Gold Nanorod Surface-Enhanced Raman Spectroscopy Substrate for l-DOPA Detection: Experimental and Theoretical Approaches

Experimental efforts aimed at detecting levodopa (l-DOPA) using surface-enhanced Raman scattering (SERS) face a persistent challenge in obtaining a SERS signal with negatively charged nanoparticles. This challenge stems from the repulsion between deprotonated l-DOPA in aqueous solution and the charg...

Descripción completa

Detalles Bibliográficos
Autores: de Oliveira, Tatiana Ap. [UNESP], S. Martin, Cibely [UNESP], J.G. Rubira, Rafael [UNESP], de Barros, Anerise, Mazali, Italo O., Zidoi, Luiz P. [UNESP], Batagin-Neto, Augusto [UNESP], Constantino, Carlos J.L. [UNESP]
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/300858
Acceso en línea:http://dx.doi.org/10.1177/00037028251315208
https://hdl.handle.net/11449/300858
Access Level:acceso abierto
Palabra clave:density functional theory
detection
DFT
gold nanoparticles
l-DOPA
SERS
surface-enhanced Raman spectroscopy
Descripción
Sumario:Experimental efforts aimed at detecting levodopa (l-DOPA) using surface-enhanced Raman scattering (SERS) face a persistent challenge in obtaining a SERS signal with negatively charged nanoparticles. This challenge stems from the repulsion between deprotonated l-DOPA in aqueous solution and the charged surface of the nanoparticles, revealing dependencies on time and concentration to achieve the SERS signal. This study explores the adsorption mechanism of l-DOPA on the surface of gold nanorods (AuNRs) covered with a cetrimonium bromide (CTAB) bilayer as a colloidal solution, subsequently dried onto a solid substrate such as glass, silicon, and Au substrate. Experimental findings are supported by density functional theory theoretical calculations. The comparison between experimental and theoretical results highlights that the SERS profile can be attributed to the adsorption of l-DOPA via the catechol ring, leading to the formation of anionic and dianionic species.