Fluorescence Self-Quenching of a Mannosylated Poly(p-phenyleneethynylene) Induced by Concanavalin A

We report that static quenching of a mannosylated conjugated polymer (sugar-PPE) by Concanavalin A is positively dependent upon sugar-PPE concentration, that is, the recorded Stern−Volmer constants increase with increasing sugar-PPE concentration. Comparison with data obtained from isothermal titration calorimetry (ITC) display the increased sensitivity of the quenching method when compared to ITC. The proposed mechanism suggests the interaction of two or more chains of PPE with one Con A molecule leading to a quenched sugar-PPE-Con A construct.