Metal-enhanced ethidium bromide emission: Application to dsDNA detection

• Published in: Chemical physics letters Vol. 480; no. 4; pp. 296 - 299
• Main Authors: Dragan, A.I., Bishop, E.S., Strouse, R.J., Casas-Finet, J.R., Schenerman, M.A., Geddes, C.D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 08.10.2009
• Subjects: NP; SiFs; CW; EB; MEF
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2009.09.005

Deposition of the EB/DNA complex solutions onto the silver nanoparticle surface additionally increases the far-field observable fluorescence ≈180-fold. Ethidium bromide (EB) is a commonly used probe for fluorescence detection and quantification of nucleic acids, since EB forms a highly luminescent complex with dsDNA. Typical detection sensitivity of EB-based assays to dsDNA in solution is about 0.1 μg. With the aim to increase the sensitivity of EB assays we have employed the Metal-Enhanced Fluorescence technology. We show that deposition of the EB/DNA complex solutions onto the silver nanoparticle surface additionally increases the far-field observable fluorescence ≈5-fold, yielding a net fluorescence enhancement factor of ≈180-fold, as compared to the free dye in solution. Subsequently, our approach enables the more sensitive detection of dsDNA.