title: Real-time surface-enhanced Raman spectroscopy monitoring of surface pH during electrochemical melting of double-stranded DNA.
abstract: The application of a negative potential ramp at a double-stranded DNA (dsDNA) functionalized electrode surface results in the gradual denaturation of the DNA in a process known as electrochemical melting. The underlying physical chemistry behind electrochemically driven DNA denaturation is not well understood, and one possible mechanism is a change in local pH at the electrode surface. We demonstrate that by coimmobilization of p-mercaptobenozic acid at a dsDNA-functionalized electrode surface, it is possible to monitor both DNA denaturation and the local pH simultaneously using surface-enhanced Raman spectroscopy. We find that the local pH at the electrode surface does not change as the applied potential is scanned negative and the dsDNA denatures. We therefore conclude that in these experiments electrochemical melting is not caused by electrochemically driven local pH changes.
authors.affiliation: School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Johnson
authors.forename: James A
authors.initials: JA
authors.lastname: Richardson
authors.forename: Tom
authors.initials: T
authors.lastname: Brown
authors.forename: Philip N
authors.initials: PN
authors.lastname: Bartlett
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D006863:Hydrogen-Ion Concentration; D009691:Nucleic Acid Denaturation; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D004247:DNA