Building‐Block Diversity in Polydopamine Underpins a Multifunctional Eumelanin‐Type Platform Tunable Through a Quinone Control Point

Abstract Rational approaches to engineering polydopamine films with tailored properties for surface coating and functionalization are currently challenged by the lack of detailed information about the polymer structure and the mechanism of buildup. Using an integrated chemical and spectroscopic approach enables the demonstration of: a) a three‐component structure of polydopamine, comprising uncyclized (catecholamine) and cyclized (indole) units, as well as novel pyrrolecarboxylic acid moieties; b) remarkable variations in the relative proportions of the cyclized and uncyclized units with starting dopamine concentration; c) the occurrence of oligomer components up to the tetramer level; d) the covalent…