LAUSR

Size regulation of polydopamine nanoparticles (PDA NPs) is vital to melanin-inspired materials. The general strategy usually focuses on tuning of the reaction parameters which could affect the dopamine (DA) monomer polymerization process, such as pH, temperature, monomer concentration, etc. The reaction between boronic acids and catechols to form boronic esters has been widely applied in many fields, but little attention has been paid in the size regulation of PDA NPs. Here, we speculated the fine size regulation of PDA NPs can be directly achieved by using boronic acids and Lewis base molecules. It was found that these issues could indeed significantly affect the stability of the boronic esters formed by boronic acids and DA, which may further inhibit the monomer polymerization kinetics and tune the particle size of the resulting PDA NPs. We also found that the several intrinsic properties of PDA NPs such as the free radical scavenging ability, UV spectral absorption, photothermal behaviour and structural color were all changed with the particle size. We believe that this work could provide new opportunities for fabricating melanin-inspired PDA NPs with well controlled size and properties. This article is protected by copyright. All rights reserved.