title: Magnetic modulation biosensing for rapid and homogeneous detection of biological targets at low concentrations.
abstract: This paper reviews the development of a magnetic modulation biosensing (MMB) system for rapid, simple and sensitive detection of biological targets in homogeneous solution at low concentrations. It relies on condensation and modulation of the fluorescent-labeled probes attached to magnetic beads using an alternating magnetic field gradient. Condensation of the beads from the entire volume increases the signal while modulation separates the signal from the background noise of the non-magnetized solution. We first discuss the motivation and challenges in specific DNA sequences detection as well as current approaches to overcome some of these challenges. We then present the MMB system, DNA detection schemes and magnetic beads manipulation in solution. Rapid detection at sub-picomolar concentrations of fluorescent-labeled probes as well as of coding sequences of the non-structural Ibaraki virus protein 3 (NS3) complementary DNA (cDNA) without any washing or separation step is also reviewed. Finally, we show preliminary results of protein detection using a 'sandwich'-based assay.
authors.affiliation: Department of Physical Electronics, Faculty of Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel. amosd@post.tau.ac.il
authors.forename: Amos
authors.initials: A
authors.lastname: Danielli
authors.forename: Noga
authors.initials: N
authors.lastname: Porat
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ehrlich
authors.forename: Ady
authors.initials: A
authors.lastname: Arie
mesh_terms: D001704:Biopolymers / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D052203:Ferrosoferric Oxide / Q000008:administration & dosage / Q000737:chemistry*; D018189:Immunomagnetic Separation / Q000295:instrumentation; D008163:Luminescent Measurements / Q000295:instrumentation*; D008280:Magnetics / Q000295:instrumentation*; D008832:Microchemistry / Q000295:instrumentation*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
chemical_list: D001704:Biopolymers; D052203:Ferrosoferric Oxide