School of Physics, Dalian University of Technology, Dalian 116024, China.
College of Physical Science and Technology, Dalian University, Dalian 116622, China.
Biosensors (Basel). 2023 Jun 14;13(6):649. doi: 10.3390/bios13060649.
Plasmonic metal nanostructures have promising applications in biosensing due to their ability to facilitate light-matter interaction. However, the damping of noble metal leads to a wide full width at half maximum (FWHM) spectrum which restricts sensing capabilities. Herein, we present a novel non-full-metal nanostructure sensor, namely indium tin oxide (ITO)-Au nanodisk arrays consisting of periodic arrays of ITO nanodisk arrays and a continuous gold substrate. A narrow-band spectral feature under normal incidence emerges in the visible region, corresponding to the mode-coupling of surface plasmon modes, which are excited by lattice resonance at metal interfaces with magnetic resonance mode. The FWHM of our proposed nanostructure is barely 14 nm, which is one fifth of that of full-metal nanodisk arrays, and effectively improves the sensing performance. Furthermore, the thickness variation of nanodisks hardly affects the sensing performance of this ITO-based nanostructure, ensuring excellent tolerance during preparation. We fabricate the sensor ship using template transfer and vacuum deposition techniques to achieve large-area and low-cost nanostructure preparation. The sensing performance is used to detect immunoglobulin G (IgG) protein molecules, promoting the widespread application of plasmonic nanostructures in label-free biomedical studies and point-of-care diagnostics. The introduction of dielectric materials effectively reduces FWHM, but sacrifices sensitivity. Therefore, utilizing structural configurations or introducing other materials to generate mode-coupling and hybridization is an effective way to provide local field enhancement and effective regulation.
等离子体金属纳米结构由于能够促进光物质相互作用，在生物传感中有很好的应用前景。然而，贵金属的阻尼导致了较宽的半峰全宽（FWHM）谱，限制了传感能力。在此，我们提出了一种新型的非全金属纳米结构传感器，即由周期性的氧化铟锡（ITO）纳米盘阵列和连续的金衬底组成的氧化铟锡-金纳米盘阵列。在可见光区出现了窄带光谱特征，对应于表面等离子体模式的模式耦合，这些模式是由金属界面的晶格共振与磁共振模式激发的。我们提出的纳米结构的 FWHM 只有 14nm，是全金属纳米盘阵列的五分之一，有效地提高了传感性能。此外，纳米盘的厚度变化几乎不会影响这种基于 ITO 的纳米结构的传感性能，确保了在制备过程中有良好的容差。我们使用模板转移和真空沉积技术来制造传感器船，以实现大面积和低成本的纳米结构制备。传感性能用于检测免疫球蛋白 G（IgG）蛋白分子，促进了等离子体纳米结构在无标记生物医学研究和即时诊断中的广泛应用。介电材料的引入有效地降低了 FWHM，但牺牲了灵敏度。因此，利用结构配置或引入其他材料来产生模式耦合和杂化是提供局域场增强和有效调节的有效方法。
