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Identifying high performance gold nanoshells for singlet oxygen generation enhancement
Sajid Farooq1, Renato E de Araujo2
1Institute of Innovation and Technology, University of Pernambuco, Recife, Brazil; Department of Electronic and System, Federal University of Pernambuco, Recife, Brazil.
Photodiagnosis and Photodynamic Therapy
|August 3, 2021
Summary
Optimized gold nanoshells significantly boost singlet oxygen (1O2) production for photodynamic therapy (PDT). This metal-enhanced singlet oxygen generation improves photosensitizer efficacy by over 320% in Methylene Blue solutions.
Area of Science:
- Nanotechnology
- Biomedical Engineering
- Photochemistry
Background:
- Metallic nanostructures enhance singlet oxygen (1O2) production in photosensitizers for photodynamic therapy (PDT).
- Effective PDT requires plasmonic nanoparticles with high scattering efficiency, electric field enhancement, and overlapping plasmon peaks with photosensitizer absorption spectra.
- Optimizing nanoparticle structure is crucial for maximizing metal-enhanced singlet oxygen generation.
Purpose of the Study:
- To optimize gold nanoshell (Au NS) structure (silica core radius, gold shell thickness) for enhanced singlet oxygen production by Methylene Blue (MB) photosensitizer.
- To evaluate the impact of Au NS dimensions on plasmonic properties, scattering efficiency, and localized electric field intensity.
- To experimentally quantify the metal-enhanced singlet oxygen generation by optimized Au NS in MB solutions and assess influencing factors like irradiation time and concentration.
Main Methods:
- 3D Full-wave electromagnetic field analysis to simulate and optimize Au NS plasmonic properties.
- Fabrication and characterization of Au NS with varying silica core radius and gold shell thickness.
- Experimental quantification of singlet oxygen generation using Methylene Blue and optimized Au NS under irradiation.
- Investigation of the effects of irradiation time and Au NS concentration on singlet oxygen yield.
Main Results:
- Optimized 40/20 nm silica core/gold shell Au NS exhibited 75% scattering efficiency and up to 35-fold electric field enhancement.
- Experimental results demonstrated a 320% increase in 1O2 production in Methylene Blue solutions using the optimized Au NS.
- Metal-enhanced singlet oxygen generation was confirmed, with its efficiency influenced by irradiation time and Au NS concentration.
Conclusions:
- Engineered gold nanoshells significantly enhance singlet oxygen production for photodynamic therapy applications.
- The study provides a methodology for selecting high-performance plasmonic nanoparticles for metal-enhanced singlet oxygen generation.
- Optimized plasmonic nanostructures hold promise for improving the efficacy of photosensitizer-based PDT treatments.
