Influence of L-Dopa adsorption time and concentration on Au nanorods aggregation for SERS quantitative analysis

Author(s)

Oliveira, Tatiana A. ; Martin, Cibely S. ; Rubira, Rafael J. G. ; de Barros, Anerise ; Mazali, Italo O. ; Constantino, Carlos J. L.

• Document type: Journal article
• Source: CURRENT APPLIED PHYSICS; v. 54, p. 7-pg., 2023-10-01.

Abstract

Levodopa (L-Dopa) is an important neurotransmitter from the amino acid family and is also associated with the treatment of Parkinson's disease. The obtention of the L-Dopa SERS signal in colloid is a challenge due to the zwitterionic charge promoting repulsion from nanoparticle surface and leading to poor or not active SERS signal. In this work, SERS signal of L-Dopa was successfully obtained using Au nanorods (AuNRs) covered with a cationic lipid bilayer and using the 785 nm laser line. The UV-Vis extinction, dynamic light scattering, and zeta potential results indicated an influence of L-Dopa adsorption time and L-Dopa concentration on AuNRs aggregation. The SERS signal followed this time dependence, being the characteristic L-Dopa band observed only after 30 min. The L-Dopa quantitative analysis using the standard addition method presented a linear SERS signal at 439 cm-1 with a limit of detection of 6.7 x 10-7 mol L-1 for peak intensity, and 7.9 x 10-7 mol L-1 for band integrated area. (AU)

• FAPESP's process: 22/04020-5 - Optimization of carbendazim fungicide detection via SERS scattering: performance of benchtop vs portable equipment and liquid vs solid substrates
• Grantee: Tatiana Aparecida de Oliveira
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 17/15019-0 - Combination of confocal fluorescence microscopy and surface-enhanced Raman scattering techniques: interaction, detection, and quantification of molecules of interest in biomimetic system.
• Grantee: Cibely da Silva Martin Sonvesso
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/05423-0 - Detection of pesticides (cocktails) used in sugarcane crops and their effect on biological systems
• Grantee: Rafael Jesus Gonçalves Rubira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants