Characterization of polydopamine thin films deposited at short times by the autoxidation of dopamine

Published

July 9, 2013

Author(s)

Rebecca A. Zangmeister, Todd A. Morris, Michael J. Tarlov

Abstract

Current interest in melanin films derived from the autoxidation of dopamine stems from their use as a universal adhesion layer. Here we report chemical and physical characterization of polydopamine films deposited on gold surfaces from stirred basic solutions at times ranging from 2 to 60 min, with a focus on times ≤10 min. Data from Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and electrochemical methods suggest the presence of starting (dopamine) and intermediate (C=N-containing tautomers of quinone and indole) species in the polydopamine films at all deposition times. A uniform overlayer analysis of the XPS data indicates that film thickness increased linearly at short deposition times of ≤10 min. At deposition times ≥10 min, the films appeared largely continuous with surface roughness ≈ ≤ 2 nm, as determined by atomic force microscopy (AFM). Pinhole-free films, as determined by anionic redox probe measurements, required deposition times of 60 min or greater.

Citation

Langmuir

Volume

29

Issue

27

Pub Type

Journals

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DOI Link

Keywords

Dopamine, polydopamine, melanin, FTIR, AFM, XPS, electrochemical analysis, morphology.

Citation

Zangmeister, R. , Morris, T. and Tarlov, M. (2013), Characterization of polydopamine thin films deposited at short times by the autoxidation of dopamine, Langmuir, [online], https://doi.org/10.1021/la400587j (Accessed December 26, 2024)