Department of Chemistry, Seoul National University, Seoul 151-747, South Korea.
Department of Chemistry, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, South Korea.
Nano Lett. 2021 Mar 10;21(5):2132-2140. doi: 10.1021/acs.nanolett.0c04883. Epub 2021 Feb 17.
There has been enormous interest in understanding and utilizing plasmon-enhanced fluorescence (PEF) with metal nanostructures, but maximizing the enhancement in a reproducible, quantitative manner while reliably controlling the distance between dyes and metal particle surface for practical applications is highly challenging. Here, we designed and synthesized fluorescence-amplified nanocuboids (FANCs) with highly enhanced and controlled PEF signals, and fluorescent silica shell-coated FANCs (FS-FANCs) were then formed to fixate the dye position and increase particle stability and fluorescence signal intensity for biosensing applications. By uniformly modifying fluorescently labeled DNA on Au nanorods and forming ultraflat Ag shells on them, we were able to reliably control the distance between fluorophores and Ag surface and obtained an ∼186 fluorescence enhancement factor with these FANCs. Importantly, FS-FANCs were utilized as fluorescent nanoparticle tags for microarray-based miRNA detection, and we achieved >10-fold higher sensitivity than commercially available chemical fluorophores with 100 aM to 1 pM dynamic range.
人们对理解和利用金属纳米结构的等离子体增强荧光（PEF）产生了浓厚的兴趣，但要以可重复和定量的方式最大限度地提高增强效果，同时可靠地控制染料和金属粒子表面之间的距离，以满足实际应用的需求，这极具挑战性。在这里，我们设计并合成了具有高度增强和可控 PEF 信号的荧光放大纳米立方（FANC），然后形成荧光二氧化硅壳层包覆的 FANC（FS-FANC），以固定染料位置并提高粒子稳定性和荧光信号强度，用于生物传感应用。通过在 Au 纳米棒上均匀修饰荧光标记的 DNA，并在其上形成超平整的 Ag 壳，我们能够可靠地控制荧光团与 Ag 表面之间的距离，并获得了这些 FANC 的约 186 倍的荧光增强因子。重要的是，我们将 FS-FANC 用作基于微阵列的 miRNA 检测的荧光纳米颗粒标记物，并实现了比商业上可用的化学荧光染料高 10 倍以上的灵敏度，动态范围为 100 aM 至 1 pM。
