Tuning the Chemical and Electrochemical Properties of Paper-Based Carbon Electrodes by Pyrolysis of Polydopamine

Jaqueline F Rocha; Julia C de Oliveira; Jefferson Bettini; Mathias Strauss; Guilherme S Selmi; Anderson K Okazaki; Rafael F de Oliveira; Renato S Lima; Murilo Santhiago

doi:10.1021/acsmeasuresciau.3c00063

Tuning the Chemical and Electrochemical Properties of Paper-Based Carbon Electrodes by Pyrolysis of Polydopamine

ACS Meas Sci Au. 2023 Dec 15;4(2):188-200. doi: 10.1021/acsmeasuresciau.3c00063. eCollection 2024 Apr 17.

Authors

Jaqueline F Rocha^{1

2}, Julia C de Oliveira¹, Jefferson Bettini¹, Mathias Strauss¹, Guilherme S Selmi^{1

3}, Anderson K Okazaki¹, Rafael F de Oliveira^{1

3}, Renato S Lima^{1

2

4

5}, Murilo Santhiago^{1

2}

Affiliations

¹ Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials, São Paulo, Campinas 13083-100, Brazil.
² Federal University of ABC, São Paulo, Santo André 09210-580, Brazil.
³ Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin, São Paulo, Campinas 13083-859, Brazil.
⁴ Institute of Chemistry, University of Campinas, São Paulo, Campinas 13083-970, Brazil.
⁵ São Carlos Institute of Chemistry, University of São Paulo, São Paulo, São Carlos 09210-580, Brazil.

Abstract

Electrochemical paper-based analytical devices represent an important platform for portable, low-cost, affordable, and decentralized diagnostics. For this kind of application, chemical functionalization plays a pivotal role to ensure high clinical performance by tuning surface properties and the area of electrodes. However, controlling different surface properties of electrodes by using a single functionalization route is still challenging. In this work, we attempted to tune the wettability, chemical composition, and electroactive area of carbon-paper-based devices by thermally treating polydopamine (PDA) at different temperatures. PDA films were deposited onto pyrolyzed paper (PP) electrodes and thermally treated in the range of 300-1000 °C. After deposition of PDA, the surface is rich in nitrogen and oxygen, it is superhydrophilic, and it has a high electroactive area. As the temperature increases, the surface becomes hydrophobic, and the electroactive area decreases. The surface modifications were followed by Raman, X-ray photoelectron microscopy (XPS), laser scanning confocal microscopy (LSCM), contact angle, scanning electron microscopy (SEM-EDS), electrical measurements, transmission electron microscopy (TEM), and electrochemical experiments. In addition, the chemical composition of nitrogen species can be tuned on the surface. As a proof of concept, we employed PDA-treated surfaces to anchor [AuCl₄]^- ions. After electrochemical reduction, we observed that it is possible to control the size of the nanoparticles on the surface. Our route opens a new avenue to add versatility to electrochemical interfaces in the field of paper-based electrochemical biosensors.