An electrochemical paper-based analytical device with facile carbon fiber-sewed electrodes for highly sensitive detection of hydrogen peroxide in real water

Abstract

A novel and facile method by sewing low-cost fiber electrodes on paper is proposed to fabricate electrochemical paper-based analytical devices (ePADs). Prussian Blue (PB) and Ag/AgCl were deposited on carbon fibers to prepare the working and reference electrodes. The hydrophilic carbon fiber was employed as the counter electrode. All electrodes were sewed on the paper substrate. The linear voltammetry scanning (LSV) and physical characterization results showed that the physico-chemical characteristics of the prepared electrode were maintained after sewing. As a proof of concept, the ePAD fabricating by sewing was used to detect hydrogen peroxide (H2O2). The limit of detection (LOD) achieved 0.9 µM and the ePAD possessed high anti-interference ability to a variety of common ions and biological molecules. Additionally, the robustness of the ePADs against bending (error 6.2 %) manifested that the ePAD had excellent practical applicability. The good reproducibility (3.65 %) displayed by the current responses confirmed that this strategy can be profitably adopted to easily assemble ePADs in a highly flexible manner. In addition, a user-friendly reagent-free ePAD was proposed to determine the content of H2O2 in real water sample without treatment. The good recovery percentage (95.7–99.7 %) demonstrated the high feasibility of the reagent-free ePAD with facile carbon fiber-sewed electrodes in the detection of H2O2 from complex water samples. These results confirm that the sewing method is feasible and promising. This work provides a new insight into fabrication of highly sensitive and highly selective ePADs with fiber electrodes.