Shanghai Institute of Microsystem and Information Technology and Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200050, China.
J Phys Chem B. 2010 Apr 8;114(13):4725-30. doi: 10.1021/jp9117198.
We have first demonstrated that a random laser action generated by a hybrid film composed of a semiconducting organic polymer (SOP) and TiO(2) nanoparticles can be used to detect 2,4,6-trinitrotoluene (TNT) vapors. The hybrid film was fabricated by spin-casting SOP solution dispersed with nanosized TiO(2) particles on quartz glass. The SOP in the hybrid film functioned as both the gain medium and the sensory transducer. A random lasing action was observed with a certain pump power when the size (diameter of 50 nm) and concentration (8.9 x 10(12)/cm(3)) of TiO(2) nanoparticles were optimized. Measurements of fluorescence quenching behavior of the hybrid film in TNT vapor atmosphere (10 ppb) showed that attenuated lasing in optically pumped hybrid film displayed a sensitivity to vapors of explosives more than 20 times higher than was observed from spontaneous emission. This phenomenon has been explained with the four-level laser model. Since the sensory transducer used in the hybrid polymer/nanoparticles system could be replaced by other functional materials, the concept developed could be extended to more general domains of chemical or environment detection.
我们首次证明，由半导体有机聚合物（SOP）和 TiO2纳米粒子组成的混合薄膜产生的随机激光作用可用于检测 2,4,6-三硝基甲苯（TNT）蒸气。该混合薄膜是通过在石英玻璃上旋涂 SOP 溶液分散纳米尺寸的 TiO2粒子来制备的。混合薄膜中的 SOP 既充当增益介质又充当传感换能器。当 TiO2纳米粒子的尺寸（50nm 直径）和浓度（8.9 x 1012/cm3）优化时，在一定的泵浦功率下观察到随机激光作用。在 TNT 蒸气气氛（10ppb）中测量混合薄膜的荧光猝灭行为表明，光泵浦混合薄膜中的衰减激光对爆炸物蒸气的灵敏度比自发发射观察到的灵敏度高 20 多倍。这一现象已用四能级激光模型进行了解释。由于混合聚合物/纳米粒子系统中使用的传感换能器可以被其他功能材料所取代，因此所开发的概念可以扩展到更广泛的化学或环境检测领域。
