表面修飾不同形貌奈米銀應用於表面電漿共振有機氣體感測器之研究

Abstract

本實驗目的在觀察不同形貌之奈米銀粒子在感測揮發性有機氣體 VOC 時，對光學造成的影響。實驗上合成球型 ( Sphere )、三角板( Triangular silver nanoplates, TSNP ) 、立方體 ( Cubic ) 三種形狀之奈米銀，分別自組裝在玻璃感測器上，製作成微小化裝置，主要的吸收波峰位置從球型約 390 nm 位移至三角板 600 nm，立方體主要的波峰在 550 nm，並利用實驗室發展的氣體生成系統，比較三者間在光學上對校正曲線斜率的響應，根據電場分布的特性，證實了具有尖端結構的粒子擁有最好的感測能力。 另外，將奈米銀自組裝感測器各別修飾上聚二甲基矽氧烷以及石墨烯 ( Graphene oxide, GO ) 薄膜，這時候奈米銀在相同的空間裡可感測到更多的氣體分子，因此能增強奈米銀局部表面電漿共振，提升感測器的靈敏度。然而，相較於聚合物，發現石墨烯更能有效提升奈米銀的靈敏度，這項研究為以奈米結構為基底的光學感測器提升了一個層次，butanol 感測可上升 3.28 倍，m-xylene 感測可上升 2.78 倍。

The purpose of this study was to observe the optical effects of silver nanoparticles in different morphologies when sensing volatile organic gas VOCs. Experimentally, three types of silver nanoparticles which are Sphere, Triangular silver nanoplates ( TSNP ) and cubic, were self-assembled on the glass, respectively, and they were made into microstructures gas sensor. TSNP LSPR peak changed from 390nm that in sphere to 600nm. And cubic is 550nm. Combined with the gas generation system developed by the laboratory, the response of the three curves to the slope of the calibration curves were compared. According to the characteristics of the electric field distribution, it was confirmed that the particles with the tip structure have the highest sensing capability. In addition, as the sensor with silver nanoparticles self-assembly was modified with poly ( dimethylsiloxane ) and graphene oxide ( GO ) film. Therefore, silver nanoparticles can sense more gas molecules, so it can enhance the local surface plasma resonance ( LSPR ), and improve the sensitivity of the sensor. However, compared with polymers, we found that graphene oxide is better in enhancing the sensitivity of nano silver. This study has raised the level of optical sensors based on nanostructures. The sensing of butanol can be increased 3.28 times, m-xylene increased 2.78 times.