Water-Processable Polymer Nanoparticles: a New Visible-Light Photosensitizer for Artificial Photosynthesis

Area of Science:

• Green Chemistry
• Biocatalysis
• Photocatalysis

Background:

• Sustainable carbon dioxide (CO2) conversion is crucial for reducing emissions.
• Coenzyme-dependent enzymes require efficient regeneration methods for industrial applications.
• Photocatalytic systems offer a promising avenue for energy-efficient coenzyme regeneration.

Purpose of the Study:

• To develop a cost-effective and efficient method for coenzyme regeneration using solar energy.
• To demonstrate the conversion of bicarbonate to formate using a hybrid bio-photocatalytic system.
• To establish a novel application of conjugated polymers in photocatalysis for biocatalysis.

Main Methods:

• Utilized water-processable nanoparticles (WPNPs) based on conjugated polymers as photosensitizers and mediators.
• Employed triethanolamine (TEOA) as an electron donor for methylviologen dichloride (MV2+) reduction under visible light.
• Integrated the regenerated cofactor with Candida boidinii formate dehydrogenase (CbFDH) for bicarbonate-to-formate conversion.

Main Results:

• Achieved high coenzyme (MV•+) regeneration efficiency of approximately 95% using WPNPs and TEOA.
• Demonstrated enzymatic conversion of sodium bicarbonate (NaHCO3) to formate with a yield of approximately 20%.
• Successfully validated formate production and established a simple nicotinamide adenine dinucleotide (NAD+) to NADH regeneration method.

Conclusions:

• Conjugated polymer-based WPNPs serve as effective photosensitizers and mediators for coenzyme regeneration.
• The developed hybrid system enables efficient solar-driven conversion of bicarbonate to formate.
• This work represents the first use of conjugated polymers in WPNPs for photocatalytic coenzyme regeneration, advancing sustainable chemical synthesis.