title: Polyelectrolyte microshells as carriers for fluorescent sensors: loading and sensing properties of a ruthenium-based oxygen indicator.
abstract: A strategy for the design and fabrication of microcapsule-based fluorescent biosensors containing indicators and internal references is described. The rationale for this work is the physical immobilization and chemical separation of assay chemistry for use in biological environments. Using the general approach of depositing oppositely charged species on colloidal micro/nanotemplates, a sensor system employing polyelectrolyte microshells for uptake of functional molecules is proposed, and experiments to demonstrate the feasibility of nanoengineering the sensor properties are described in the context of an oxygen sensor. Methods for immobilization and entrapment of fluorescent indicator and reference dyes are shown, along with the pH dependence of this process. Embedded dyes are shown to be stable and retain their function, as demonstrated with oxygen-sensitivity experiments of loaded microcapsules. Although oxygen sensitivity is presented as an example of a specific application, the overall strategy is likely more generally useful. The work suggests that polyelectrolyte microshells may be used as a platform to develop novel sensors by entrapment of functional materials.
authors.affiliation: Biomedical Engineering Program, Institute for Micromanufacturing, Louisiana Tech University, Ruston, Louisiana, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McShane
authors.forename: J Quincy
authors.initials: JQ
authors.lastname: Brown
authors.forename: Kyle B
authors.initials: KB
authors.lastname: Guice
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Lvov
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry; D004867:Equipment Design; D005456:Fluorescent Dyes; D008863:Microspheres; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D009942:Organometallic Compounds / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D020099:Coated Materials, Biocompatible; D004573:Electrolytes; D005456:Fluorescent Dyes; D009942:Organometallic Compounds; D011108:Polymers; C415768:tris(2,2'-bipyridyl)ruthenium(II); D010100:Oxygen