A Complementary Silicon Quantum Dot-Enzyme Platform for Selective Detection of Nitroaromatics Compounds

To address the issue of poor selectivity in nanotechnology-driven, portable nitroaromatics sensors, we have coupled a ratiometric photoluminescence sensor based on silicon quantum dots and fluorescent proteins with a colorimetric enzyme-based sensor. Together, the sensors allow differentiation of nitroaromatic compounds – specifically, distinguishing acetylcholinergic nerve agents from the explosive compounds explored herein. The combined system can detect 2,4,6-trinitrotoluene, 2,4-dinitrotoluene and 4-nitrophenol with micromolar detection limits and affords subsequent differentiation from the nitro-containing nerve agent paraoxon. This demonstrates the advantage of merging elements of materials chemistry and biochemistry to devise customized sensors which can accurately identify hazardous chemical species

From Hydrogen Silsesquioxane to Functionalized Silicon Nanocrystals

Silicon nanocrystals exhibit size-dependent optical and electronic properties that may be exploited for applications ranging from sensors to photovoltaics. In addition, they can be utilized in biological and environmental systems thanks to the nontoxicity of silicon. Synthesis of silicon nanocrystals has been accomplished using a variety of methods. However, creating near monodisperse systems of high purity has been a challenge. The high temperature processing of hydrogen silsesquioxane method of particle synthesis reproducibly provides pure, near monodisperse particles in scalable quantities. These particles can then be liberated using HF etching and functionalized using a variety of methods. This paper outlines our lab procedures for creating silicon nanocrystals, the various functionalization methods and the most commonly used characterization techniques