奈米銀島狀薄膜的製備並應用在生物感測器上的研究

Abstract

奈米金屬材料的局部表面電漿共振(Localized Surface Plasmon Resonance,LSPR)對螢光物質有明顯的螢光增強，由於螢光分子與具有LSPR的表面有交互作用(Interaction)，此現象稱為金屬螢光增強(Metal-Enhancement Fluorescence,MEF)。 本研究以無電鍍的方法製備銀島狀薄膜，此方法具有高度的便利性且快速，對環境無害且友善。另外此方法藉由改變整體銀的覆蓋率與改變氨水的量來改善表面形貌，多數條件的島狀銀的粒徑/間隙比大於2以上。銀的散射效率對於放射波長位在進紅外光的IR800有顯著的螢光增強，由於銀的LSPE peak與IR800放射波長有重疊，另外較窄的間隙使局部的電磁場更為增強，由於兩奈米粒子間的耦合(Coupling)現象。 本材料與對照組比較有明顯的螢光增強，提升了系統的偵測極限，當銀的濃度為500uM時，對IR800的螢光增強達到最大值，偵測到的最大值接近500倍，平均螢光增強接近350倍。

Nano metal materials has significantly fluorescence enhancement due to its localized surface plasmon resonance (LSPR) characteristic. The fluorophore interaction with plasmonic substrates were investigated by many researcher, this phenomenon called metal-enhancement fluorescen-ce (MEF). In this study, preparation of silver nano-island films (SIF) by electroless plating, this is a convenience and fast method that is environ-ment friendly and non-toxic. In addition, a strong MEF activity attributed to surface morphology so that this study change concentration of the silver and mole number of the ammonia for improvement surface morphology. In our experiment, most of the conditions of SIFs has outstanding size/gap ratio, most of them large than 2. Silver is a commonly used material because its SPR is typically in the visible region. Plasmonic peaks of SIF overlaps with the fluorescence emission wavelength of IR800.This material can effective increase fluorescence intensity and improve system detection limit. The enhancement factor reach close to 500 fold and average enhancement factor close to 350 fold.