Synthesis of a SERRS substrate based on TiO2 nanotubes films decorated with Ag nanoparticles for anthocyanins species determination in grape skin extracts

Autor(es)

Sarto, Gabrielle ; Cervantes, Thiago N. M. ; Slonski, Maiara M. ; V. Martins, Joao ; Soto, Pablo C. ; de Santana, Henrique ; de Almeida, Lucio C.

• Tipo de documento: Artigo Científico
• Fonte: VIBRATIONAL SPECTROSCOPY; v. 134, p. 12-pg., 2024-07-14.

Resumo

The synthesis of TiO2 nanotubes film decorated with Ag nanoparticles (TiO2NTs/AgNPs) and its potential applicability as a SERRS (Surface-Enhanced Raman Resonance Scattering) substrate for detection and speciation of anthocyanins species in grape skin extracts is reported. Preliminary spectrophotometric analysis in the UV-Vis region allowed to identify the maximum absorption bands at 527 and 620 nm, related to the flavylium cation (AH+) and quinoidal base (A-), respectively. The increase in the ratio AgNPs/extract concentration in colloidal solutions of AgNPs promoted the intensification of the vibrational modes of anthocyanins species, due to the SERRS effect. From deconvolutions of these SERRS spectra, a linear relationship (R2 = 0.993) for the intensity ratio of the vibrational modes A-/AH+ (i.e., for the ratio 1631-1640/1648-1659 cm-1) as a function of the grape skin extract dilutions at colloidal solutions of AgNPs was found. The deposition of the extracts onto TiO2NTs/ AgNPs surface promoted an additional SERRS signal intensification for A- in detriment to AH+. The deconvolution of these SERRS spectra showed again a linear relationship (R2 = 0.999) between the intensity bands ratio A-/AH+ and grape skin extract dilutions in the range of 0.1-1.0 %. The SERRS technique using the TiO2NTs/ AgNPs substrate was more sensitive for anthocyanins quantification compared to the spectrophotometric one. The results revealed that the TiO2NTs/AgNPs films are versatile, efficient, and promising platforms for SERRS quantification and speciation of anthocyanin species in situ. (AU)

• Processo FAPESP: 14/50945-4 - INCT 2014: Instituto Nacional de Tecnologias Alternativas para Detecção, Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático