitivity against a range of relevant explosive compounds including trinitrotoluene (TNT) and pentaerythritol tetranitrate (PETN). We have developed an improved, thorough methodology to eliminate common sources of error in our sensing protocol. We then combine this new MOF with two others as part of a three-MOF array for fluorescent sensing and discrimination of five explosives. This sensor works at part-permillion concentrations and importantly, can discriminate explosives with high accuracy without reference to their concentration.

Recent Developments in the Field of Explosive Trace Detection

“…Schulte-Ladbeck et al overcame this by using catalase to remove trace hydrogen peroxide in samples prior to testing, followed by decomposition of explosive material through UV photolysis and detection of the resultant hydrogen peroxide using 2,2'-azino-bis(3ethylbenzothiazoline)-6-sulfonate (ABTS) and p-hydroxyphenylacetic acid (pHPAA) in the presence of horseradish peroxidase. 242 247 Various signal transduction approaches have been adopted to enhance the sensitivity of MOF materials. Recently, a Cu-MOF was linked to an optical fibre Fabry-Pérot interferometer (FPI) to achieve real-time detection of nitrobenzene.…”

A luminescent Zn-MOF for the detection of explosives and development of fingerprints

“…But simultaneously, the use of explosive materials for destructive impetus cannot be ignored, which demands the development of a high-quality latent fingerprint for the assessment at crime scenes. Amongst the explosive materials, organic nitro-aromatic, nitro-aliphatic and nitramine are preferred 1,2 for various civilian applications. 3 For example, RDX and PETN are frequently used in plastic formulations and Semtex.…”

An MOF‐Based Luminescent Sensor Array for Pattern Recognition and Quantification of Metal Ions

“…[ 32–50 ] In principle, incorporation of several luminescent centers with unique emission responses for different analytes within a single MOF should be a very promising approach to realize luminescent sensor arrays, however, this has hardly been realized. [ 51–55 ] Herein we report a single‐phased array sensor based on MOF material for metal ions recognition. As a proof‐of‐concept system, we simultaneously incorporated Eu 3+ and organic dye, 3,3′‐diethyloxacarbocyanine iodide (DOC), into a luminescent MOF, MOF‐253, to obtain a multiple‐emissive material, MOF‐253⊃Eu 3+ +DOC ( Scheme ).…”