Continuously-tunable fluorescent polypeptides through a polymer-assisted assembly strategy

Luminogenic materials with tunable fluorescence emission have attracted increasing interest due to their broad applications. Here, we develop a versatile method to continuously tune the packing and fluorescence of organic chromophores through a polymer-assisted assembly (PAA) strategy, affording a catalog of fluorescent polymers with continuously-tunable fluorescence emission. Polypeptides decorated with tetraphenylethene (PBLG-TPE) were synthesized by combining ring-opening polymerization with a post-modification procedure. PBLG-TPE showed hexagonally-packed structures comprised of PBLG α-helices with TPE moieties trapped inside. We demonstrated that the fluorescence of PBLG-TPE could be tuned in a controlled manner by regulating TPE fraction, molecular weight, and temperature, associated with the distance between adjacent PBLG α-helices. Such a polymer-assisted assembly offers a new method to tune the packing and fluorescence of organic chromophores, and a family of fluorescent polymers with continuously-tunable fluorescence emission.