Single-Molecule Detection in Nanogap-Embedded Plasmonic Gratings
| Autor: | Avinash Pathak, Keshab Gangopadhyay, Peter V. Cornish, Biyan Chen, Shubhra Gangopadhyay |
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| Rok vydání: | 2015 |
| Předmět: |
DNA/RNA duplex
Microscope Materials science Biomedical Engineering lcsh:Medicine 02 engineering and technology law.invention 03 medical and health sciences Optics law Microscopy Fluorescence microscope Lithography Plasmon 030304 developmental biology 0303 health sciences Total internal reflection fluorescence microscope business.industry lcsh:R Surface plasmon technology industry and agriculture nanogaps epifluorescence microscope 021001 nanoscience & nanotechnology Photobleaching Invited Article single-molecule detection plasmonic gratings 0210 nano-technology business Biotechnology |
| Zdroj: | Nanobiomedicine Nanobiomedicine, Vol 2, Iss, p 8 (2015) Volume 2 Issue Godište 2015 Nanobiomedicine, Vol 2 (2015) |
| ISSN: | 1849-5435 |
| Popis: | We introduce nanogap-embedded silver plasmonic gratings for single-molecule (SM) visualization using an epifluorescence microscope. This silver plasmonic platform was fabricated by a cost-effective nano-imprint lithography technique, using an HD DVD template. DNA/ RNA duplex molecules tagged with Cy3/Cy5 fluorophores were immobilized on SiO2-capped silver gratings. Light was coupled to the gratings at particular wavelengths and incident angles to form surface plasmons. The SM fluorescence intensity of the fluorophores at the nanogaps showed approximately a 100-fold mean enhancement with respect to the fluorophores observed on quartz slides using an epifluorescence microscope. This high level of enhancement was due to the concentration of surface plasmons at the nanogaps. When nanogaps imaged with epifluorescence mode were compared to quartz imaged using total internal reflection fluorescence (TIRF) microscopy, more than a 30-fold mean enhancement was obtained. Due to the SM fluorescence enhancement of plasmonic gratings and the correspondingly high emission intensity, the required laser power can be reduced, resulting in a prolonged detection time prior to photobleaching. This simple platform was able to perform SM studies with a low-cost epifluorescence apparatus, instead of the more expensive TIRF or confocal microscopes, which would enable SM analysis to take place in most scientific laboratories. |
| Databáze: | OpenAIRE |
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