MXene improves the stability and electrochemical performance of electropolymerized PEDOT films

by S. Wustoni, A. Saleh, J.K. El-Demellawi, A. Koklu, A. Hama, V. Druet, N. Wehbe, Y. Zhang, S. Inal
Year: 2020 DOI: 10.1063/5.0023187

Bibliography

MXene improves the stability and electrochemical performance of electropolymerized PEDOT films
S. Wustoni, A. Saleh, J.K. El-Demellawi, A. Koklu, A. Hama, V. Druet, N. Wehbe, Y. Zhang, S. Inal
APL Materials 8 (12), 121105, 2020

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrene sulfonate) (PSS) is the most commonly used conducting polymer in organic bioelectronics. However, electrochemical capacitances exceeding the current state-of-the-art are required for enhanced transduction and stimulation of biological signals. The long-term stability of conducting polymer films during device operation and storage in aqueous environments remains a challenge for routine applications. In this work, we electrochemically synthesize a PEDOT composite comprising the water dispersible two-dimensional conducting material Ti3C2 MXene. We find that incorporating MXene as a co-dopant along with PSS leads to PEDOT:PSS:MXene films with remarkably high volumetric capacitance (607.0 ± 85.3 F cm−3) and stability (capacity retention = 78.44% ± 1.75% over 500 cycles), outperforming single dopant-comprising PEDOT films, i.e., PEDOT:PSS and PEDOT:MXene electropolymerized under the same conditions on identical surfaces. The stability of microfabricated PEDOT:PSS:MXene electrodes is evaluated under different conditions, i.e., when the films are exposed to sonication (∼100% retention over 6 min), upon immersion in cell culture media for 14 days (∆|Z| = 2.13%), as well as after continuous electrical stimulation. Furthermore, we demonstrate the use of a PEDOT:PSS:MXene electrode as an electrochemical sensor for sensitive detection of dopamine (DA). The sensor exhibited an enhanced electrocatalytic activity toward DA in a linear range from 1 µM to 100 μM validated in mixtures containing common interferents such as ascorbic acid and uric acid. PEDOT:PSS:MXene composite is easily formed on conductive substrates with various geometries and can serve as a high performance conducting interface for chronic biochemical sensing or stimulation applications.

Keywords

Electrochemical sensors PEDOT Conductive substrates Stability Continuous cell culture