Using Transmissive Photonic Band Edge Shift to Detect Explosives: A Study with 2,4,6-Trinitrotoluene (TNT)

• DOI: 10.1021/acsphotonics.6b00880
• Publication Date: 2017-01-20T22:15:23Z
• Authors: Noorhayati Idros; Man Yi Ho; Varun S. Kamboj; Hua Xu; ZhongZe Gu; Harvey E. Beere; David A. Ritchie; Daping Chu
• Keywords: Trinitrotoluene; Diamondoid; Explosive detection

Photonic crystals (PhCs) possess outstanding optical properties that can be exploited for chemical sensing. We utilized a three-dimensional close-packed PhC structure made of functionalized silica nanoparticles. They consist alternating high and low refractive index regions have properties, such as photonic band structures, are very sensitive to the change physical structures. This study used 2,4,6-trinitrotoluene (TNT) illustrate detection method based on transmissive edge shift (TPBES) due binding TNT with amine anchored particle surfaces form Meisenheimer (amine-TNT) complexes. PhCs exceptionally small in caused by surface modification. As result, they suitable sensing specific reactions between an TNT. achieved wide range concentrations from 10–12 10–4 M. 2,4-Dinitrotoluene (DNT) toluene were control blank, respectively. Because gravitational sedimentation, TNT-functionalized particles self-assembled pure ethanol. measured UV–visible transmission spectroscopy. A model simulate system was built using particles' center-to-center distance (a) effective dielectric constant (ε) function concentrations. Two sets simulations performed: first set involved parametric sweep ε = 2.015. The second 263.1 nm. These perturbations yield TPBES response is agreement our experimental results.