Trace Explosive Detection Based on Photonic Crystal Amplified Fluorescence

Abstract

With increasing demand for public security and environmental protection, it is highly desirable to develop strategies to identify trace explosives (e. g., 2,4,6-trinitrotoluene (TNT)). Herein, we report novel photonic crystal (PC)based sensor chips for trace TNT detection by using amplification effect of PCs on fluorescence (FL) signals. The sensor chips are constructed by integrating silica nanoparticles (NPs) modified with (3-aminopropyl)triethoxysilane (APTES) and fluorescein isothiocyanate isomer (FITC) and PC substrates. The amino groups on FITC-APTES-silica NPs can specifically bind with TNT molecules to form Meisenheimer complexes and strongly quench the FL signal of neighboring fluorophores FITC through Förster resonance energy transfer. PCs with matched PBG can amplify the FL signal of FITC-APTES-silica NPs about 24.4-fold and significantly improve sensitivity and resolution of trace TNT detection with the limit of detection of 0.23 nM. The PC-based sensor chips are stable, sensitive, and reliable TNT sensing platforms, showing great potential in homeland safety and environmental protection.

New Fluorescent Reporters Capable of Ultra-Sensitively Detecting Trinitrotoluene on Surfaces: A Proof-of-Concept for Finding Hidden Nitroaromatics in the Workroom

“…For the simplicity of the method, this LOD competes in accuracy with alternative, much more complicate methodologies. [69] Similarly, titrations of AR85 solutions, 2.5 µM in toluene, with increasing amounts of TNB at λ exc = 330 nm, λ em = 365 nm and 400 nm, at 25 • C gave the titration curves and titration profile for TNB showed in Fig. 5.…”

Scalable production of structurally colored composite films by shearing supramolecular composites of polymers and colloids

“…12 and Supplementary Figs. [26][27][28]. To further show the advantages of shearing supramolecular composites over previously reported shearing strategies, we compared the processing performance of shearinduced colloidal arrangements in implementing colloids with coreinterlayer-shell structures and supramolecular composites from the perspectives of the processing temperature and T g of the matrix polymer.…”

“…Among the various functional nanomaterials, structurally colored composite films (SCCFs) composed of orderly arranged colloids embedded in the polymeric matrix have gained immense interest in scientific and industrial communities 11,12 . These SCCFs process both the structural color endowed by the orderly arrangement of colloids and the flexibility and functionality of polymers 1,8,11,13 , making them promising for applications in various fields, including displays [14][15][16] , anticounterfeiting 17,18 , colorful coatings 19,20 , visual sensing [21][22][23] , solar cells 24 , and optical fibers 25 .Generally, solvent evaporation-induced colloidal assembly is commonly used to produce SCCFs from colloids [26][27][28] . This assembly process is conducted in a liquid dispersion medium, where the ordered arrangement of colloids is driven by the dynamic balance between electrostatic repulsion, solvation forces, van der Waals forces, and capillary forces generated by the volatilization of the medium 19,[29][30][31] .…”

“…Generally, solvent evaporation-induced colloidal assembly is commonly used to produce SCCFs from colloids [26][27][28] . This assembly process is conducted in a liquid dispersion medium, where the ordered arrangement of colloids is driven by the dynamic balance between electrostatic repulsion, solvation forces, van der Waals forces, and capillary forces generated by the volatilization of the medium 19,[29][30][31] .…”

Shape memory photonic materials: fabrication and emerging applications

“…15–18 PCs with specific optical performances can be constructed by customizing structures on the nanoscale. 4,19,20 In particular, inspired by the dynamically responsive coloration strategies that natural organisms ( i.e. , chameleon and brown alga) make to perceive and adapt to the variations in their surroundings, PCs with variable structures and precisely tunable structural color have attracted increasing attention.…”