1716
(Europe Section Alessandro Volta Medal) Electrochemical SERS on Nanostructured Surfaces and its Application to DNA Detection and Discrimination
the surface enhancement on SSV surfaces by varying the film thickness and template sphere diameter and by looking at the angular dependence. The intensity of the SER spectra varies with all of these factors indicating that the precise geometry of the structured surface and the excitation of surface plasmons is important [1]. These surfaces can be used for practical applications in SERS, for example in in situ electrochemical studies [2].
Combining the extreme surface sensitivity of SERS with control of the electrode potential we have been able to use these SSV electrodes as a platform for very sensitive detection and discrimination of DNA sequences [3]. This new method uses a probe DNA strand bound to the gold SSV electrode surface and then uses the SERS to detect the presence of double stranded DNA formed when the target DNA binds to the probe strand at the surface. By sweeping the applied potential cathodic the dsDNA strands can be made to separate and the potential at which this separation occurs can be used to discriminate perfectly matched dsDNA from mismatched cases thus allowing discrimination of single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs) [4].
References
[1] P. N. Bartlett, J. J. Baumberg, S. Coyle and M. Abdelsalem, Faraday Discuss. 2004, 125, 117.
[2] M. Abdelsalam, P. N. Bartlett, A. E. Russell, J. J. Baumberg, E. J. Calvo, N. G. Tognalli and A. Fainstein, Langmuir 2008, 24, 7018.
[3] S. Mahajan, J. Richardson, T. Brown, and P. N. Bartlett, J. Am. Chem. Soc. 2008, 130, 15589.
[4] D. K. Corrigan, N. Gale, T. Brown and P. N. Bartlett, “Analysis of short tandem repeats (STRs) using SERS monitoring and electrochemical melting”, Angew. Chemie, Int. Edn., 2010, 24, 5917.