Dendrimer-based magneto-plasmonic nanosorbents for water quality monitoring using surface-enhanced Raman spectroscopy

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2022-12, Vol.283, p.121730, Article 121730
• Main Authors: Fernandes, Tiago, Martins, Natércia C.T., Daniel-da-Silva, Ana L., Trindade, Tito
• Format: Article
• Language: English
• Subjects: Dendrimers; Gold nanoparticles; Magnetite; Raman spectroscopy; Water quality
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2022.121730

Dendrimer-based magneto-plasmonic conjugates containing anisotropic Au nanoparticles for water contaminants detection using surface-enhanced Raman scattering (SERS). [Display omitted] •Hybrid dendrimer-based magneto-plasmonic materials based on Fe3O4 and Au nanostars.•Fast collection from water allowing the simultaneous uptake and SERS probing of pesticides.•Versatile systems that can used under multiple analytical conditions, namely by a portable Raman device. In this work, we report the synthesis of magneto-plasmonic dendrimer-based nanosorbents containing Au nanostars and we demonstrate that they can be used as versatile optical sensors for the detection of pesticides in spiked water samples. The magnetic hybrid nanoparticles were obtained by conjugating silica-functionalized G5-NH2 PAMAM dendrimers to silica-coated magnetite cores. The resulting magnetic-PAMAM conjugates were then used to reduce and sequester Au seeds for the subsequent in situ growth of Au nanostars. The dendrimer-based magneto-plasmonic substrates containing the Au anisotropic nanophases were then investigated regarding their ability to monitor water quality through surface-enhanced Raman scattering (SERS) spectroscopy. As a proof-of-concept, the ensuing multifunctional materials were investigated as SERS probing systems to detect dithiocarbamate pesticides (ziram and thiram) dissolved in water samples. It was observed that the magneto-plasmonic hybrid materials enhance the Raman signal of these pesticides under variable operational conditions, suggesting the versatility of these systems for water quality monitoring. Moreover, a detailed analysis of the SERS data was accomplished to predict the adsorption profile of the dithiocarbamate pesticides to the Au surface.