Endogenous Oxygen Depletion-Based Emulsion Polymerization Nanospheres for Room-Temperature Phosphorescence...

Area of Science:

• Materials Science
• Chemistry
• Biomedical Engineering

Background:

• Organic room-temperature phosphorescence (RTP) is highly susceptible to quenching by water and oxygen in aqueous environments.
• Existing strategies like nanocrystallization and supramolecular assembly are limited for certain chromophores.

Purpose of the Study:

• To develop a novel strategy for achieving aqueous RTP using endogenous oxygen depletion.
• To create stable and effective aqueous RTP probes for bioimaging applications.

Main Methods:

• Emulsion polymerization was used to create poly(methyl methacrylate) (PMMA) nanospheres (NSs).
• Chromophores with high reactive oxygen species (ROS) generation capabilities were encapsulated within the PMMA NSs.
• The dense, hydrophobic structure of PMMA NSs and high ROS generation suppressed phosphorescence quenching.

Main Results:

• The developed PMMA NSs enabled visible aqueous RTP in an air-exposed environment, unlike nanocrystalline or supramolecular systems.
• Successful bioimaging in subcutaneous, tumor, and lymphatic tissues was demonstrated with high signal-to-background ratios (up to 556).

Conclusions:

• Endogenous oxygen depletion via emulsion polymerization offers a viable strategy for aqueous RTP probes.
• This approach broadens the applicability of organic RTP probes in bioimaging, particularly in aqueous systems.