利用奈米球微影術製作奈米銀顆粒陣列於表面增強拉曼散射之生物感測應用

Abstract

本文為使用奈米球微影術（NSL）製作表面增強拉曼散射（SERS）基板並探討其靈敏度。我們使用直徑為430nm至1500nm的聚苯乙烯奈米球製作了AgFON結構與奈米銀顆粒陣列，在AgFON結構中，隨著聚苯乙烯奈米球的尺寸變化，表面增強拉曼散射增強因子會有最佳化的趨勢，而在奈米銀顆粒陣列中，隨著控制銀顆粒的尺寸與高度變化將可調整表面增強拉曼散射增強因子，另外，將奈米銀顆粒陣列基板應用於生物量測中，可以量測河魨者最低濃度為0.9 ng/mL，其靈敏度已經和高效液相層析儀（HPLC）相同，顯示了表面增強拉曼散射感測系統的高靈敏度與即時量量測等多項優點。In this paper, two kinds of substrates for surface-enhanced Raman scattering (SERS) are fabricated with different sizes of polystyrene nanospheres by using nanosphere lithography (NSL). The dependence of SERS enhancement on nanoparticle size has been studied. In the AgFON structure, optimum SERS signal is obtained with a nanosphere size of 1000 nm at an excitation wavelength of 532 nm. In addition, the SERS intensity of R6G molecules adsorbed on Ag nanoparticle array is demonstrated to be controllable by tuning the size and height of the nanoparticles. We also demonstrate biological application of SERS by using Ag nanoparticle arrays substrate. The optical properties of tetrodotoxin (TTX), a scarce toxin with anesthetic properties, were studied using nanoparticle arrays-assisted SERS. In the SERS experiment, we were able to measure the Raman spectrum with a TTX concentration as less as 0.9ng/mL. This sensitivity is comparable to that from high performance liquid chromatography (HPLC).