Raman Scattering Study of Amino Acids Adsorbed on a Silver Nanoisland Film
Alexey Skvortsov,
Ekaterina Babich,
Andrey Lipovskii,
Alexey Redkov,
Guang Yang,
Valentina Zhurikhina
Affiliations
Alexey Skvortsov
Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia
Ekaterina Babich
Institute of Physics and Mechanics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia
Andrey Lipovskii
Institute of Physics and Mechanics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia
Alexey Redkov
Institute for Problems in Mechanical Engineering of the Russian Academy of Sciences, Boljshoy Prospekt V.O. 61, 199178 St. Petersburg, Russia
Guang Yang
School of Materials Science and Engineering, Shanghai University, Shangda Rd. 99, Baoshan, Shanghai 200444, China
Valentina Zhurikhina
Institute of Physics and Mechanics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia
We studied the surface-enhanced Raman spectra of amino acids D-alanine and DL-serine and their mixture on silver nanoisland films (SNF) immersed in phosphate-buffered saline (PBS) solution at millimolar amino acid concentrations. It is shown that the spectra from the amino acid solutions differ from the reference spectra for microcrystallites due to the electrostatic orientation of amino acid zwitterions by the metal nanoisland film. Moreover, non-additive peaks are observed in the spectrum of the mixture of amino acids adsorbed on SNF, which means that intermolecular interactions between adsorbed amino acids are very significant. The results indicate the need for a thorough analysis of the Raman spectra from amino acid solutions, particularly, in PBS, in the presence of a nanostructured silver surface, and may also be of interest for studying molecular properties and intermolecular interactions.
