This paper reports a resonance energy transfer-amplifying fluorescence quenching at the surface of silica nanoparticles for the ultrasensitive detection of 2,4,6-trinitrotoluene (TNT) in solution and vapor environments. Fluorescence dye and organic amine were covalently modified onto the surface of silica nanoparticles to form a hybrid monolayer of dye fluorophores and amine ligands. The fluorescent silica particles can specifically bind TNT species by the charge-transfer complexing interaction between electron-rich amine ligands and electron-deficient aromatic rings. The resultant TNT−amine complexes bound at the silica surface can strongly suppress the fluorescence emission of the chosen dye by the fluorescence resonance energy transfer (FRET) from dye donor to the irradiative TNT−amine acceptor through intermolecular polar−polar interactions at spatial proximity. The quenching efficiency of the hybrid nanoparticles with TNT is greatly amplified by at least 10-fold that of the corresponding pure dye. The nanoparticle-assembled arrays on silicon wafer can sensitively detect down to ∼1 nM TNT with the use of only 10 μL of solution (∼2 pg TNT) and several ppb of TNT vapor in air. The simple FRET-based nanoparticle sensors reported here exhibit a high and stable fluorescence brightness, strong analyte affinity, and good assembly flexibility and can thus find many applications in the detection of ultratrace analytes.
本文报道了
二氧化硅纳米颗粒表面的共振能量转移放大荧光猝灭,用于溶液和蒸汽环境中
2,4,6-三硝基甲苯 (TNT) 的超灵敏检测。荧光
染料和有机胺被共价修饰到
二氧化硅纳米颗粒的表面,形成
染料荧光团和胺
配体的混合单层。荧光
二氧化硅颗粒可以通过富电子胺
配体和缺电子芳环之间的电荷转移络合相互作用特异性结合TNT物质。由此产生的 TNT-胺复合物结合在
二氧化硅表面,可以通过空间邻近的分子间极性相互作用,通过从
染料供体到辐射性 TNT-胺受体的荧光共振能量转移(FRET),强烈抑制所选
染料的荧光发射。与 TNT 混合的纳米颗粒的猝灭效率比相应的纯
染料大大提高了至少 10 倍。
硅晶片上的纳米粒子组装阵列只需使用 10 μL 溶液(∼2 pg TNT)和空气中数 ppb 的 TNT 蒸气即可灵敏地检测低至 ∼1 nM TNT。本文报道的简单的基于 FRET 的纳米颗粒传感器表现出高且稳定的荧光亮度、强分析物亲和力和良好的组装灵活性,因此可以在超痕量分析物的检测中找到许多应用。