Electrochemical Paper‐Based Microfluidics: Harnessing Capillary Flow for Advanced Diagnostics

Abstract

Electrochemical paper‐based microfluidics has attracted much attention due to the promise of transforming point‐of‐care diagnostics by facilitating quantitative analysis with low‐cost and portable analyzers. Such devices harness capillary flow to transport samples and reagents, enabling bioassays to be executed passively. Despite exciting demonstrations of capillary‐driven electrochemical tests, conventional methods for fabricating electrodes on paper impede capillary flow, limit fluidic pathways, and constrain accessible device architectures. This account reviews recent developments in paper‐based electroanalytical devices and offers perspective by revisiting key milestones in lateral flow tests and paper‐based microfluidics engineering. The study highlights the benefits associated with electrochemical sensing and discusses how the detection modality can be leveraged to unlock novel functionalities. Particular focus is given to electrofluidic platforms that embed electrodes into paper for enhanced biosensing applications. Together, these innovations pave the way for diagnostic technologies that offer portability, quantitative analysis, and seamless integration with digital healthcare, all without compromising the simplicity of commercially available rapid diagnostic tests.

Quantitative reagent monitoring in paper-based electrochemical rapid diagnostic tests

“…In this scenario, with a scaling factor of 0.36 ± 0.04 s μL −1 , we were able to quantify the slower flow in comparison to a pristine device, attributed to the increasingly saturated absorbent pad and in accordance with the principles of capillary flow. 34…”