▎ 摘　　要

We theoretically design and analyze a novel, real-time and label-free highly sensitive biosensor made of a plasmonic nanofiber waveguide. We employ metal, metamaterial and graphene interfaces with dielectrics in waveguides to introduce two different biosensor configurations. Both configurations consist of a U-shape nanofiber structure; the first configuration is coupled to a sample housing and the second configuration is dipped into the sample. To check the capability and functionality of the biosensors, we employ three different cancerous cells including blood, adrenal glands and cervical cancers. The presence of graphene in the biosensor structures facilitates the design of tunable sensors with the capability to operate at different frequencies with different sensitivities. Our structure has a high sensitivity of 2565.7THZ/RIU for adrenal gland, and 2575THZ/RIU for the blood cancer. The proposed biosensor structures are compact and easy to fabricate with applications in disease diagnosis and chemical sensing.