Formation of ABTS radical cation in the presence of silver nanoparticles as revealed by surface-enhanced Raman scattering
| Autor: | García-Leis, Adianez, García-Ramos, José Vicente, Jurasekova, Z., Fabriciova, G., Antalik, Marian, Jancura, Daniel, Sánchez-Cortés, Santiago |
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| Rok vydání: | 2014 |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Espectroscoía, Universidad de la Rioja, Logroño, La Rioja, 9-11 de julio de 2014. PO83; http://www.unirioja.es/espectroscopia2014/ ABTS [2,2¿-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] has been extensively employed to evaluate the free radical trapping capacity of pure compounds and complex mixtures such as biological fluids or foods [1], when it is incubated in presence of a free radical source in the so-called Trolox equivalent antioxidant capacity (TEAC) assay. The latter assay is performed by using a colorimetric experiment, where ABTS is previously oxidized by persulfate to get the radical cation ABTS*+ [2], giving rise to an intense absorbance at 734 nm. In this work we report the formation of the radical cation in the presence of star-shaped silver nanoparticles (AgNS) [3]. ABTS*+ was characterized by surface-enhanced Raman scattering (SERS) and detected at trace concentrations (2 µM). The ABTS*+/AgNS system is proposed here as a reliable substrate to test the antioxidant activity of foods based on the high sensitivity of plasmonic nanostars as an alternative method to the TEAC test |
| Databáze: | OpenAIRE |
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