Hybrid Graphene-Based Photonic-Plasmonic Biochemical Sensor with a Photonic and Acoustic Cavity Structure

Abstract

In this study, we propose a biochemical sensor that features a photonic cavity integrated with graphene. The tunable hybrid plasmonic-photonic sensor can detect the molecular fingerprints of biochemicals with a small sample volume. The stacking sequence of the device is “ITO grating/graphene/TiO2/Au/Si substrate”, which composes a photonic band gap structure. A defect is created within the ITO gratings to form a resonant cavity. The plasmonic-photonic energy can be confined in the cavity to enhance the interaction between light and the analyte deposited in the cavity. The finite element simulation results indicated that the current sensor exhibits very high values in resonance shift and sensitivity. Moreover, the resonance spectrum with a broad resonance linewidth can identify the molecular vibration bands, which was exemplified by the fingerprint detections of protein and the chemical compound CBP. The sensor possesses an electrical tunability by including a graphene layer, which allowed us to tune the effective refractive index of the cavity to increase the sensor’s sensing performance. In addition, our device admits a phononic bandgap as well, which was exploited to sense the mechanical properties of two particular dried proteins based on the simplified elastic material model instead of using the more realistic viscoelastic model. The dual examinations of the optical and mechanical properties of analytes from a phoxonic sensor can improve the selectivity in analyte detections.

Applications of Graphene-Based Materials in Sensors: A Review

“…Applying different bias voltages to graphene can change its Fermi level, so the optical properties of the resonator will also change. Some researchers use this adjustable property of graphene to improve the performance of the sensor and change the reso- (c1) Structure diagram and cross-section diagram of resonant cavity plasma photon biochemical sensor [68]; (d1) Effect of adjusting Fermi level of graphene on the sensitivity and wavelength of the sensor [68].…”

“…Applying different bias voltages to graphene can change its Fermi level, so the optical properties of the resonator will also change. Some researchers use this adjustable property of graphene to improve the performance of the sensor and change the resonance wavelength to study fingerprint detection [68]. The resonant cavity plasma photon biochemical sensor proposed in this paper is shown in Figure 3(c1).…”