SENSOR AND METHOD FOR MEASURING THE AREAL DENSITY OF MAGNETIC NANOPARTICLES ON A MICRO-ARRAY

摘要

The present invention relates to a method and a device for magnetic detection of binding of biological molecules on a biochip. A magnetoresistive sensor device for measuring an areal density of magnetic nanoparticles on a micro-array, the magnetic nanoparticles (15) being directly or indirectly coupled to the target sample (11), is described. The magnetoresistive sensor device comprises a substrate (3) having attached thereto binding sites (9) able to selectively bind target sample (11), and a magnetoresistive sensor for detecting the magnetic field of the nanoparticles (15) coupled to the target sample. The magnetoresistive sensor comprises a plurality of magnetoresistive sensing elements (17, 19), the width and length dimensions of which are at least a factor 10 or more, preferably a factor 100 or more larger than the diameter of the nanoparticles (15). A corresponding method is described as well.