Highly branched Fe3O4@SiO2@Ag-Au microflowers as SERS aptasensors for troponin I analysis

• Grant number: 17/08105-7
• Support type: Scholarships in Brazil - Master
• Effective date (Start): July 01, 2017
• Effective date (End): February 28, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Cooperation agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Italo Odone Mazali
• Grantee: Raisa Siqueira Alves
• Home Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 13/22127-2 - Development of novel materials strategic for integrated analytical devices, AP.TEM

Abstract

Surface-enhanced Raman spectroscopy (SERS) has become a powerful and well-stablished vibrational spectroscopic technique with wide applications in Chemistry, Material Science and related areas. SERS enhances the Raman scattering intensity of molecules adsorbed on rough metal surfaces or metal nanoparticles by several orders of magnitude, overcoming the main drawback in traditional Raman spectroscopy, which is the characteristic weak signal. Herein, the search for effective, highly reproducible and low cost SERS substrates is currently one of the central issues in Raman research. Therefore, this research proposal aims to synthesize highly branched Fe3O4@SiO2@Ag-Au microflowers as high efficiency and recyclable SERS substrates with tunable plasmon resonance. Initially, Fe3O4@SiO2@Ag microflowers will be synthesized by a sonochemical-assisted approach. Next, galvanic replacement will be performed on the silver particles to produce the mixed silver-gold microstructures. The main advantage of tunable plasmon resonance is the possibility to overcome equipment limitations by adjusting the plasmon band of the metal to match the excitation wavelength by controlling the degree of replacement between Ag and Au. The substrates will be then characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), ultraviolet-visible spectroscopy (UV/Vis), X-ray diffraction (XRD) and X-Ray fluorescence (XRF). The enhancement factor of the substrates will be measured by Raman Spectroscopy with rhodamine 6G (R6G) as reference probe. Subsequently, an aptasensor will be assembled from the substrate with the best SERS response for analysis of troponin I, which is a key biomarker for acute myocardial infarction (AMI), one of the lead death causes worldwide according to the World Health Organization (WHO). (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

ALVES, Raisa Siqueira. . 2019. Master's Dissertation.