Magnetoresistance is a change in electrical resistance that depends on magnetic field. The presence of an object of interest (e.g., a magnetic particle) can be sensed by the change in resistance of the MR sensor. Biological assays can be constructed by making magnetic particles bind to MR sensors under biologically specific circumstances. For example, if the MR sensors and magnetic particles are coated with an antigen and a corresponding antibody, respectively or vice versa, then binding of antibody to antigen can be detected via the MR effect.
In biological applications, it is often desired to employ a large array of MR sensors in order to conduct large-scale assays. In such cases, system performance is often limited by electrical noise, and noise mitigation is also of more general interest for all applications of MR sensors. Accordingly, it would be an advance in the art to mitigate noise in MR sensors, especially in connection with arrays of MR sensors.