Rapid detection of TNP based on a commercial fluorescent probe

A hydroxyl-rich covalent organic framework for the precisely selective fluorescence sensing of explosives with high sensitivity

Covalent organic Frameworks (COFs) have become a new platform for functional research and material design. A novel covalent organic skeleton (DHB-TFP COF) was synthesized from 2-hydroxybenzene-1,3,5-tricarbaldehyde and 3,3'-dihydroxybenzidine using Schiff base reaction. DHB-TFP COF is a highly stable porous crystalline material and exhibits exceptional thermal and chemical resistance. DHB-TFP COF exhibited a selective and sensitive "turn-off" fluorescence response to 4-NP in ethanol, and TNP not only significantly quenched the fluorescence of DHB-TFP COF but also caused the obvious red-shift. The fluorescence intensity of DHB-TFP COF exhibited a linear correlation with the concentration of 4-NP with a detection limit of 0.40 μM. Furthermore, the maximum fluorescence peak observed for DHB-TFP COF demonstrated a linear relationship with TNP concentration with a detection limit of 11.15 μM. DHB-TFP COF exhibited satisfactory recovery in the detection of 4-NP and TNP in actual water sample indicating its practical application potential. The O atoms of rich hydroxyl and N atoms of C = N present on the surface of DHB-TFP COF scaffold can establish strong hydrogen bonds with 4-NP and TNP, facilitating their mutual interaction. The spectra studies indicated that the fluorescence quenching mechanism can be attributed to the absorption competitive quenching (ACQ) and fluorescence resonance energy transfer (FRET) mechanism. This study not only proposed the approach for synthesizing novel structured organic frameworks, but also developed a highly selective and sensitive fluorescence chemical sensor for identifying and detecting 4-NP and TNP.

Interpol review of detection and characterization of explosives and explosives residues 2016-2019

This review paper covers the forensic-relevant literature for the analysis and detection of explosives and explosives residues from 2016-2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/Resources/Documents#Publications.