Conjugated Polymer−Titania Nanoparticle Hybrid Films: Random Lasing Action and Ultrasensitive Detection of Explosive Vapors

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• 作者：Changmin Deng ; Qingguo He ; Chao He ; Liqi Shi ; Jiangong Cheng ; Tong Lin
• 刊名：Journal of Physical Chemistry B
• 出版年：2010
• 出版时间：April 8, 2010
• 年：2010
• 卷：114
• 期：13
• 页码：4725-4730
• 全文大小：338K
• 年卷期：v.114,no.13(April 8, 2010)
• ISSN：1520-5207

文摘

We have first demonstrated that a random laser action generated by a hybrid film composed of a semiconducting organic polymer (SOP) and TiO₂ 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 TiO₂ 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 × 10¹²/cm³) of TiO₂ 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.