Red-Light-Driven Atom Transfer Radical Polymerization for High-Throughput Polymer Synthesis in Open Air

Area of Science:

• Polymer Chemistry
• Materials Science
• Bioconjugation Chemistry

Background:

• Photoinduced reversible-deactivation radical polymerization (photo-RDRP) offers precise control over polymer synthesis.
• Existing photo-RDRP methods often require UV/visible light and complex photoredox catalysts.
• There is a need for simpler, more versatile photo-RDRP techniques compatible with biological conditions.

Purpose of the Study:

• To develop the first fully oxygen-tolerant red/NIR-light-mediated photoinduced atom transfer radical polymerization (photo-ATRP).
• To achieve high-throughput synthesis of well-defined polymers and bioconjugates.
• To explore the use of methylene blue as a photoredox catalyst under biologically relevant conditions.

Main Methods:

• Utilized commercially available methylene blue (MB+) as a photoredox catalyst.
• Employed a [X-CuII/TPMA]+ complex as the deactivator in a dual catalytic system.
• Conducted polymerization in an open-air 96-well plate format for high-throughput screening.

Main Results:

• Achieved >90% monomer conversion in under 60 minutes with excellent oxygen tolerance.
• Synthesized well-defined polymers and DNA-polymer bioconjugates with narrow molecular weight distributions (Đ < 1.30).
• Demonstrated successful polymerization triggered by UV to NIR irradiation (395-730 nm) and good biocompatibility.

Conclusions:

• The developed MB+/Cu dual catalytic system represents a significant advancement in photo-RDRP.
• This method simplifies complex polymer synthesis and enables high-throughput creation of advanced materials.
• The oxygen tolerance, broad light-triggering range, and biocompatibility expand applications in materials science and bioconjugation.