Photooxidative Polymerization of Pyrrole from Photosystem I Proteins

The photosystem I (PSI) protein complex is increasingly being utilized because of its robust photoelectrochem-ical properties. The oxidative ability of the P700 reaction site of the protein is less studied than the reductive capabilities of the FB reaction site. As shown herein, the oxidation potential of P700 is robust enough to initiate an oxidative polymerization of the redox monomer, pyrrole. This manuscript reports the first photoactive and conductive protein-polymer composite using extracted, unmodified PSI protein to perform the polymerization process. The polymerization technique consists of adding a monomer and a dopant to a solution of PSI and illuminating the sample with simulated sunlight. Successful polymerization of pyrrole from PSI is confirmed by the combination of infrared spectroscopy, visual observation, thermogravimetric analysis, contact angle measurements, and conductivity measurements. A stable composite between the protein and polymer is indicated by SDS-PAGE and is further supported by photoelectrochemical properties that are opposite in current and potential from those of PSI alone.

Automated summary

This study demonstrates the successful utilization of PSI protein in photoactive polymerization, creating a photoactive and conductive protein-polymer composite. The stability and successful reaction of this composite material are confirmed through various testing methods.