Toward scalable fabrication of electrochemical paper sensor without surface functionalization

Hao Ling,Zhiling Zhao,Cheng Wang,Xiaohui Wang,Rui Wu,Gregory F Payne,Xiaowen Shi,Wenjia Han

doi:10.1038/s41528-022-00143-1

Abstract

Paper-based electrochemical sensors provide the opportunity for low-cost, portable and environmentally friendly single-use chemical analysis and there are various reports of surface-functionalized paper electrodes. Here we report a composite paper electrode that is fabricated through designed papermaking using cellulose, carbon fibers (CF), and graphene oxide (GO). The composite paper has well-controlled structure, stable, and repeatable properties, and offers the electrocatalytic activities for sensitive and selective chemical detection. We demonstrate that this CF/GO/cellulose composite paper can be reduced electrochemically using relatively mild conditions and this GO reduction confers electrocatalytic properties to the composite paper. Finally, we demonstrate that this composite paper offers sensing performance (sensitivity and selectivity) comparable to, or better than, paper-based sensors prepared by small-batch surface-modification (e.g., printing) methods. We envision this coupling of industrialized papermaking technologies with interfacial engineering and electrochemical reduction can provide a platform for single-use and portable chemical detection for a wide range of applications.

Highlights

Cellulose-based paper has attracted considerable attention as a matrix for portable single-use electrochemical sensing because of its low cost, lightweight, and biodegradability[1,2,3,4,5,6,7]
A critical requirement for using papermaking technology to prepare stable and uniform composite paper with repeatable properties, is that the cellulose, carbon fibers (CF), and graphene oxide (GO) must be uniformly dispersed in water to make pulp (Fig. 2a)
The resulting CF/GO/cellulose “pulp” could be processed into composite paper and a very fast processing time is confirmed

Summary

Introduction

Cellulose-based paper has attracted considerable attention as a matrix for portable single-use electrochemical sensing because of its low cost, lightweight, and biodegradability[1,2,3,4,5,6,7]. Typical routes for generating paper-based electrochemical sensors use post functionalization methods (e.g., printing) to deposit components that confer conductivity and electrocatalytic activity onto the surface of the paper substrate[8,9,10,11,12,13] These studies have demonstrated impressive performance attributes and suggest an exciting vision forward, a key requirement toward the widespread adoption of paper-based electrochemical sensors will be the scalable fabrication of stable, low-cost paper-based electrodes with repeatable properties, which still remains a challenge. Taking screen printing as an example, many factors, including the viscosity and solid content of printing ink, printing strength, and the structure of paper substrate, all affect the sensitivity of paper-based sensor leading to great uncertainty in repeatability These challenges can hardly be resolved, unless standard paper electrode with well-controlled structure and imbed functionality can be scalably produced and directly used needing no surface treatment. It is difficult to integrate functional materials with paper into defined structure and area in mass production because of the lack of bonding and interaction between cellulose fibers and functional materials

Methods

Results

Conclusion