abstract
Resistance of pathogenic micro-organisms to conventional antibiotics is an essential issue for public health. The presence of such pharmaceuticals in aquatic ecosystems has been of major concern for which remediation and ultra-sensitive monitoring methods have been proposed. A less explored strategy involves the application of multifunctional nanosorbents for the uptake and subsequent detection of vestigial contaminants. In this study, colloidal nanoparticles (NPs) of iron oxide and gold were encapsulated in multi-layers of a charged polyelectrolyte (PEI: polyethyleneimine), envisaging the effective capture of tetracycline (TC) and its subsequent detection by Surface Enhanced Raman Scattering (SERS). Adsorption studies were performed by varying operational parameters, such as the solution pH and contact time, in order to evaluate the performance of the nanosorbents for the uptake of TC from water. While the magnetic nanosorbents with an external PEI layer (Fe3O4@PEI and Fe3O4@ PEI-Au@PEI particles) have shown better uptake efficiency for TC, these materials showed less SERS sensitivity than the Fe3O4@PEI-Au nanosorbents, whose SERS sensitivity for TC in water has reached the limit of detection of 10 nM. Thus, this study highlights the potential of such magneto-plasmonic nanosorbents as multi-functional platforms for targeting specific contaminants in water, by taking into consideration both functionalities investigated: the removal by adsorption and the SERS detection across the nanosorbents' surfaces.
keywords
ENHANCED RAMAN-SPECTROSCOPY; IRON-OXIDE NANOPARTICLES; SERS DETECTION; ANTIBIOTICS; ADSORPTION; TETRACYCLINE; REMOVAL; OXYTETRACYCLINE; NANOSTRUCTURES; SORBENTS
subject category
Science & Technology - Other Topics
authors
Pinheiro, PC; Fateixa, S; Daniel-da-Silva, AL; Trindade, T
our authors
acknowledgements
P. Pinheiro thanks Fundacao para a Ciencia e Tecnologia (FCT) for the PhD grant SFRH/BD/96731/2013. Ana L. Daniel-da-Silva acknowledges FCT for the research contract under the Program 'Investigador FCT' 2014. The costs resulting from the FCT hirings is funded by national funds (OE), throug FCT, I.P. in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES.