This paper scrutinises the development of low-cost hypersensitive fluorescent probes manipulated chemically with Schiff base complexes and their prospective applicability for the detection of nitro explosives in light of the rapidly expanding demand for anti-trafficking measures. In this study, a new Zn(II) metal complex has been synthesized in one pot using the Schiff base ligand L= 2-methoxy-5-methyl-N-(2-pyridin-2-ylmethylene) aniline. The complex was also thoroughly characterised using various spectroscopic tools and subjected to single crystal XRD analysis. In the asymmetric unit, square pyramidal zinc (II) centre exist in the inner N2O compartment of the ligand L. The intermolecular Cg···Cg interactions exist between two different asymmetric residual units lead to supramolecular assembly along b axis. By turning off the fluorescence response, the complex serves as a sensor for the detection of nitro aromatics in CH3CN solution. A significant quenching efficiency has been reported with a quenching constant (KSV) 1.8 × 104 M-1 for 4-nitrobenzoic acid during investigation of sensing phenomenon in solution phase. In addition, determining the binding stoichiometry of the chemosensor with NO2 and the binding constant, the mechanism of fluorescence quenching has also been postulated. The detection limit of NO2 is 7.6×10 -7 M, with the binding constant k = 1.1021× 108 M-1. Additionally, the DFT calculation makes it easier to comprehend the appropriate binding process in light of the findings of experiments. We also designed a paper sensor strip for the visual detection of Nitro Explosive Residues in light of the sensor\'s potential used in forensic investigations.

Graphenic substrates (GS), such as reduced graphene oxide (rGO) and graphene oxide (GO), are 2D materials known for their unique physicochemical properties such as their ability to enhance vibrational spectroscopic signals and quench the fluorescence of adsorbed molecules. These properties provide an opportunity to develop nanostructured GS-based systems for detecting and identifying different analytes with high sensitivity and reliability through molecular spectroscopic techniques. This work evaluated the capacities of different GS to interact with a highly fluorescent compound, thereby changing its optical emission response (fluorescence quenching) and amplifying its vibrational signal, which is the base of graphene-enhanced Raman scattering (GERS). To test these properties, we used a derivative of highly fluorescent BODIPY (BP) compounds, which cover a wide range of applications from solar energy conversion to photodynamic cancer therapy. GS prepared by using the Langmuir-Blodgett (LB) technique allowed us to quench the fluorescence emission of BP and improve its Raman spectroscopy detection limit due to the GERS effect. These results were interpreted in light of the π-π interactions taking place between the Csp2 domains of GS and the aromatic core of the BP fluorophore.