title: Microfabricated glucose biosensor for culture well operation.
abstract: A water-based carbon screen-printing ink formulation, containing the redox mediator cobalt phthalocyanine (CoPC) and the enzyme glucose oxidase (GOx), was investigated for its suitability to fabricate glucose microbiosensors in a 96-well microplate format: (1) the biosensor ink was dip-coated onto a platinum (Pt) wire electrode, leading to satisfactory amperometric performance; (2) the ink was deposited onto the surface of a series of Pt microelectrodes (10-500 μm diameter) fabricated on a silicon substrate using MEMS (microelectromechanical systems) microfabrication techniques: capillary deposition proved to be successful; a Pt microdisc electrode of ≥100 μm was required for optimum biosensor performance; (3) MEMS processing was used to fabricate suitably sized metal (Pt) tracks and pads onto a silicon 96 well format base chip, and the glucose biosensor ink was screen-printed onto these pads to create glucose microbiosensors. When formed into microwells, using a 340 μl volume of buffer, the microbiosensors produced steady-state amperometric responses which showed linearity up to 5 mM glucose (CV=6% for n=5 biosensors). When coated, using an optimised protocol, with collagen in order to aid cell adhesion, the biosensors continued to show satisfactory performance in culture medium (linear range to 2 mM, dynamic range to 7 mM, CV=5.7% for n=4 biosensors). Finally, the operation of these collagen-coated microbiosensors, in 5-well 96-well format microwells, was tested using a 5-channel multipotentiostat. A relationship between amperometric response due to glucose, and cell number in the microwells, was observed. These results indicate that microphotolithography and screen-printing techniques can be combined successfully to produce microbiosensors capable of monitoring glucose metabolism in 96 well format cell cultures. The potential application areas for these microbiosensors are discussed.
authors.affiliation: Centre for Research in Biosciences, Faculty of Health and Life Sciences, University of the West of England, Bristol, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Pemberton
authors.forename: T
authors.initials: T
authors.lastname: Cox
authors.forename: R
authors.initials: R
authors.lastname: Tuffin
authors.forename: I
authors.initials: I
authors.lastname: Sage
authors.forename: G A
authors.initials: GA
authors.lastname: Drago
authors.forename: N
authors.initials: N
authors.lastname: Biddle
authors.forename: J
authors.initials: J
authors.lastname: Griffiths
authors.forename: R
authors.initials: R
authors.lastname: Pittson
authors.forename: G
authors.initials: G
authors.lastname: Johnson
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.forename: S K
authors.initials: SK
authors.lastname: Jackson
authors.forename: G
authors.initials: G
authors.lastname: Kenna
authors.forename: R
authors.initials: R
authors.lastname: Luxton
authors.forename: J P
authors.initials: JP
authors.lastname: Hart
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D018929:Cell Culture Techniques; D002460:Cell Line; D004563:Electrochemistry / Q000379:methods; D005947:Glucose / Q000737:chemistry / Q000302:isolation & purification*; D005949:Glucose Oxidase / Q000737:chemistry; D007211:Indoles / Q000737:chemistry; D008839:Microelectrodes; D055616:Microtechnology / Q000379:methods*; D009942:Organometallic Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D014867:Water; C063633:cobalt phthalocyanine; D005949:Glucose Oxidase; D005947:Glucose