title: Magnetoelastic immunosensors: amplified mass immunosorbent assay for detection of Escherichia coli O157:H7.
abstract: A mass-sensitive magnetoelastic immunosensor for detection of Escherichia coli O157:H7 is described, based on immobilization of affinity-purified antibodies attached to the surface of a micrometer-scale magnetoelastic cantilever. Alkaline phosphatase is used as a labeled enzyme to the anti-E. coli O157:H7 antibody, amplifying the mass change associated with the antibody-antigen binding reaction by biocatalytic precipitation of 5-bromo-4-chloro-3-indolyl phosphate in a pH 10.0 PBS solution. The detection limit of the biosensor is 10(2) E. coli O157:H7 cells/mL. A linear change in the resonance frequency of the biosensor was found to E. coli O157:H7 concentrations ranging from 10(2) to 10(6) cells/mL.
authors.affiliation: Department of Electrical Engineering, 217 Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 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: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D007163:Immunosorbent Techniques / Q000295:instrumentation; D008280:Magnetics / Q000295:instrumentation*