title: Magnetic micro/nanoparticle flocculation-based signal amplification for biosensing.
abstract: We report a time and cost efficient signal amplification method for biosensors employing magnetic particles. In this method, magnetic particles in an applied external magnetic field form magnetic dipoles, interact with each other, and accumulate along the magnetic field lines. This magnetic interaction does not need any biomolecular coating for binding and can be controlled with the strength of the applied magnetic field. The accumulation can be used to amplify the corresponding pixel area that is obtained from an image of a single magnetic particle. An application of the method to the Escherichia coli 0157:H7 bacteria samples is demonstrated in order to show the potential of the approach. A minimum of threefold to a maximum of 60-fold amplification is reached from a single bacteria cell under a magnetic field of 20 mT.
authors.affiliation: BioMINDS (Bio Micro/Nano Devices and Sensors) Laboratory, Department of Electrical and Electronics Engineering, Abdullah Gül University, Kayseri, Turkey.
authors.forename: Omary
authors.initials: O
authors.lastname: Mzava
authors.affiliation: BioMINDS (Bio Micro/Nano Devices and Sensors) Laboratory, Department of Electrical and Electronics Engineering, Abdullah Gül University, Kayseri, Turkey.
authors.forename: Zehra
authors.initials: Z
authors.lastname: Taş
authors.affiliation: BioMINDS (Bio Micro/Nano Devices and Sensors) Laboratory, Department of Electrical and Electronics Engineering, Abdullah Gül University, Kayseri, Turkey; Bioengineering Department, Abdullah Gül University, Kayseri, Turkey.
authors.forename: Kutay
authors.initials: K
authors.lastname: İçöz
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D019453:Escherichia coli O157 / Q000378:metabolism; D005427:Flocculation; D007501:Iron / Q000032:analysis; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008863:Microspheres; D061848:Optical Imaging; D010316:Particle Size; D012815:Signal Processing, Computer-Assisted
chemical_list: D058185:Magnetite Nanoparticles; D007501:Iron
keywords: image-based detection; magnetic dipole–dipole interaction; magnetic micro/nanoparticle accumulation; signal amplification