Quantitative Enhanced Raman Scattering of Labeled DNA from Gold and Silver Nanoparticles

Authors

  • Robert J. Stokes Dr.,

    1. Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK, Fax: (+44) 141-552-0876
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    • These authors contributed equally this work.

  • Alexandra Macaskill Dr.,

    1. Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK, Fax: (+44) 141-552-0876
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    • These authors contributed equally this work.

  • P. Johan Lundahl,

    1. Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK, Fax: (+44) 141-552-0876
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  • W. Ewen Smith Prof.,

    1. Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK, Fax: (+44) 141-552-0876
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  • Karen Faulds Dr.,

    1. Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK, Fax: (+44) 141-552-0876
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  • Duncan Graham Prof.

    1. Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK, Fax: (+44) 141-552-0876
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    • These authors contributed equally this work.


Abstract

Surface-enhanced resonance Raman scattering (SERRS) from silver nanoparticles using 514.5-nm excitation has been shown to offer huge potential for applications in highly sensitive multiplexed DNA assays. If the technique is to be applied to real biological samples and integrated with other methods, then the use of gold nanoparticles and longer wavelengths of excitation are desirable. The data presented here demonstrate that dye-labeled oligonucleotide sequences can be directly detected by SERRS using gold nanoparticles in a quantitative manner for the first time. The performance of gold and silver nanoparticles as SERRS substrates was assessed using 514.5-, 632.8-, and 785-nm excitation and a range of 13 commercially available dye-labeled oligonucleotides. The quantitative response allowed the limit of detection to be determined for each case and demonstrates that the technique is highly effective, sensitive, and versatile. The possibility of excitation at multiple wavelengths further enhances the multiplexing potential of the technique. The importance of effectively combining the optical properties of the nanoparticle and the dye label is demonstrated. For example, at 632.8-nm excitation, the dye BODIPY TR-X and gold nanoparticles make a strong SERRS combination with very little background fluorescence. This study allows the choice of nanoparticle and dye label for particular experimental setups, and significantly expands the applicability of enhanced Raman scattering for use in many disciplines.

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