Morphology-tunable polydopamine nanoparticles and their application in Fe3+ detection

Abstract In this work, we discovered the morphology transformation property of polydopamine (PDA) nanomaterials, the addition of Fe 3+ initiated the dramatic morphology transformation of PDA dots from aggregated plate-like to uniform willow-leaf-like morphology. Further study revealed that this fascinating morphology transformation process could be attributed to the oxidative nature and coordination characteristic of Fe 3+ . This is the first report on the morphology transformation ability of PDA, and a probable self-assembled mechanism was proposed to explain this issue. Besides, we noticed that morphological and fluorescent properties of PDA dots were closely related, thus a fluorescent Fe 3+ detection method was presented based on the morphology-tunable PDA dots. With the proposed method, selective Fe 3+ detection was achieved with a wide linear dynamic range of 10 μM to 1 mM. Furthermore, since the morphology tuning behavior of PDA dots was easy to operate, we anticipate this ability will find significant utility in sensing, drug delivery, and tissue engineering.