Electrically tunable plasmonic biosensors based on cavity-coupled structure with graphene

Chan Shan Yang*, Yi Cheng Chung*, Yi Sheng Cheng, Young Chou Hsu, Ciao Fen Chen, Nan Nong Huang*, Hung Cheng Chen*, Chien Hao Liu*, Jin Chen Hsu*, Yen Fu Lin*, Tzy Rong Lin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


In this research, we proposed a highly tunable hybrid plasmonic biosensor for identifying molecule fingerprints of proteins in the infrared range. The device is composed of a photonic band-gap structure and a cavity. The plasmonic energy is confined inside the cavity to enhance the light-analyte interactions. A layer of graphene is placed on the bottom surface of the cavity that is filled with analytes for detection. Our device has a high value of effective sensitivity that is defined as the ratio of the resonant frequency shift to the change of effective refractive index when the cavity is loaded with an analyte. The effective refractive index takes into account the effects of both the cavity structure and the optical property of the analyte. Another feature of our device is that a wide-ranging electrical tunability can be realized by applying various values of bias voltage to the graphene. The resonant frequency can be tuned for sensing different analytes without redesigning and refabricating the device. In addition, the graphene tunability can improve the sensitivity in detecting the non-targeted analytes. A prototype was designed based on photonic theory and fabricated via bottom-up lithography techniques. The research results are expected to be beneficial for nanometer-range bio-identifications and infrared optical sensors.

Original languageEnglish
Article number9298832
JournalIEEE Journal of Selected Topics in Quantum Electronics
Issue number4
Publication statusPublished - 2021 Jul 1


  • Effective sensitivity
  • graphene tunability
  • hybrid plasmonic biosensors

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


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