Abstract: A system includes an apparatus having at least one permanent magnet and at least one magnetic field sensor at a pole of the at least one permanent magnet and configured to be positioned relative to a surface of a membrane containing immobilized magnetic particles selectively bound to an analyte such that the magnetic particles are magnetized by the at least one permanent magnet. The system further includes a stage configured to move at least one of the apparatus and the membrane relative to one another with an oscillatory movement parallel to the surface of the membrane, at least one controller configured to control the oscillatory movement, and a data acquisition unit configured to receive signals from the at least one magnetic field sensor and the at least one controller method.

Abstract: A method, system, and apparatus for the rapid detection of analyte(s) of interest are disclosed which can provide high sensitivity quantification of the analyte concentration in a lateral follow assay. The method includes labeling detection molecules with magnetic particles and immobilizing the magnetic particles on a nitrocellulose membrane upon specific biochemical recognition and binding. An external magnetic field is applied to the magnetic particles to induce magnetic induction, and a magnetoresistance sensor is positioned close to the membrane and magnetic particles. A periodic signal in the sensor is produced when a mechanical oscillatory movement is provided to the membrane relative to the sensor (or vice versa). Triggered time averaging of signals in synchronization with the oscillatory motion enables noise reduction of less than 30 dB and significant improvement of assay sensitivity.