SERS study of fluorescent and non-fluorescent flavonoids: what is the role of excitation wavelength on SERS optical response?
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Study of colorful compounds using Raman spectrometry can reveal crucial issues especially if fluorescent background is present. Fluorescence effect in flavonoids is shifted to higher wavelengths by the excited state intramolecular proton transfer. Therefore, new peaks arise in the visible spectral range. In this work, four flavonoids (flavone, 3-hydroxyflavone, chrysin and quercetin) are studied in the form of pure compounds in solid state and after adsorption on gold surface. Four excitation wavelengths 532, 633, 785, and 1064 nm are tested for normal Raman and surface-enhanced Raman scattering spectra of used flavonoids. Some of these flavonoids namely chrysin and quercetin exhibited high fluorescence background in normal Raman spectra and, therefore, it was not possible to obtain their good quality spectra using visible excitations. SERS spectrometry allowed detecting and identifying small amount of the colorful compounds and significantly reducing fluorescence background. Characteristic spectral bands were observed using SERS spectrometry at spectra of both fluorescent and non-fluorescent flavonoids.
KeywordsSERS Gold Flavone 3-Hydroxyflavone Chrysin Quercetin
Financial support was from specific university research (MSMT no. 21-SVV/2018—A2_FCHI_2018_028).
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Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
- Dendisová M, Havránek L, Ončák M, Matějka P (2013) In situ SERS study of azobenzene derivative formation from 4-aminobenzenethiol on gold, silver, and copper nanostructured surfaces: what is the role of applied potential and used metal? J Phys Chem C 117:21245–21253. https://doi.org/10.1021/jp4040985 CrossRefGoogle Scholar
- Dendisova-Vyskovska M, Broncova G, Clupek M, Prokopec V, Matejka P (2012) In situ SERS spectroelectrochemical analysis of antioxidants deposited on copper substrates: what is the effect of applied potential on sorption behavior? Spectrochim Acta Part A Mol Biomol Spectrosc 99:196–204. https://doi.org/10.1016/j.saa.2012.09.017 CrossRefGoogle Scholar
- Dendisova-Vyskovska M, Kokaislova A, Oncak M, Matejka P (2013) SERS and in situ SERS spectroscopy of riboflavin adsorbed on silver, gold and copper substrates. Elucidation of variability of surface orientation based on both experimental and theoretical approach. J Mol Struct 1038:19–28. https://doi.org/10.1016/j.molstruc.2013.01.023 CrossRefGoogle Scholar
- Kokaislova A, Brazdova S, Prokopec V, Clupek M, Cejkova J, Matejka P (2009) Preparation of SERS-active copper substrates by cathodic reduction and evaluation of their structure by atomic force microscopy. Chem Listy 103:246–250Google Scholar
- Lakowicz JR et al (2004) Advances in surface-enhanced fluorescence. J Fluoresc 14:425–441. https://doi.org/10.1023/B:JOFL.0000031824.48401.5c CrossRefGoogle Scholar