title: An electrochemical-sensor system for real-time flow measurements in porous materials.
abstract: Flow monitoring in porous materials is critical for the engineering of paper-based microfluidic bioassays. Here, we present an electrochemical-sensor system that monitors the liquid flow in porous materials without affecting the real flow in paper-strip samples. The developed microfluidic sensor records an amperometric signal created by the solution movement mediated by paper wicking. This approach allows the in situ monitoring of the different hydrodynamic conditions of a specific paper geometry or composition. In addition, the method proposed in this work was employed to characterise the fluid flow of different nitrocellulose paper strips after oxygen-plasma treatment or dextran coating. The dextran fluid-flow modifiers were further used on the paper strip-based assays as means of signal enhancement. The proposed electrochemical-sensing method offers a valuable alternative to existing optical-based monitoring techniques for flow measurement in paper-based microfluidic systems.
authors: Department of Biomedical Engineering, School of Life Sciences, Ulsan National, Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea; Department of Biomedical Engineering, College of Engineering, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI 2350, USA.
authors: Cédric
authors: C
authors: Bathany
authors: Department of Biomedical Engineering, School of Life Sciences, Ulsan National, Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea.
authors: Ja-Ryoung
authors: JR
authors: Han
authors: Department of Biomedical Engineering, School of Life Sciences, Ulsan National, Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea.
authors: Kameel
authors: K
authors: Abi-Samra
authors: Department of Biomedical Engineering, School of Life Sciences, Ulsan National, Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea; Department of Biomedical Engineering, College of Engineering, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI 2350, USA.
authors: Shuichi
authors: S
authors: Takayama
authors: Department of Biomedical Engineering, School of Life Sciences, Ulsan National, Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea; Center for Soft and Living Matter, Institute for Basic Science (IBS), UNIST-gil 50, Ulsan 689-798, Republic of Korea. Electronic address: ykcho@unist.ac.kr.
authors: Yoon-Kyoung
authors: YK
authors: Cho
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003199:Computer Systems; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D056656:Lab-On-A-Chip Devices; D010209:Paper; D016062:Porosity; D015203:Reproducibility of Results; D012212:Rheology / Q000295:instrumentation*; D012680:Sensitivity and Specificity
keywords: Amperometric detection; Electrochemical detection; Fluid-flow modifiers; Immunochromatographic assay; Paper-based microfluidics