Kim Jun, Abbas Naseem, Lee Seongmin, Yeom Jeongwoo, Asgar Md Ali, Badshah Mohsin Ali, Lu Xun, Kim Young Kyu, Kim Seok-Min
Department of Mechanical Engineering, Chung-Ang University, Seoul 06974, Korea.
Department of Mechanical System Engineering, Chung-Ang University, Seoul 06974, Korea.
Polymers (Basel). 2020 Dec 25;13(1):48. doi: 10.3390/polym13010048.
A simple and cost-effective method is proposed herein for a plasmonic nanoantenna array (PNAA) for the fabrication of metal-enhanced fluorescence (MEF) substrates in which fluorophores interact with the enhanced electromagnetic field generated by a localized surface plasmon to provide a higher fluorescence signal. The PNAA is fabricated by the deposition of a silver (Ag) layer on an ultraviolet (UV) nanoimprinted nanodot array with a pitch of 400 nm, diameter of 200 nm, and height of 100 nm. During deposition, raised Ag nanodisks and a lower Ag layer are, respectively, formed on the top and bottom of the imprinted nanodot array, and the gap between these Ag layers acts as a plasmonic nanoantenna. Since the thickness of the gap within the PNAA is influenced by the thickness of Ag deposition, the effects of the latter upon the geometrical properties of the fabricated PNAA are examined, and the electromagnetic field intensity distributions of PNAAs with various Ag thicknesses are simulated. Finally, the fluorescence enhancement factor (FEF) of the fabricated PNAA MEF substrate is measured using spotted Cy5-conjugated streptavidin to indicate a maximum enhancement factor of ~22× for the PNAA with an Ag layer thickness of 75 nm. The experimental results are shown to match the simulated results.
本文提出了一种简单且经济高效的方法来制备用于制造金属增强荧光（MEF）基板的等离子体纳米天线阵列（PNAA），其中荧光团与由局域表面等离子体产生的增强电磁场相互作用，以提供更高的荧光信号。PNAA是通过在具有400nm间距、200nm直径和100nm高度的紫外（UV）纳米压印纳米点阵列上沉积银（Ag）层来制造的。在沉积过程中，凸起的Ag纳米盘和较低的Ag层分别形成在压印纳米点阵列的顶部和底部，并且这些Ag层之间的间隙充当等离子体纳米天线。由于PNAA内间隙的厚度受Ag沉积厚度的影响，因此研究了后者对所制造的PNAA几何特性的影响，并模拟了具有不同Ag厚度的PNAA的电磁场强度分布。最后，使用斑点化的Cy5缀合链霉亲和素来测量所制造的PNAA MEF基板的荧光增强因子（FEF），结果表明，对于Ag层厚度为75nm的PNAA，最大增强因子约为22倍。实验结果与模拟结果相匹配。
