Electrospectral SERS detection of cysteine using copper electrode

Abstract

Electrospectral surface-enhanced Raman spectroscopy (SERS) was used to measure SERS spectra of cysteine (amino acid) using SERS-active copper electrode under controlled electrode polarization. The experiments include electrostatic adsorption of cysteine molecules on the nanoroughened copper electrode with further registration of the SERS signal. Copper was selected due to its competitive enhancing properties compared to those for SERS-active materials based on silver and gold. Optimization of conditions for preparation of SERS-active copper electrode (i.e., electrochemical surface roughening in order to create nano-sized areas) with the best enhancing properties has been carried out. The adsorption of cysteine on the copper electrode surface was studied by SERS as a function of electrode polarization potential and pH value of the solution. It was found that the two cysteine molecules can experience electro-oxidation with irreversible formation of cystine and this transformation is indicated by the appearance of S-S stretching in the SERS spectrum.
The work was supported by the Scholarships of the President of the Russian Federation to young scientists and graduate students (SP-1115.2021.4).

Speaker

Natalia E. Markina
Saratov State University
Russia

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