Fluidic Automation of Nitrate and Nitrite Bioassays in Whole Blood by Dissolvable-Film Based Centrifugo-Pneumatic Actuation

Abstract

This paper demonstrates the full centrifugal microfluidic integration and automation of all liquid handling steps of a 7-step fluorescence-linked immunosorbent assay (FLISA) for quantifying nitrate and nitrite levels in whole blood within about 15 min. The assay protocol encompasses the extraction of metered plasma, the controlled release of sample and reagents (enzymes, co-factors and fluorescent labels), and incubation and detection steps. Flow control is implemented by a rotationally actuated dissolvable film (DF) valving scheme. In the valves, the burst pressure is primarily determined by the radial position, geometry and volume of the valve chamber and its inlet channel and can thus be individually tuned over an extraordinarily wide range of equivalent spin rates between 1,000 RPM and 5,500 RPM. Furthermore, the vapour barrier properties of the DF valves are investigated in this paper in order to further show the potential for commercially relevant on-board storage of liquid reagents during shelf-life of bioanalytical, ready-to-use discs.

An enzyme-free glucose sensor based on a difunctional diboronic acid for molecular recognition and potentiometric transduction

“…30,31 As illustrated in Fig. S4, † although small potential changes can be induced aer additions of these ions, they would not interfere with the glucose detection.…”

Biosensing enhancement of dengue virus using microballoon mixers on centrifugal microfluidic platforms

“…Nevertheless, by means of the same air chamber the mixer could pump the mixed liquids against the centrifugal force to other reservoirs and therefore enable more complex bioassays on the disk (Noroozi et al, 2009(Noroozi et al, , 2011. The mixing techniques on centrifugal microfluidics discussed here are useful approaches that have been employed, for example, in quantifying nitrate and nitrite levels in blood, reparatory virus detection, detection of the antibiotic resistance gene mecA of Staphylococcus aureus and several enzyme linked immunosorbent assays (ELISA) Kim et al, 2013;Kinahan et al, 2014;Lee et al, 2011;Lutz et al, 2010;Noroozi et al, 2009Noroozi et al, , 2011Nwankire et al, 2013Nwankire et al, , 2014Siegrist et al, 2010Siegrist et al, , 2006.…”

Phase-selective graphene oxide membranes for advanced microfluidic flow control

“…Nwankire et al 17,18 built on this system by integrating and automating multistep bioassay protocols actuated by the dissolvable-film-based centrifugopneumatic valving scheme. Kinahan et al advanced this sacrificial technology to an event-triggered valving paradigm that enables the more dynamic control of fluids on a centrifugal microfluidic platform 19,20 .…”