title: Surface-enhanced Raman scattering of the adsorption of pesticide endosulfan on gold nanoparticles.
abstract: The absorption of pesticide endosulfan on the surface of gold nanoparticles results from the formation of micrometric structures (1-10 μm) with irregular shape because of the aggregation of individual particles. Such aggregation of gold nanoparticles after absorption of pesticide shows a surface-enhanced Raman scattering (SERS) spectrum, whose intensity depends on the concentration of endosulfan. In addition, the discoloration of the colloidal solution and a diminishing of the intensity of the surface plasmon resonance absorption from individual particles were observed by UV-visible spectroscopy. At the same time, a second band between 638 and 700 nm confirms the formation of aggregates of gold nanoparticles as the concentration of endosulfan increases. Finally, we used the SERS intensity of the S-O stretching vibration at 1239 cm(-1) from the SO3 group as a measure of concentration of pesticide endosulfan. This method could be used to estimate the level of pollution in water by endosulfan in a simple and practical form.
authors.affiliation: a Instituto Politécnico Nacional, CIBA-Tlaxcala , Tepetitla , Tlax , México.
authors.forename: M I
authors.initials: MI
authors.lastname: Hernández-Castillo
authors.forename: O
authors.initials: O
authors.lastname: Zaca-Morán
authors.forename: P
authors.initials: P
authors.lastname: Zaca-Morán
authors.forename: A
authors.initials: A
authors.lastname: Orduña-Diaz
authors.forename: R
authors.initials: R
authors.lastname: Delgado-Macuil
authors.forename: M
authors.initials: M
authors.lastname: Rojas-López
mesh_terms: D000327:Adsorption; D003102:Colloids; D004726:Endosulfan / Q000032:analysis / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010575:Pesticides / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman / Q000379:methods; D020349:Surface Plasmon Resonance; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D003102:Colloids; D010575:Pesticides; D014874:Water Pollutants, Chemical; D014867:Water; D006046:Gold; D004726:Endosulfan
keywords: Gold nanoparticles; SERS; aggregation; endosulfan