title: Acoustic wave immunosensing of a meningococcal antigen using gold nanoparticle-enhanced mass sensitivity.
abstract: Bacterial meningitis is an infection of the thin membranes covering the brain and spinal cord by a number of microorganisms including Neisseria meningitidis, which can lead to permanent neurological damage in the event of late diagnosis. Given the quick onset and severity of the disease, there is a clear need for a rapid, sensitive and specific diagnostic technique. Here, we describe the development and evaluation of an acoustic wave sensor, the quartz crystal microbalance (QCM), as a rapid immunosensor employing antibodies against the cell surface outer membrane protein 85 (OMP85) of N. meningitidis as an immobilized selective layer. These antibodies were directionally orientated as receptors by thin film deposition of structured polyvinylidene fluoride and Protein A. The sensitivity of this QCM immunosensor was further increased by conjugation of the OMP85 antigen to 50 nm gold nanoparticles providing reproducible detection of the target down to 300 ng/mL. Subsequent treatment of the QCM surface with an acidic glycine solution regenerated the immunosensor allowing each crystal to be used several times.
authors: School of Applied Sciences, Royal Melbourne Institute of Technology, Melbourne 3001, Australia.
authors: Sreenivasulu B
authors: SB
authors: Reddy
authors: David E
authors: DE
authors: Mainwaring
authors: Mohammad Al
authors: MA
authors: Kobaisi
authors: Panlop
authors: P
authors: Zeephongsekul
authors: John V
authors: JV
authors: Fecondo
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000942:Antigens, Bacterial / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation; D009345:Neisseria meningitidis / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000942:Antigens, Bacterial; D006046:Gold