title: Gravity-induced convective flow in microfluidic systems: electrochemical characterization and application to enzyme-linked immunosorbent assay tests.
abstract: A way of using gravity flow to induce a linear convection within a microfluidic system is presented. It is shown and mathematically supported that tilting a 1 cm long covered microchannel is enough to generate flow rates up to 1000 nL.min(-1), which represents a linear velocity of 2.4 mm.s(-1). This paper also presents a method to monitor the microfluidic events occurring in a covered microchannel when a difference of pressure is applied to force a solution to flow in said covered microchannel, thanks to electrodes inserted in the microfluidic device. Gravity-induced flow monitored electrochemically is applied to the performance of a parallel-microchannel enzyme-linked immunosorbent assay (ELISA) of the thyroid-stimulating hormone (TSH) with electrochemical detection. A simple method for generating and monitoring fluid flows is described, which can, for instance, be used for controlling parallel assays in microsystems.
authors.affiliation: DiagnoSwiss SA, Monthey, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Morier
authors.forename: Christine
authors.initials: C
authors.lastname: Vollet
authors.forename: Philippe E
authors.initials: PE
authors.lastname: Michel
authors.forename: Frédéric
authors.initials: F
authors.lastname: Reymond
authors.forename: Joël S
authors.initials: JS
authors.lastname: Rossier
mesh_terms: D004560:Electricity; D004563:Electrochemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D006112:Gravitation; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D044085:Microfluidics; D012212:Rheology; D013972:Thyrotropin / Q000032:analysis
chemical_list: D013972:Thyrotropin