title: A staphylococcal enterotoxin B magnetoelastic immunosensor.
abstract: A magnetoelastic immunosensor for detection of staphylococcal enterotoxin B (SEB) is described. The magnetoelastic sensor is a newly developed mass/elasticity-based transducer of high sensitivity having a material cost of approximately $0.001/sensor. Affinity-purified rabbit anti-SEB antibody was covalently immobilized on magnetoelastic sensors, of dimensions 6 mm x 2 mm x 28 microm. The affinity reaction of biotin-avidin and biocatalytic precipitation are used to amplify antigen-antibody binding events on the sensor surface. Horseradish peroxidase (HRP) and alkaline phosphatase were examined as the labeled enzymes to induce biocatalytic precipitation. The alkaline phosphatase substrate, 5-bromo-4-chloro-3-indolyl phosphate (BCIP) produces a dimer, which binds tightly to the sensor surface, inducing a change in sensor resonance frequency. The biosensor demonstrates a linear shift in resonance frequency with staphylococcal enterotoxin B concentration between 0.5 and 5 ng/ml, with a detection limit of 0.5 ng/ml.
authors.affiliation: Department of Electrical Engineering, 217 Materials Research Laboratory, The Pennsylvania State University, University Park, 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: D000469:Alkaline Phosphatase / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004548:Elasticity; D004768:Enterotoxins / Q000032:analysis* / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation* / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000737:chemistry*; D008280:Magnetics / Q000295:instrumentation*
chemical_list: D020099:Coated Materials, Biocompatible; D004768:Enterotoxins; D004800:Enzymes, Immobilized; C031818:enterotoxin B, staphylococcal; D006735:Horseradish Peroxidase; D000469:Alkaline Phosphatase