Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films

Abstract

Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries.

Electrically Conductive Polydopamine–Polypyrrole as High Performance Biomaterials for Cell Stimulation in Vitro and Electrical Signal Recording in Vivo

“…PDA/PPY films were prepared according to our previous report. 35 In brief, the PDA/PPY polymerization solution was prepared to have 0.13 M pyrrole, 26 mM dopamine, and 0.1 M NaCl in deionized (DI) water at pH 6. Polymerization solution for PPY films was prepared to have 0.13 M pyrrole and 0.1 M NaCl in DI water at pH 6.…”

“…PPY and PDA/PPY were electrochemically polymerized in a chronopotentiometric mode (1 mA cm -2 ) using either a pyrrole solution or a pyrrole/dopamine (1:0.2 molar ratio) solution, respectively. 35 The electrochemical polymerization of the PPY and PDA/PPY was monitored ( Figure 1a). The potentials during the polymerization of both polymers decreased and remained constant within ~ 50 s, which is indicative of the oxidative electrochemical polymerization of PPY and PDA/PPY on the surface of the electrodes.…”

“…During the chronopotentiometric polymerization, PDA/PPY polymerization potential (~ 0.43 V vs SCE) was slightly lower than PPY polymerization potential (~ 0.68 V), indicating the presence of dopamine facilitated the electrochemical polymerization process by acting as an electron mediator during the oxidative polymerization of pyrrole. 35 Additionally, electrode masses monitored by an electrochemical quartz crystal microbalance (EQCM) revealed the formation and growth of PPY and PDA/PPY films on the surface of the electrodes (Figure 1b). As the deposition time increased, the electrode masses concomitantly increased.…”

Polypyrrole‐coated electrodes show thickness‐dependent stability in different conditions during 42‐day follow‐up in vitro

“…In this article, we show the effect of application environments on the surface characteristics and electrical properties of PPy/DBS‐coated electrodes. Some approaches have been lately reported to improve the initial adhesion of PPy to the underlying substrate material . PPy‐coatings are, however, typically tested for only a few days in cell cultures resulting in a scarcity of long‐term studies on material properties .…”

“…Some approaches have been lately reported to improve the initial adhesion of PPy to the underlying substrate material. 17,28 PPy-coatings are, however, typically tested for only a few days in cell cultures resulting in a scarcity of long-term studies on material properties. 4,5,22 In this study, we present the results of a 42day follow-up of PPy/DBS-coated Pt electrodes with three different coating thicknesses (70 nm, 0.5 mm, and 8 mm).…”