Research Seminar Abstract:
Paper has been used as a platform in analytical measurement since the early 1800s but has recently received significant recent attention as a substrate for microfluidic devices.1 Microfluidic paper-based analytical devices (μPADs) are low-cost, can facilitate reagent storage within the fiber network, and can provide fluid transport through capillary action without external pumps. Various μPADs have been reported to date for point-of-care (POC) applications featuring colorimetric and/or electrochemical detection.2 Electrochemical detection for μPADs (ePADs) is an attractive alternative to colorimetric methods due to its high sensitivity and tunable selectivity through choice of the electrode material, electrochemical technique and potential. The first part of my talk will focus on development of a quasi-steady flow on ePAD to enable semi-automation in sample processing similar to conventional flow injection analysis. As a proof of concept, an enzyme kinetics study was conducted with the ePAD using β-galactosidase and p-aminophenyl-galactopyranoside as enzyme and substrate, respectively. Using the proposed ePAD, similar kinetic value (Km, Michaelis-Menten constant) to those reported in literature was successfully obtained.3 The second part of the talk will focus on the incorporation of thermoplastic electrode (TPE) arrays to the flow ePAD to improve sensitivity of the detection. The electrodes were fabricated using graphite and cyclic olefin copolymer using a simple solvent assisted method. Low limit of detection (64 nM ferrocene complex) as well as gain in sensitivity were achieved using this TPE-ePAD.4
(1) Martinez, A. W.; Phillips, S. T.; Butte, M. J.; Whitesides, G. M. Angew. Chemie – Int. Ed. 2007, 46 (8), 1318–1320.
(2) Yang, Y.; Noviana, E.; Nguyen, M. P.; Geiss, B. J.; Dandy, D. S.; Henry, C. S. Anal. Chem. 2017, 89 (1), 71–91.
(3) Adkins, J. A.; Noviana, E.; Henry, C. S. Anal. Chem. 2016, 88 (21), 10639–10647.
(4) Noviana, E.; Klunder, K. J.; Channon, R. B.; Henry, C. S. Anal. Chem. 2019, 91, 2431–2438.