Nanomaterials (Sep 2024)

The Fabrication of Gold Nanostructures as SERS Substrates for the Detection of Contaminants in Water

  • Cristhian A. Visbal,
  • Wilkendry Ramos Cervantes,
  • Lorena Marín,
  • John Betancourt,
  • Angélica Pérez,
  • Jesús E. Diosa,
  • Luis Alfredo Rodríguez,
  • Edgar Mosquera-Vargas

DOI
https://doi.org/10.3390/nano14181525
Journal volume & issue
Vol. 14, no. 18
p. 1525

Abstract

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Gold nanostructures (AuNSs) were used to fabricate surface-enhanced Raman spectroscopy (SERS) substrates. These AuNSs were produced using the solid-state dewetting method from thin films. The fragmentation process was studied at 300 °C, with durations of thermal treatment of 1, 3, 6, and 12 h. These SERS substrates were then employed to detect Rhodamine B (RhB) as the model analyte, simulating a contaminant in the water at a concentration of 5 ppm. The morphology of the AuNSs was examined using SEM, which revealed a spheroidal shape that began to coalesce at 12 h. The size of the AuNSs was estimated to range from 22 ± 7 to 24 ± 6 nm, depending on the annealing time. The localized surface plasmon resonance of the AuNSs was determined using absorption spectroscopy, showing a shift as the annealing time increased. The SERS signals of RhB adsorbed on the AuNS substrates were validated by performing a 10 × 10 point map scan over each sample surface (1, 3, 6, and 12 h), and a comparative analysis showed no significant differences in the positions of the bands; however, variations in intensity enhancement ranged from 5 to 123 times at 6 and 1 h, respectively.

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