Hexagonal Boron Nitride Spacers for Fluorescence Imaging of Biomolecules

Hexagonal Boron Nitride Spacers for Fluorescence Imaging of Biomolecules

Yang, X. (TU Delft Dynamics of Micro and Nano Systems)
Shin, D. (TU Delft Dynamics of Micro and Nano Systems)
Yu, Z. (TU Delft Dynamics of Micro and Nano Systems)
Watanabe, Kenji (National Institute for Materials Science)
Taniguchi, Takashi (National Institute for Materials Science)
Babenko, Vitaliy (University of Cambridge)
Hofmann, Stephan (University of Cambridge)
Caneva, S. (TU Delft Dynamics of Micro and Nano Systems)

2024

Fluorescence imaging is an invaluable tool to investigate biomolecular dynamics, mechanics, and interactions in aqueous environments. Two-dimensional materials offer large-area, atomically smooth surfaces for wide-field biomolecule imaging. Despite the success of graphene for on-chip biosensing and biomolecule manipulation, its strong fluorescence-quenching properties pose a challenge for biomolecular investigations that are based on direct optical readouts. Here, we employ few-layer hexagonal boron nitride (hBN) as a precisely tailorable fluorescence spacer between labelled lipid membranes and graphene substrates. By stacking high-quality hBN crystals in the 10–20 nm thickness range on monolayer graphene, we observe distance-dependent fluorescence intensity variations. Remarkably, with hBN spacers as thin as 20 nm, the fluorescence intensity is comparable to bare SiO₂/Si substrates, while the intensity was reduced to 60 % and 80 % with ~10 nm and ~16 nm hBN thicknesses respectively. We confirm that pre-determined hBN thicknesses can be employed to control the non-radiative energy transfer properties of graphene, with fluorescence quenching following a d⁻⁴ distance-dependent behaviour. This seamless integration of electronically active and dielectric van der Waals materials into vertical heterostructures enables multifunctional platforms addressing the manipulation, localization, and visualization of biomolecules for fundamental biophysics and biosensing applications.

fluorescence
graphene
hexagonal boron nitride (hBN)
lipids
quenching

http://resolver.tudelft.nl/uuid:cf120d58-14a9-425a-b26f-0562b402a494

https://doi.org/10.1002/cnma.202300592

2199-692X

ChemNanoMat, 10 (5)

D.H.S. and S.C. acknowledge funding from the European Union's Horizon 2020 research and innovation program (ERC StG, SIMPHONICS, Project No. 101041486). S.C. acknowledges a Delft Technology Fellowship. X.Y. acknowledges funding from the Chinese Scholarship Council (Scholarship No. 202108270002). Z.Y. acknowledges funding from NWO (Project MechanoPore).

Institutional Repository

journal article

© 2024 X. Yang, D. Shin, Z. Yu, Kenji Watanabe, Takashi Taniguchi, Vitaliy Babenko, Stephan Hofmann, S. Caneva