title: High performance gold nanorods and silver nanocubes in surface-enhanced Raman spectroscopy of pesticides.
abstract: The behavior of Au nanorods and Ag nanocubes as analytical sensors was evaluated for three different classes of herbicides. The use of such anisotropic nanoparticles in surface-enhanced Raman scattering (SERS) experiments allows the one to obtain the spectrum of crystal violet dye in the single molecule regime, as well as the pesticides dichlorophenoxyacetic acid (2,4-D), trichlorfon and ametryn. Such metallic substrates show high SERS performance at low analyte concentrations making them adequate for use as analytical sensors. Density functional theory (DFT) calculations of the geometries and vibrational wavenumbers of the adsorbates in the presence of silver or gold atoms were used to elucidate the nature of adsorbate-nanostructure bonding in each case and support the enhancement patterns observed in each SERS spectrum.
authors.affiliation: Instituto de Química, Universidade de São Paulo, CP 26.077, 05513-970, São Paulo, SP, Brazil.
authors.forename: Jean Claudio Santos
authors.initials: JC
authors.lastname: Costa
authors.forename: Rômulo Augusto
authors.initials: RA
authors.lastname: Ando
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Sant'Ana
authors.forename: Liane Marcia
authors.initials: LM
authors.lastname: Rossi
authors.forename: Paulo Sérgio
authors.initials: PS
authors.lastname: Santos
authors.forename: Márcia Laudelina Arruda
authors.initials: ML
authors.lastname: Temperini
authors.forename: Paola
authors.initials: P
authors.lastname: Corio
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014227:Triazines / Q000032:analysis / Q000737:chemistry; D014236:Trichlorfon / Q000032:analysis / Q000737:chemistry
chemical_list: D010575:Pesticides; D014227:Triazines; C100057:ametryne; D015084:2,4-Dichlorophenoxyacetic Acid; D012834:Silver; D006046:Gold; D014236:Trichlorfon