Research Center for Applied Sciences, Academia Sinica , 128, section 2, Academia Road, Nangkang, Taipei 11529, Taiwan.
ACS Nano. 2012 Apr 24;6(4):2931-9. doi: 10.1021/nn3001142. Epub 2012 Apr 2.
Nanostructure-based sensors are capable of sensitive and label-free detection for biomedical applications. However, high-throughput and low-cost fabrication techniques are the main issues which should be addressed. In this study, chip-based nanostructures for intensity-sensitive detection were fabricated and tested using a thermal-annealing-assisted template-stripping method. Large-area uniform nanoslit arrays with a 500 nm period and various slit widths, from 30 to 165 nm, were made on plastic films. A transverse magnetic-polarized wave in these gold nanostructures generated sharp and asymmetric Fano resonances in transmission spectra. The full width at half-maximum bandwidth decreased with the decrease of the slit width. The narrowest bandwidth was smaller than 10 nm. Compared to nanoslit arrays on glass substrates using electron-beam lithography, the proposed chip has a higher intensity sensitivity up to 10367%/RIU (refractive index unit) and reaches a figure of merit up to 55. The higher intensity sensitivity for the template-stripped nanostructure is attributed to a smoother gold surface and larger grain sizes on the plastic film, which reduces the surface plasmon propagation loss.
基于纳米结构的传感器能够实现生物医学应用中的敏感和无标记检测。然而，高通量和低成本制造技术是需要解决的主要问题。在这项研究中，使用热退火辅助模板剥离法制造和测试了用于强度敏感检测的基于芯片的纳米结构。在塑料薄膜上制造了大面积均匀的纳米狭缝阵列，其周期为 500nm，狭缝宽度从 30nm 到 165nm 不等。在这些金纳米结构中，横磁偏振波在传输光谱中产生了尖锐和非对称的 Fano 共振。半峰全宽随狭缝宽度的减小而减小。最窄的带宽小于 10nm。与使用电子束光刻的玻璃衬底上的纳米狭缝阵列相比，所提出的芯片具有高达 10367%/RIU（折射率单位）的更高强度灵敏度，并达到高达 55 的品质因数。模板剥离纳米结构的更高强度灵敏度归因于塑料薄膜上更光滑的金表面和更大的晶粒尺寸，这减少了表面等离子体传播损耗。
