Inherently fluorescent polystyrene microspheres for coating, sensing and cellular imaging.

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• Commercially available fluorescent polystyrene (PS) microspheres are vital in biological applications like tracing and flow cytometry.
• Existing microspheres often suffer from organic dye leakage and photobleaching, limiting their utility.
• There is a need for stable, intrinsically fluorescent microspheres without external dye incorporation.

Purpose of the Study:

• To explore the inherent fluorescence of polystyrene-based microspheres.
• To develop a novel method for creating fluorescent microspheres without external fluorophores.
• To investigate the potential applications of these new microspheres in biological imaging and material science.

Main Methods:

• Polystyrene microspheres were modified via a simple chloromethylation reaction.
• The fluorescence mechanism was studied by synthesizing and analyzing p-ethylbenzyl chloride.
• Poly(ethylene glycol) (PEG) was grafted onto the microspheres for biocompatibility assessment.

Main Results:

• Chloromethylation endowed PS microspheres with intrinsic blue fluorescence without external dyes.
• The resulting chloromethylated PS (CMPS) microspheres exhibited stable fluorescence with no observed photobleaching or leaking.
• PEG-grafted CMPS microspheres demonstrated good biocompatibility and could image intracellular Fe3+ via fluorescence quenching.

Conclusions:

• Chloromethylation is an effective method to create intrinsically fluorescent PS microspheres with enhanced stability.
• CMPS microspheres offer perpetual fluorescence and functional handles for further modifications.
• These novel microspheres show promise for advanced bioimaging, diagnostics, and as coating materials.