Speaker
Description
In recent decades, the excessive use of synthetic pesticides in crop systems has increased, resulting in ecosystem degradation and severe damage to human health. Currently, the mostcommonly used methods to determine pesticide concentration are either complex or limited in accessibility, which would make existing detection methods unsuitable for large-scale applications. Therefore, it is necessary to incorporate simple and portable strategies for separating and preconcentrating the analyte from complex matrices.
Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that can be used to detect and analyze molecules at trace levels. SERS is based on the enhancement of Raman scattering signals that occur when a molecule is in close proximity to certain types of nanostructures, typically metallic nanoparticles. In complex media, such as environmental samples, food matrices, and biological fluids, the detection of trace levels of target analytes using analytical methods can be challenging due to the interference of matrixcomponents. SERS can overcome these limitations by enhancing the Raman signal of the analyte, making it possible to detect low concentrations of the target analyte even in complexmedia. To perform SERS analysis in complexmedia, the target analyte must be separated and preconcentrated to increase the signal-to-noise ratio of the measurement. Several techniques have been developed to achieve this, including solid-phase extraction, liquid- liquid extraction, and membrane filtration. Once the analyte is separated and preconcentrated, it can be analyzed using SERS. As pre-conditioning techniques can be complicated, this work aims to develop SERS substrates integrated with portable strategies for separating analytes from complex media, such as thin layer chromatography and porous or reticulated systems. Gold nanospheres and nanostars were synthesized using modified Turkevich methods and characterized via STEM and UV-Vis. The characteristic fingerprint of organophosphate pesticides was determined using substratescontaining these materials, resulting in enhancement factors of several orders of magnitude.
This work was supported by
The authors thank Manuel Aguilar Franco and María Antonieta Mondragón (CFATA-UNAM) for their technical support during the characterization of the samples. Thanks to CONAHCYT for the granted scholarship.
Reference
Vargas-Zamarripa, M., Rivera, A. A., Sierra, U., Salas, P., Serafín-Muñoz, A. H., & Ramírez-García, G. (2023). Improved charge-transfer resonance in graphene oxide/ZrO2 substrates for plasmonic-free SERS determination of methyl parathion. Chemosphere, 320, 138081.
| Keywords | SERS, Organophosphate pesticides, thin-layer chromatography, Gold Nanostars, quantification of contaminants |
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| Author will attend | I confirm |
