Electrically controlled molecular fingerprint retrieval with van der Waals metasurface

Polaritons in two-dimensional van der Waals (vdW) materials possess extreme light confinement, which have emerged as a potential platform for next-generation biosensing and infrared spectroscopy. Here, we propose an ultra-thin and electric tunable graphene/hexagonal boron nitride/graphene metasurface for detecting molecular fingerprints over a broad spectrum. The vdW metasurface supports hybrid plasmon-phonon polariton resonance with high-quality factor (Q > 120) and electrically controlled broadband spectra tunability from 6.5 to 7 mu m. After coating a thin layer of bio-molecular (e.g., CBP) on top of the metasurface, the molecular absorption signatures can be readout at multiple spectral points and, thus, achieve broadband fingerprint retrieval of bio-molecules. Additionally, our electric tunable metasurface works as an integrated graphene-based field-effect transistor device, without the need of multiple resonance generators such as angle-resolved or pixelated dielectric metasurfaces for broadband spectra scanning, thereby paving the way for highly sensitive, miniaturized, and electrically addressed biosensing and infrared spectroscopy. Published under an exclusive license by AIP Publishing.

Automated summary

This study proposes an ultra-thin and electric tunable graphene/hexagonal boron nitride/graphene metasurface for detecting molecular fingerprints. The metasurface supports hybrid plasmon-phonon polariton resonance with high-quality factor and can achieve tunability over a broad spectrum. This method enables broadband fingerprint retrieval of bio-molecules and paves the way for highly sensitive, miniaturized, and electrically addressed biosensing and infrared spectroscopy.