Related Experiment Video
Updated: Sep 22, 2025
Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst
Published on: June 8, 2016
Photoactive Red Fluorescent SiO2 Nanoparticles Based on Controlled Methylene Blue Aggregation in Reverse
Yamili Toum Terrones1,2, María Fernanda Torresán1, Martín Mirenda1
1Gerencia Química - Instituto de Nanociencia y Nanotecnología (INN - CONICET), Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, CONICET, Av. Gral. Paz 1499, B1650 KNA San Martín, Buenos Aires, Argentina.
Researchers developed a novel synthesis for silica nanoparticles loaded with methylene blue (MB). These nanoparticles efficiently generate singlet oxygen for photodynamic therapy and act as red fluorescent probes.
Area of Science:
- Materials Science
- Nanotechnology
- Photochemistry
Background:
- Methylene blue (MB) is an FDA-approved photosensitizer effective for generating singlet oxygen (1O2).
- Encapsulating photosensitizers in nanoparticles can enhance their therapeutic efficacy and stability.
- Controlling dye aggregation within nanoparticles is crucial for maintaining photoactivity.
Purpose of the Study:
- To develop a reverse microemulsion synthesis for incorporating methylene blue into SiO2 nanoparticles.
- To control dye aggregation within the nanoparticle core for efficient 1O2 generation.
- To characterize the photophysical and photochemical properties of the resulting MB@SiO2 NPs for theranostic applications.
Main Methods:
- Utilized a reverse microemulsion technique to synthesize hydrophobic-core/hydrophilic-shell SiO2 nanoparticles.
- Incorporated methylene blue (MB) into the nanoparticle matrix under varying synthesis conditions.
- Employed real-time UV-vis absorption spectroscopy to monitor dye aggregation during synthesis.
Main Results:
- Successfully synthesized silica nanoparticles (MB@SiO2 NPs) with an average diameter of ~50 nm.
- Achieved high local MB concentration (~10-2 M) per nanoparticle with moderate dye aggregation.
- Demonstrated high singlet oxygen photogeneration efficiency (ΦΔ = 0.30 ± 0.05) and red fluorescence (ΦF ~ 0.02).
Conclusions:
- The reverse microemulsion method provides a viable strategy for creating photoactive MB@SiO2 NPs.
- The synthesized nanoparticles exhibit promising characteristics for photodynamic therapy (PDT) applications.
- These MB@SiO2 NPs can serve as theranostic nano-objects, combining therapeutic and diagnostic capabilities.
