title: A magnetoelastic bioaffinity-based sensor for avidin.
abstract: A magnetoelastic bioaffinity sensor coupled with biocatalytic precipitation is described for avidin detection. The non-specific adsorption characteristics of streptavidin on different functionalized sensor surfaces are examined. It is found that a biotinylated poly(ethylene glycol) (PEG) interface can effectively block non-specific adsorption of proteins. Coupled with the PEG immobilized sensor surface, alkaline phosphatase (AP) labeled streptavidin is used to track specific binding on the sensor. This mass-change-based signal is amplified by the accumulation on the sensor of insoluble products of 5-bromo-4-chloro-3-indolyl phosphate catalyzed by AP. The resulting mass loading on the sensor surface in turn shifts the resonance frequency of the magnetoelastic sensors, with an avidin detection limit of approximately 200 ng/ml.
authors.affiliation: Department of Electrical Engineering, 217 Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania, PA 16802, USA.
authors.forename: Chuanmin
authors.initials: C
authors.lastname: Ruan
authors.forename: Kefeng
authors.initials: K
authors.lastname: Zeng
authors.forename: Oomman K
authors.initials: OK
authors.lastname: Varghese
authors.forename: Craig A
authors.initials: CA
authors.lastname: Grimes
mesh_terms: D001360:Avidin / Q000032:analysis* / Q000276:immunology*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D008280:Magnetics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000276:immunology*; D014159:Transducers
chemical_list: D001360:Avidin; D019809:Streptavidin