Electrically-Actuated Valves for Woven Fabric Lateral Flow Devices.
The integration of flow control elements into low-cost biosensors presents a significant engineering challenge. This Article describes the development and integration of active, chemical valves into lateral flow devices, using a scalable, single-step, weaving-based manufacturing approach. The valve was constructed from an electrically conductive polymer, polypyrrole. The polymer switches between wetting and nonwetting states when it is reduced and oxidized via the application of an electrochemical potential. In this work, yarns were first coated with polypyrrole and integrated into fabric lateral flow sensors. The coated yarns were stimulated in situ via integrated electrodes. Coated textiles were characterized for their response to variations in the applied electrical potential, the duration for which the potential is applied, and the chemical composition of the polymer. Among these tuning parameters, the concentration of iron (iii) chloride utilized to catalyze the synthesis of the polymer, was found to be a significant determinant in the wetting range of the polymer. Complete ON/OFF flow control was achieved at applied potentials of 20 V.cm-1, within 120 s of stimulation, using 0.1 M iron (iii) chloride, making the valve fairly easy to incorporate into point-of-care format. The practical utility of the valve was demonstrated by performing a Lowry protein assay in the device, wherein fluid flow was deactivated to allow individual reaction steps to go to completion prior to reactivation. Significant improvements in the sensitivity and linear range of the devices are reported in a simple straight-channel, lateral flow device, with the potential to develop more complex channel geometries via the weaving-based approach.
Department of Chemical Engineering, Northeastern University , 360 Huntington Avenue, 313 Snell Engineering Center, Boston, Massachusetts 02115, United States.
Tanya
0000-0001-8112-7991
T
Narahari
Achira Labs Private Limited , 66B, 13th Cross Road, 2nd Main Road, J.P Nagar Phase III, Bangalore 560078, Karnataka, India.
Dhananjaya
D
Dendukuri
Department of Chemical Engineering, Northeastern University , 360 Huntington Avenue, 313 Snell Engineering Center, Boston, Massachusetts 02115, United States.|Barnett Institute of Chemical and Biological Analysis, Northeastern University , Boston, Massachusetts 02115, United States.
Shashi K
SK
Murthy
D015374:Biosensing Techniques; D002712:Chlorides / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005290:Ferric Compounds / Q000737:chemistry; D019095:Point-of-Care Systems; D011108:Polymers / Q000737:chemistry; D011506:Proteins / Q000032:analysis; D011758:Pyrroles / Q000737:chemistry
D002712:Chlorides; D005290:Ferric Compounds; D011108:Polymers; D011506:Proteins; D011758:Pyrroles; C067635:polypyrrole; C024555:ferric chloride