Speaker
Description
In recent years, the use of colorants has increased in the food industry around the world, unfortunately, some illegal additives were detected. In particular, Rhodamine B and Rhodamine 6G have been detected in chili products, that is a disturbing situation because these products are part of the Mexicans daily life and could have negative effects on health. An ideal technique to detect these additives is the surface-enhanced Raman scattering (SERS) because it is nondestructive, highly sensitive and easy to reproduce. In this study we analyze a chili powder product, which was purchased in Mexico. We developed two SERS substrate based on Ag nanoparticles (diameter of approximately 40 nm) deposited on a Si wafer by two diferent methods, the first one by Spin Coating and the second one by a a Teflon ring device. Scanning electron microscopy (SEM) demonstrated that Spin Coating allowed to have a homogeneous nanoparticles distribution throughout the silicon wafer surface. The Teflon ring device is a novel device that allowed clusters of Ag nanoparticles to be formed. Energy-dispersive X-ray spectroscopy (EDS) helped us to verify the information about the SERS substrates composition. We detected Rhodamine B and Rhodamine 6G in the chili powder product by both SERS substrates. 1225, 1358 and 1479 cm$^{-1}$ were some of the main signals of Rhodamine B and Rhodamine 6G that were identified by both SERS substrates. The results showed that the SERS substrate based on Ag nanoparticles deposited by the Teflon ring device, got a higher and defined spectrum than the other SERS substrate. This is due to the nanoparticles distribution, clusters allows a greater generation of hot spots than the homogeneous layer of nanoparticles dispersed by Spin Coating.
Reference
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This work was supported by
This work was supported by: Y.L. Casallas-Moreno thanks to the project CONAHCYT-Frontier Science 2023 CF-2023-I-1117, and D. González thanks to the project SIP-20240184 from IPN.
| Keywords | SERS, chili products, illegal additives. |
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| Author approval | I confirm |
| Author will attend | I confirm |
