Sensor and method for measuring the areal density of magnetic nanoparticles on a micro-array

The invention relates to are used in biology molecule's with the magnetic detection method and device of bio-chip. Described for measuring the microarray magnetic particle detecting surface density a magnetic sensor device, the magnetic particle (15) or the indirect to the target sample (11). The magnetic resistance sensor device comprises a substrate (3), the substrate (3) is attached to the anti-attachment rod can selectively a combination target sample (11) binding site (9), and a measuring to the target sample particle (15) magnetic field a magnetic sensor. The magnetic resistance sensor comprises several magnetic resistance sensors (17,19), wherein width and size of particle (15) 10 times or is at least one multiple, preferably 100 times or more than. With is made drawing on the corresponding method.