Insights into the Aggregation/Deposition and Structure of a Polydopamine Film

• DOI: 10.1021/la5026608
• Publication Date: 2014-09-27T14:26:02Z
• Authors: Yonghui Ding; Lu-Tao Weng; Meng Yang; Zhilu Yang; Xiong Lu; Nan Huang; Yang Leng
• Keywords: Trimer; Moiety; Deposition

Surface-adherent polydopamine (PDA) films as multifunctional coatings can be easily deposited onto a wide range of materials through dopamine self-polymerization. However, lack in-depth understanding PDA aggregation and deposition processes definite structure elucidation make it challenging to tailor the surface characteristic functionality films. Herein, we demonstrate that characteristics readily tuned by controlling competitive interplay between in solution on substrate. Moreover, structural investigation using analytical tools such X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), matrix-assisted laser desorption/ionization (MALDI-MS) allows us propose new model for building block. The (DHI)2/PCA trimer complex, which consists two 5,6-dihydroxyindole (DHI) units one pyrrolecarboxylic acid (PCA) moiety, is definitely identified primary block PDA, its formation steered covalent interactions initial stages polymerization. In latter stages, complexes are further linked primarily noncovalent build up supramolecular PDA. This study provides insights into mechanisms buildup.