Tracking molecules one by one in a very small scale using 2D matter

A discovery in the field of nanofluids could revolutionize our understanding of molecular behavior at the nanoscale. Research teams fromEPFL And theUniversity of Manchester They have revealed a previously hidden world using newly discovered fluorescent properties of a two-dimensional graphene-like material, boron nitride.

This innovative approach allows scientists to track individual molecules within nanofluidic structures, and reveal their behavior in new ways. The results of the study are published in the journal Nature materials.

Unexpected fluorescence of boron nitride

there Nanofluids, which is the study of fluids confined to very small spaces, provides insight into the behavior of fluids at the nanoscale. However, exploring the movement of single molecules in such confined environments has been difficult due to limitations of conventional microscopy techniques. This obstacle has prevented real-time detection and imaging, leaving significant gaps in our knowledge of the molecular properties of confinement.

Thanks to an unexpected property of boron nitride, EPFL researchers have achieved what was previously considered impossible. This two-dimensional material has the remarkable ability to emit light when in contact with liquids. By taking advantage of this property, scientists from the Nanoscale Biology Laboratory at EPFL were able to achieve this I was able to directly observe and track the trajectories of individual molecules within nanofluidic structures.

This discovery paves the way for a deeper understanding of the behaviors of ions and molecules under conditions that mimic biological systems.

Monitoring one molecule after another

Professor Aleksandra Radinovic, President of LBEN, explains: “ Advances in manufacturing and materials science have allowed us to control ionic and fluid transport at the nanoscale. However, our understanding of nanofluidic systems has remained limited, as conventional optical microscopy has been unable to penetrate structures below the diffraction limit. Our research now sheds light on nanofluids, providing insight into an area that has been largely unexplored to date. »

This new understanding of molecular properties has exciting applications, including the ability to directly image emerging nanofluidic systems, where fluids exhibit unconventional behaviors under pressure or electrical stimuli. The essence of the research lies in the fluorescence from single photon emitters on the surface of hexagonal boron nitride.

” This fluorescence activation was unexpected, as neither hBN nor the liquid showed fluorescence in the visible spectrum alone. It most likely comes from the interaction of molecules with surface defects on the crystal, but we are still unsure of the exact mechanism “, explains Nathan Ronceray, PhD student at LBEN.

Promising applications

Designed by Professor Radha Boya from the Department of Physics at Manchester Nanochannels from 2D materials, confining the liquids to only a few nanometers from the hBN surface. This partnership made it possible to visually inspect these systems, detecting indicators of a confinement-induced liquid system.

” Seeing is believing, but it is not easy to see the effects of incarceration on this scale. We make these extremely thin slit-shaped channels, and the current study shows an elegant way to visualize them using super-resolution microscopy “, says Radha Pooya.

The potential of this discovery is very great. Nathan Ronceray envisions applications beyond simple passive detection. ” We have mainly observed the behavior of hBN-containing molecules without actively interacting with them, but we believe it can be used to visualize nanoscale flows generated by pressure or electric fields. »

This could lead to more dynamic applications in the future for optical imaging and sensing, providing unprecedented insights into the complex behaviors of molecules in these confined spaces.

Synthetic

This landmark discovery in the field of nanofluids opens new horizons for understanding the behavior of molecules at the nanometer scale. Thanks to the unexpected fluorescence properties of boron nitride, it is now possible to track individual molecules in nanochannels, revealing their pathways and interactions. This advance makes it possible to envision promising future applications in optical imaging and nanoscale detection.

For better understanding

What property of boron nitride enabled this advance?

Boron nitride unexpectedly has the ability to emit light when in contact with liquids confined in nanochannels.

This fluorescence makes it possible to optically tag and track individual molecules, revealing their trajectories in nanofluidic space.

What does this offer compared to previous technologies?

Conventional microscopy techniques did not allow imaging at these sub-nanometre scales. This progress thus opens a new field of study.

What are the intended applications?

This paves the way for new imaging and optical sensing techniques at the nanoscale to study confined fluids.

What phenomena can be observed now?

We can observe the trajectories of individual molecules, their interactions, as well as the effects of liquid confinement at the nanoscale.

What challenges still need to be overcome?

We still need to precisely understand the origin of fluorescence and develop techniques to actively interact with the traced molecules.

Keynote Annotation: A look at how new research is unraveling the mystery of molecular motion in narrow nanometer spaces. – Source: Tetouan Viwit / EPFL

References Ronceray, N., You, Y., Glushkov, E., Lihter, M., Rehl, B., Chen, T.-H., Nam, G.-H., Borza, F., Watanabe, K. ., Taniguchi, T., Rock, S., Kirthi, A., Comtet, J., Radha, P., and Radinovic, A. (2023). Liquid-activated quantum emission from pristine hexagonal boron nitride for nanofluidic sensing. Nature materials. doi: 10.1038/s41563-023-01658-2

The article is adapted from the content by the author: Michael David Mitchell

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