A Label-Free, Electrochemical SERS Based Assay for the Detection of DNA Hybridization and the Discrimination of Mutations

R. P. Johnson, J. A. Richardson, T. Brown and P. N. Bartlett. J. Am. Chem. Soc. 134 (34), 14099-14107, 2012.


A label-free, SERS based assay for detecting DNA hybridization at an electrode surface and for distinguishing between mutations in DNA is demonstrated. Surface immobilized DNA is exposed to a binding agent that is selective for dsDNA and acts as a reporter molecule. Upon application of a negative potential, the dsDNA denatures into its constituent strands and the changes in the spectra of the reporter molecule are monitored. This method has been used to distinguish between a wild-type, 1563C/T single point mutation and ?F508 triplet deletion in the CTFR gene. The use of dsDNA selective binding agents as reporter molecules in a discrimination assay removes the burden of synthetically modifying the target to be detected, whilst retaining the flexibility in the choice of the reporter molecule.