Liu Tang-Chun, Yu Wen-Hsiang, Tseng Chung-Kai, Thakur Diksha, Tai Chao-Yi
Department of Optics and Photonics, National Central University, No. 300, Zhongda Rd., Zhongli, Taoyuan, 320317, Taiwan.
Sci Rep. 2024 Sep 6;14(1):20851. doi: 10.1038/s41598-024-71900-7.
We refresh the design of zero-mode waveguides (ZMWs) by introducing metamaterials that makes the zeroth order resonant mode existence. Of particular importance, the resulting electromagnetic field exhibits nearly constant distribution but not a trivial solution of Maxwell's equation, showing great advantage to equalize the excitation rate of molecules throughout the waveguides. A closed form expression for the wave impedance is derived which is verified by the finite-difference time-domain simulations. Benefitted from the cavity Purcell effect which is lacking in existing ZMWs, fluorescence amplification and lifetime reduction are simultaneously enhanced. A practical design where the excitation volume reduced down to sub-zeptoliter and the fluorescence lifetime shortened to picosecond scale is illustrated. This result makes single molecule real time (SMRT) sensing of biochemical reactions at biophysically relevant concentrations (~ μM) possible, combining off-the-shelf ultrafast lasers.
我们通过引入超材料来刷新零模波导（ZMWs）的设计，从而使零阶共振模得以存在。特别重要的是，由此产生的电磁场呈现出近乎恒定的分布，而非麦克斯韦方程的平凡解，这在使整个波导中分子的激发速率均衡方面显示出巨大优势。推导了波阻抗的闭式表达式，并通过时域有限差分模拟进行了验证。受益于现有ZMWs所缺乏的腔珀塞尔效应，荧光放大和寿命缩短同时得到增强。展示了一种实际设计，其中激发体积减小到亚zeptoliter，荧光寿命缩短到皮秒尺度。这一结果使得结合现成的超快激光器，在生物物理相关浓度（~μM）下对生化反应进行单分子实时（SMRT）传感成为可能。
