Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia.
Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky 4, 194064 St. Petersburg, Russia.
Sensors (Basel). 2022 Jul 21;22(14):5455. doi: 10.3390/s22145455.
We studied the surface-enhanced Raman spectra of amino acids -alanine and -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.
我们研究了在毫摩尔浓度的氨基酸溶液中，浸入磷酸盐缓冲盐水（PBS）溶液中的银纳米岛膜（SNF）上的氨基酸 - 丙氨酸和 - 丝氨酸及其混合物的表面增强拉曼光谱。结果表明，由于金属纳米岛膜的静电取向，氨基酸两性离子，氨基酸溶液的光谱与微晶体的参考光谱不同。此外，在吸附在 SNF 上的氨基酸混合物的光谱中观察到非加和峰，这意味着吸附氨基酸之间的分子间相互作用非常显著。结果表明，需要对氨基酸溶液的拉曼光谱进行彻底分析，特别是在存在纳米结构化银表面的 PBS 中，这也可能对研究分子性质和分子间相互作用感兴趣。
