PCR meets GMR – integrated biosensors for POCT

Magnetic detection in PCR relies on giant magnetoresistive (GMR) sensors whose resistance depends on the magnetic field. Thus, a bound sample that is also bound to a magnetic nanoparticle can be detected magnetically because of the effect of the magnetic nanoparticle on the nearby magnetic field. However, the resistance of GMR sensors also depends on their temperature, posing a unique challenge to the integration of PCR with GMR sensors on a single chip. Here we report accurate control and measurement of temperature in GMR detection for PCR assays and multiplexed DNA biomarker detection for point of care testing (POCT). In particular, GMR biosensors integrated with PCR are extremely promising as a POCT for therapy monitoring of lung cancer management.