title: Encapsulation of glucose oxidase and an oxygen-quenched fluorophore in polyelectrolyte-coated calcium alginate microspheres as optical glucose sensor systems.
abstract: Microspheres coated with polyelectrolyte multilayers (PEM's) are being investigated for potential use as implantable biosensors-so-called "smart tattoos." In this work, the feasibility of this approach for glucose sensors was demonstrated by glucose oxidase encapsulated within calcium alginate microspheres, followed by entrapment of an oxygen-quenched ruthenium compound in the same microstructure. A novel feature of these microdevices is the formation of multilayer nanofilms on the surface of the microspheres, used to stabilize enzyme entrapment and control substrate diffusion. Confocal microscopy was used to confirm the stable encapsulation of sensor chemistry. The reversible response of sensors to step changes in glucose was observed, and preliminary experimental data were compared to theoretical predictions produced by a computational model. These findings demonstrate the promise of the described nanoengineering approach for production of functional implantable glucose sensor materials.
authors.affiliation: Biomedical Engineering Program and the Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Ave., P.O. Box 10137, Ruston, LA 71272, USA.
authors.forename: J Quincy
authors.initials: JQ
authors.lastname: Brown
authors.forename: Rohit
authors.initials: R
authors.lastname: Srivastava
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McShane
mesh_terms: D000464:Alginates; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D005456:Fluorescent Dyes; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D018613:Microscopy, Confocal; D008863:Microspheres; D011073:Polyamines; D013050:Spectrometry, Fluorescence
chemical_list: D000464:Alginates; D005456:Fluorescent Dyes; D006603:Hexuronic Acids; D011073:Polyamines; C063994:polyallylamine; D020723:Glucuronic Acid; D005949:Glucose Oxidase; D005947:Glucose