title: Detection of Staphylococcus aureus enterotoxin B at femtomolar levels with a miniature integrated two-channel surface plasmon resonance (SPR) sensor.
abstract: Surface plasmon resonance (SPR) biosensors offer the capability for continuous real-time monitoring. The commercial instruments available have been large in size, expensive, and not amenable to field applications. We report here an SPR sensor system based on a prototype two-channel system similar to the single channel Spreeta devices. This system is an ideal candidate for field use. The two-channel design provides a reference channel to compensate for bulk refractive index (RI), non-specific binding and temperature variations. The SPR software includes a calibration function that normalizes the response from both channels, thus enabling accurate referencing. In addition, a temperature-controlled enclosure utilizing a thermo-electric module based on the Peltier effect provides the temperature stability necessary for accurate measurements of RI. The complete SPR sensor system can be powered by a 12V battery. Pre-functionalized, disposable, gold-coated thin glass slides provide easily renewable sensor elements for the system. Staphylococcus aureus enterotoxin B (SEB), a small protein toxin was directly detectable at sub-nanomolar levels and with amplification at femtomolar levels. A regeneration procedure for the sensor surface allowed for over 60 direct detection cycles in a 1-month period.
authors.affiliation: Department of Medicine, University of Washington, Seattle, WA 98195. USA.
authors.forename: Alexei N
authors.initials: AN
authors.lastname: Naimushin
authors.forename: Scott D
authors.initials: SD
authors.lastname: Soelberg
authors.forename: Di K
authors.initials: DK
authors.lastname: Nguyen
authors.forename: Lucinda
authors.initials: L
authors.lastname: Dunlap
authors.forename: Dwight
authors.initials: D
authors.lastname: Bartholomew
authors.forename: Jerry
authors.initials: J
authors.lastname: Elkind
authors.forename: Jose
authors.initials: J
authors.lastname: Melendez
authors.forename: Clement E
authors.initials: CE
authors.lastname: Furlong
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004768:Enterotoxins / Q000032:analysis* / Q000276:immunology; D004867:Equipment Design; D005898:Glass / Q000737:chemistry; D006041:Goats; D006046:Gold / Q000737:chemistry; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D008832:Microchemistry; D008892:Milk / Q000737:chemistry; D008904:Miniaturization; D008962:Models, Theoretical; D011817:Rabbits; D012623:Seawater / Q000737:chemistry; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D014556:Urine / Q000737:chemistry
chemical_list: D020099:Coated Materials, Biocompatible; D004768:Enterotoxins; C031818:enterotoxin B, staphylococcal; D006046:Gold