Tailoring Metal–Organic Frameworks

Felipe Gándara et al. at Materials Science Institute of Madrid has developed a new method to prepare metal–organic frameworks with specific combinations of metal elements. The funny thing (to me) is that this method reminds me of how ribosomes build proteins.

Using molecular complexes with the desired metal-atom combinations as building blocks, they’re able to synthesize these frameworks with precise atomic composition. This method will allow to increase the different ways we have now to create extremely tailored novel materials that might be used for heterogeneous catalysis or quantum computing.

Their work has been featured in the cover of JACS.

Memristors Showing and Resistive Switching

Our good friend Prof. Mario Lanza is doing great at his new position in KAUST. And his last article has been featured in the cover of Advanced Electronic Materials. I this work they discuss the operating temperature of memristors which happen to be very low, making them suitable for electronic devices with low consumption.

The synaptic connection

It is easy to understand how important the formation of correct synaptic connections is during neural circuitry formation. The Teneurin family of proteins promotes these connections between cells playing an essential role in neuron-neuron adhesion.

At the Kavli Institute of Nanoscience (TUDelft) together with the Utrecht University have resolved the dimeric ectodomain of human Teneurin4 structure with 2.7 Å resolution. In the world of proteins, structure is directly related to function. And this amazing research, which has been featured in the cover of EMBO Journal, supports the role for teneurins as a scaffold for macromolecular complex assembly and the establishment of cis- and trans-synaptic interactions to construct functional neuronal circuits.

We made this picture to illustrate the behaviour of Teneurin, closely advised by Dr. Dimphna Meijer.

La Saga de la Tercera Hija

What if we told the history of the Earth as a creation myth? This is La Saga de la Tercera Hija, which sadly does not have an English version yet. A very personal project that I’ve enjoyed making during the last couple of years. Hope you enjoy it too. Download it here!

 

A strange couple of years…

It’s been a strange couple of years with worldwide issues that have affected us all. But here at Scixel, we can be nothing but grateful. First of all, the pandemic didn’t affect us in a serious way, neither us nor our families. Second, our clients continued with their usual hard work from home. And that deserves a huge ovation for the scientists all over the world. Their effort did not only kept us on business, but in better shape than ever. And finally, we kept working with Filmociencia and started working with Patricia Bondia, and that alone is something to be grateful for.

Here I leave you with a short summary of our work during the last two years. And as always, thank you all for making Scixel possible.

 

The Keymaster and the Gatekeeper

The study of single proteins has always been tricky. First of all you need to locate them. Until today, most of the solutions involved the labeling of the molecules an then their attachment to something else: links, surfaces, etc. And the problem gets trickier if you want to study their dynamics.

A new promising technique that solves most of these problems has been recently proposed. Scientists at the Kavli Institute of Nanoscience together with the Technische Universität München, have managed to create what they’ve called the NEOtrap: a functional nanopore electro-osmotic trap. As they describe it, “the NEOtrap is formed by docking a DNA-origami sphere onto a passivated solid-state nanopore, which seals off a nanocavity of a user-defined size and creates an electro-osmotic flow that traps nearby particles irrespective of their charge“.

This new technique, featured on the cover of Nature Nanotechnology, is another interdisciplinary finding at the intersection of biology and physics and it opens the door to the study of label-free single proteins dynamics.

We made this picture, under the close supervision of Sonja Schmid (first author) and Cees Dekker (last author) who is an old friend that always brings us cool, new exciting stuff to work with.

Cool radio waves

How do you cool radio waves? Do waves have a temperature in the first place? Common waves are hot meaning they are noisy. There are multiple sources of noise in the generation process of waves and some of them are related to temperature. One of these sources, and probably the most difficult to remove, comes from the intrinsic random motion of atoms.

A possible solution would be to conventionally cool down the antennas that emit the waves. But even at temperatures of miliKelvin, the jiggling of atoms produce a significant amount of noise.

A group of researchers at TuDelft led by Prof. Gary Steel have managed to cool radio waves to their quantum ground state and the process is as surprising as it is difficult to grasp. They’ve placed a circuit close to the antenna that gets coupled to it via its magnetic field. This circuit then acts as a “vaccum cleaner” that absorbs entropy from the antenna cooling it down.

This cooling process and subsequent noise reduction, published in Science Advances, will be of the utmost importance in detectors in a wide range of devices and purposes: from NMR to astronomical detectors.

We made this animation with the help of Dr. Ines Rodrigues (first author of the paper) and Prof. Gary Steele to illustrate the process.

 

Hyperlenses

This has been a good year for nano optics. And the research group 2DNanoptica (Oviedo, Spain) is largely responsible for this. Leading international collaborations, they’ve published two major advances in high impact factor journals during 2021.

In the first one, published in Nature Communications, they’ve presented a study on the refraction of light in highly anisotropic materials at the nanoscale. They’ve shown how light shows an exotic behaviour under this circumstances: how it can propagate in non-intuitive directions or how the refracted waves can be highly confined. Using these principles, they’ve built nanometric lens able to focus light in spaces way smaller that its wavelength.

In the second one, published in Science Advances, they show a similar result, but this time using two gold nano antennas, shaped in a special way that allows to focus light with a high level of confinement.

These results have obvious applications in optical computation or communications. But also they can work as biological or atmospheric sensors. However that does not really matter, does it? Because this work (both theoretical and experimental) is just beautiful. And that should be enough.

 

We did this two pictures in collaboration with Patricia Bondía to illustrate this work under close supervision of Pablo Alonso-González and Javier Martín Sánchez.

Mapping energy carriers

How can we map out traps on a surface? Ferry Prins, Michael Seitz et al. have developed a curious strategy. First, they’ve injected a small population of excitons (gaussian shaped) in a 2D metal halide perovskite. The flow of these excitons through the material will be affected by the traps, kind of how the flow of water is affected by stones at the riverbed. Therefore, by visualising the flow of the excitons, you can “accurately map out the trap-state landscape in the perovskite lattice”.

This research, has been featured in the cover of Advanced Optical Materials. The picture has been done under the supervision of Ferry Prins and Michael Seitz.

Van der Waals on paper

We’ve been talking for quite a long time about the crazy things that happen in Andres Castellanos’s Lab. And they seem to be getting crazier. The ability of this people for outside the box thinking is amazing. Actually they don’t seem to know about the box at all!

They are now working in the use of paper as a functional substrate for van der Waals materials. This materials are deposited by “simply rubbing the vdW crystals against the rough surface of paper”. The aim is to replace silicon with a cheap material. But is it paper a valid substrate? In this new work, they’ve characterized the optical and electronic properties of some of this materials in this strange new conditions. As vdW materials can behave as superconductors, insulators, semiconductors or semi-metals, researchers have to prove all these properties are maintained when transferred into paper.

And that is exactly what they did by building field-effect devices using the paper substrate as an ionic gate. This work, published in Applied Materials Today, has been featured in the cover.