ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Construction and characterization of sandwich-type laccase electrode based on functionalized conducting polymers

Feifan Wang, Xinxin Yu, and Guangtao Zhao

Department of Immunology, School of Basic Medicine, Binzhou Medical University, Yantai, China

E-mail: gtzhao@bzmc.edu.cn

Received: 15 May 2020  Accepted: 27 August 2020

Abstract:

Laccase (Lac) is a multi-active-center glycoprotein. Its heterogeneous electron transfer efficiency depends on the distance between the substrate binding site and the electrode surface. Laccase encapsulation by conducting polymers should be favorable for the direct electron transfer (DET) process, thus improving the electrocatalytic efficiency of the laccase electrode. Here, a sandwich-type laccase electrode based on functionalized conducting polymers was developed. First, porous poly (3-aminophenylboronic acid) (PAPBA) conductive film was electrodeposited on a glassy carbon electrode (GCE), and on which laccase was then immobilized via the specific binding of the boronic acid group from PAPBA and the glycosyl group on laccase. In addition to higher laccase loading, the present Lac/PAPBA/GCE electrode is more robust than that prepared by physical adsorption of laccase on conducting polymer. For laccase to be wired better, a poly (3,4-ethylenedioxythiophene) (PEDOT) conductive film with polystyrenesulfonate anion (PSS⁻) as dopant was electrochemically covered on the Lac/PAPBA/GCE. In addition to the compatibility among the stability of the cyclic boronic acid ester, the biological activity of the laccase, and the polymer conductivity, the sandwich-type laccase electrode was demonstrated to be more efficient than the counterpart without the second layer for the electroreduction of O₂ probably due to a so-called “cage effect”.

Graphic abstract

The "cage effect" of the sandwich-type conducting polymers reduces the requirement for laccase orientation and greatly improves the electrocatalytic performance of the laccase electrode.

Keywords: Functionalized conducting polymer; Laccase electrode; Direct electron transfer; Electrocatalysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01336-6

Chemical Papers 75 (2) 725–733 (2021)