Facile Preparation of Near Infrared-Luminescent Protein Complexes with Conjugated Polymers Consisting of Boron Azobenzene Units

Abstract

We report herein facile preparation of near infrared (NIR)-luminescent protein complexes with conjugated polymers. We have discovered that solid-state luminescence in the NIR region can be obtained from the series of conjugated polymers consisting of boron azobenzene complexes. We demonstrate in this paper that protein molecules can be modified through adsorption with the boron azobenzene-containing conjugated polymers simply by mixing in an aqueous buffer and subsequently purification with filtration followed by freeze drying. The modified protein complexes can exhibit NIR emission in the buffer and high dispersibility. In particular, comparing to the complex with indocyanine green (ICG), which is a conventional NIR-luminescent dye, polymer-modified protein complexes showed higher resistance to photobleaching. Finally, by using lipase as a scaffold, we confirmed that enzymatic activity can be detected after polymer modification.