Enhancing Surface Sensitivity of Nanostructure-Based Aluminum Sensors Using Capped Dielectric Layers
| Autor: | Hiroaki Misawa, Meng-Lin You, Po-Cheng Tsai, Ming-Yang Pan, Kuang-Li Lee, Pei-Kuen Wei, Kosei Ueno, Xu Shi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Nanostructure Materials science General Chemical Engineering Physics::Optics Nanotechnology 02 engineering and technology Dielectric Article lcsh:Chemistry Condensed Matter::Materials Science 03 medical and health sciences Plasmon business.industry Resonance Fano resonance Metamaterial General Chemistry 021001 nanoscience & nanotechnology Wavelength 030104 developmental biology lcsh:QD1-999 Optoelectronics 0210 nano-technology business Refractive index |
| Zdroj: | ACS Omega ACS Omega, Vol 2, Iss 10, Pp 7461-7470 (2017) |
| ISSN: | 2470-1343 |
| Popis: | The studies of nanostructure-based aluminum sensors have attracted huge attention because aluminum is a more cost-effective plasmonic material. However, the intrinsic properties of the aluminum metal, having a large imaginary part of the dielectric function and a longer electromagnetic field decay length and problems of poor long-term chemical stability, limit the surface-sensing capability and applicability of nanostructures. We propose the combination of capped aluminum nanoslits and a thin-capped dielectric layer to overcome these limitations. We show that the dielectric layer can positively enhance the wavelength sensitivities of the Wood's anomaly-dominant resonance and asymmetric Fano resonance in capped aluminum nanoslits. The maximum improvement can be reached by a factor of 3.5. Besides, there is an optimal layer thickness for the surface sensitivity because of the trade-off relationship between the refractive index sensitivity and decay length. We attribute the enhanced surface sensitivity to a reduced evanescent length, which is confirmed by the finite difference time-domain calculations. The protein-protein interaction experiments verify the high-surface sensitivity of the structures, and a limit of quantification (LOQ) of 1 pg/mL anti-bovine serum albumin is achieved. Such low-cost, highly sensitive aluminum-based nanostructures can benefit various sensing applications. |
| Databáze: | OpenAIRE |
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