title: At-line bioprocess monitoring by immunoassay with rotationally controlled serial siphoning and integrated supercritical angle fluorescence optics.
abstract: In this paper we report a centrifugal microfluidic "lab-on-a-disc" system for at-line monitoring of human immunoglobulin G (hIgG) in a typical bioprocess environment. The novelty of this device is the combination of a heterogeneous sandwich immunoassay on a serial siphon-enabled microfluidic disc with automated sequential reagent delivery and surface-confined supercritical angle fluorescence (SAF)-based detection. The device, which is compact, easy-to-use and inexpensive, enables rapid detection of hIgG from a bioprocess sample. This was achieved with, an injection moulded SAF lens that was functionalized with aminopropyltriethoxysilane (APTES) using plasma enhanced chemical vapour deposition (PECVD) for the immobilization of protein A, and a hybrid integration with a microfluidic disc substrate. Advanced flow control, including the time-sequenced release of on-board liquid reagents, was implemented by serial siphoning with ancillary capillary stops. The concentration of surfactant in each assay reagent was optimized to ensure proper functioning of the siphon-based flow control. The entire automated microfluidic assay process is completed in less than 30 min. The developed prototype system was used to accurately measure industrial bioprocess samples that contained 10 mg mL(-1) of hIgG.
authors.affiliation: Biomedical Diagnostics Institute, National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin 9, Ireland. charles.nwankire@dcu.ie
authors.forename: Charles E
authors.initials: CE
authors.lastname: Nwankire
authors.forename: Gerard G
authors.initials: GG
authors.lastname: Donohoe
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Jonathan
authors.initials: J
authors.lastname: Siegrist
authors.forename: Martin
authors.initials: M
authors.lastname: Somers
authors.forename: Dirk
authors.initials: D
authors.lastname: Kurzbuch
authors.forename: Ruairi
authors.initials: R
authors.lastname: Monaghan
authors.forename: Maria
authors.initials: M
authors.lastname: Kitsara
authors.forename: Robert
authors.initials: R
authors.lastname: Burger
authors.forename: Stephen
authors.initials: S
authors.lastname: Hearty
authors.forename: Julie
authors.initials: J
authors.lastname: Murrell
authors.forename: Christopher
authors.initials: C
authors.lastname: Martin
authors.forename: Martha
authors.initials: M
authors.lastname: Rook
authors.forename: Louise
authors.initials: L
authors.lastname: Barrett
authors.forename: Stephen
authors.initials: S
authors.lastname: Daniels
authors.forename: Colette
authors.initials: C
authors.lastname: McDonagh
authors.forename: Richard
authors.initials: R
authors.lastname: O'Kennedy
authors.forename: Jens
authors.initials: J
authors.lastname: Ducrée
mesh_terms: D002138:Calibration; D002498:Centrifugation / Q000295:instrumentation; D004867:Equipment Design; D005453:Fluorescence; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis*; D055617:Micro-Electrical-Mechanical Systems; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D055095:Optics and Photonics / Q000295:instrumentation; D011437:Propylamines; D012821:Silanes / Q000737:chemistry
chemical_list: D007074:Immunoglobulin G; D011437:Propylamines; D012821:Silanes; C477625:amino-propyl-triethoxysilane