High Response Photodetection by Applying the Optimized Photoreceptor Protein Modification on Graphene Based Field Effect Transistors

In this work, we combined photoreceptor protein with graphene based field effect transistors to achieve a high responsivity photodetector. Three different aromatic hydrocarbons were used to functionalize graphene with carboxyl groups via pi-pi stacking interactions, and 1-pyrenebutyric acid exhibited the best result for photoreceptor protein immobilization. Besides, the modification procedure of photoreceptor protein was also optimized by using a novel protein stack way on the device. Unlike conventional self-assembly method, photoreceptor proteins were cross-linked before immobilized on graphene thin film and yielded a higher modification density. Finally, the photocurrent response was significantly enhanced from -1% to -9.62%. These results bring key opportunity for graphene field effect transistor based photodetection, and the surface functionalization method are expected to help achieve high sensing performance on protein-based biosensors.