Bionic Magnetic Sensor Based on the MagR/Cry4 Complex-Configured Graphene Transistor with an Integrated On-Chip Gate.

Magnetic-sensitive proteins are regarded as key factors in animals' precise perception of the geomagnetic field. Accurate feedback on the response of these tiny proteins to magnetic fields remains a challenge. Here, we first propose a real-time accurate magnetic sensor based on the MagR/Cry4 complex-configured graphene transistor with an integrated on-chip gate. A nanometer-thick denatured bovine serum albumin film was used as the bio-interface of graphene electrolyte-gated transistors (EGTs) to immobilize the MagR/Cry4 complex. With the optimization and characterization of this bionic graphene EGT, it could detect magnetic fields in real time with a sensitivity of 1 mT, which is far lower than in earlier research. It was concluded that our MagR/Cry4 complex-configured graphene EGTs with a side-gate held great promise in terms of geomagnetic field detection. Furthermore, the constructed approach in this paper could also be utilized as a general solution for recording the response of magnetically sensitive biomolecules to magnetic fields in real time.