Plasmonic Au and Ag nanoparticles functionalized with Ln3+ complexes for application as luminescent markers in biological assays

• Grant number: 25/01966-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: March 01, 2025
• End date: September 30, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Hermi Felinto de Brito
• Grantee: Ashley Andersson Santos Santana de Jesus
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/08111-2 - Development of rare earth based light converters: luminescent markers, optical sensors, and amplifiers, AP.TEM

Abstract

In this project, plasmonic gold and silver nanoparticles functionalized with trivalent lanthanide ion coordination compounds (Ln3+) will be developed. The main objective is to investigate the potential of these new nanomaterials as optical markers in biological assays, seeking to improve sensitivity and selectivity in detection. Recent studies demonstrate that the coupling between plasmonic nanoparticles and luminescent Ln3+ compounds significantly enhances their photoluminescent properties. In this context, this doctoral project proposes the synthesis of new plasmonic nanomaterials modified with organosilanes, using the Stöber method, and decorated with Ln3+ coordination compounds, exploring new synthesis methodologies. The obtained nanoparticles will be characterized by several techniques, including thermogravimetry (TG-DTG), X-ray diffraction (XRD), infrared (IR) and Raman absorption spectroscopy, X-ray absorption spectroscopy (EXAFS/XANES), X-ray excited optical luminescence (XEOL), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDS). The photophysical property investigation of the optical markers for biological assays will employ static and time-resolved photoluminescence spectroscopy techniques by semiempirical quantum mechanical calculations and Density Functional Theory (DFT) and toxicity tests. Finally, these new nanomaterials will be studied as optical markers in bioassays. Thus, this project agrees with developing new technologies for developing biosensors with high sensitivity and low detection limits.