Extraordinary sensitivity enhancement of Ag-Au alloy nanohole arrays for label-free detection of Escherichia Coli
| Autor: | Ki-Hun Jeong, Myeong-Su Ahn, Charles Soon Hong Hwang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Detection limit
0303 health sciences Materials science Nanostructure business.industry Alloy Extraordinary optical transmission engineering.material 01 natural sciences Atomic and Molecular Physics and Optics Nanoimprint lithography law.invention 010309 optics 03 medical and health sciences law 0103 physical sciences engineering Optoelectronics Thin film business Refractive index Plasmon 030304 developmental biology Biotechnology |
| Zdroj: | Biomedical Optics Express. 12:2734 |
| ISSN: | 2156-7085 |
| DOI: | 10.1364/boe.420828 |
| Popis: | Alloy nanostructures unveil extraordinary plasmonic phenomena that supersede the mono-metallic counterparts. Here we report silver-gold (Ag-Au) alloy nanohole arrays (α-NHA) for ultra-sensitive plasmonic label-free detection of Escherichia Coli (E. coli). Large-area α-NHA were fabricated by using nanoimprint lithography and concurrent thermal evaporation of Ag and Au. The completely miscible Ag-Au alloy exhibits an entirely different dielectric function in the near infra-red wavelength range compared to mono-metallic Ag or Au. The α-NHA demonstrate substantially enhanced refractive index sensitivity of 387 nm/RIU, surpassing those of Ag or Au mono-metallic nanohole arrays by approximately 40%. Moreover, the α-NHA provide highly durable material stability to corrosion and oxidation during over one-month observation. The ultra-sensitive α-NHA allow the label-free detection of E. coli in various concentration levels ranging from 103 to 108 cfu/ml with a calculated limit of detection of 59 cfu/ml. This novel alloy plasmonic material provides a new outlook for widely applicable biosensing and bio-medical applications. |
| Databáze: | OpenAIRE |
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