Investigation of Electrical Conductance in Immobilized Zebrafish Cryptochrome (zfCRY4) Protein*

In the past decades, several studies have shown that many animals, especially migratory birds, have an ability to detect and utilize the Earth’s magnetic field information to navigate their way during migration. A magnetic sensing mechanism is believed to be located in the bird's eyes which relies on protein cryptochrome proteins (CRYs). This protein belongs to a class of flavoproteins and is sensitive to blue light. The signaling state of cryptochrome is controlled by the oxidation state of flavin adenine dinucleotide (FAD), which can be activated via a coherent photoreduction process. Furthermore, the behavior of electron hopping in the FAD cofactor is theoretically known to depend on the presence of an external magnetic field. Immobilized zebrafish (Danio rerio) cryptochrome 4 (zfCRY4) protein on an ultra-flat gold thin film was studied to investigate the potential implementation in future devices. Results will be presented on the electrical conductance of a single protein thin film measured with conductive atomic force microscopy (C-AFM) as a function of tip force and blue light illumination.