Lifeboat Foundation

Now, a discussion on Highly sensitive Plasmonic Nano-antenna arrays.

Plasmonic photoconductive antennas have great promise for increasing responsivity and detection sensitivity of conventional photoconductive detectors in time-domain terahertz imaging and spectroscopy systems. However, operation bandwidth of previously demonstrated plasmonic photoconductive antennas has been limited by bandwidth constraints of their antennas and photoconductor parasitics. Here, we present a powerful technique for realizing broadband terahertz detectors through large-area plasmonic photoconductive nano-antenna arrays. A key novelty that makes the presented terahertz detector superior to the state-of-the art is a specific large-area device geometry that offers a strong interaction between the incident terahertz beam and optical pump at the nanoscale, while maintaining a broad operation bandwidth. The large device active area allows robust operation against optical and terahertz beam misalignments. We demonstrate broadband terahertz detection with signal-to-noise ratio levels as high as 107 dB.

Nice.

CAMBRIDGE, Mass. — Determining the exact configuration of proteins and other complex biological molecules is an important step toward understanding their functions, including how they bind with receptors in the body. But such imaging is difficult to do. It usually requires the molecules to be crystallized first so that X-ray diffraction techniques can be applied — and not all such molecules can be crystallized.

Now, a new method developed by researchers at MIT could lead to a way of producing high-resolution images of individual biomolecules without requiring crystallization, and it could even allow zoomed-in imaging of specific sites within the molecules. The technique could also be applied to imaging other kinds of materials, including two-dimensional materials and nanoparticles.

The findings are reported this week in the Proceedings of the National Academy of Sciences, in a paper by Paola Cappellaro, the Esther and Harold E. Edgerton Associate Professor of Nuclear Science and Engineering at MIT, and others at MIT and at the Singapore University of Technology and Design.

Russian author Boris Zhitkov wrote the 1931 short story Microhands, in which the narrator creates miniature hands to carry out intricate surgeries. And while that was nearly 100 years ago, the tale illustrates the real fundamentals of the nanoscience researchers are working on today.

Nanoscience is the study of molecules that are one billionth of a metre in size. To put this into perspective, a human hair is between 50,000 and 100,000 nanometres thick. At this tiny size, materials possess properties that lie somewhere between a lump of metal and that of a single atom. This unique environment means they can become very reactive and be used as catalysts.

Continue reading “Five ways nanoscience is making science fiction into fact” »

Multiexcitonic transitions and emission of several photons per excitation comprise a very attractive feature of semiconductor quantum dots for optoelectronics applications. However, these higher-order radiative processes are usually quenched in colloidal quantum dots by Auger and other nonradiative decay channels. To increase the multiexcitonic quantum efficiency, several groups have explored plasmonic enhancement, so far with moderate results. By controlled positioning of individual quantum dots in the near field of gold nanocone antennas, we enhance the radiative decay rates of monoexcitons and biexcitons by 109 and 100 folds at quantum efficiencies of 60 and 70%, respectively, in very good agreement with the outcome of numerical calculations. We discuss the implications of our work for future fundamental and applied research in nano-optics.

A NASA technologist has teamed with the inventor of a new nanotechnology that could transform the way space scientists build spectrometers, the all-important device used by virtually all scientific disciplines to measure the properties of light emanating from astronomical objects, including Earth itself.

Mahmooda Sultana, a research engineer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, now is collaborating with Moungi Bawendi, a chemistry professor at the Cambridge-based Massachusetts Institute of Technology, or MIT, to develop a prototype imaging spectrometer based on the emerging quantum-dot technology that Bawendi’s group pioneered.

Nice.

A Nanotech company came up with a way for fingerprints to stay invisible on glass and metal surfaces: Nanotechnology is taking us to new and unique places.

CRISPR/Cas9, a powerful gene editing technique that has already been used in a human, is thought by many as a “cut and paste” for DNA in living organisms. While in a sense that is what happens, delivering the ribonucleoprotein that does the genetic editing and the RNA that hones in on the target, into the cellular nucleus without being damaged is a challenge. That is why the efficiency of successful edits remains very low. Researchers at University of Massachusetts Amherst have now come up with nanoparticles that protect the protein and RNA as they’re brought to their work site.

The nanoparticles are engineered around their cargo and have shown a 90% success rate of getting the cargo into the nucleus, and a 30% editing efficiency, which is “remarkable” according to the researchers. So far the team has tested their technique on cultured cells, but they’re already working on trying the same in laboratory animals. As part of their research, they developed a novel way of tracking the Cas9 protein inside the cells, something that will certainly help other scientists in this area.

“By finely tuning the interactions between engineered Cas9En protein and nanoparticles, we were able to construct these delivery vectors. The vectors carrying the Cas9 protein and sgRNA come into contact with the cell membrane, fuse, and release the Cas9:sgRNA directly into the cell cytoplasm,” in a statement said Vincent Rotello, lead author of the study in ACS Nano. “Cas9 protein also has a nuclear guiding sequence that ushers the complex into the destination nucleus. The key is to tweak the Cas9 protein,” he adds. “We have delivered this Cas9 protein and sgRNA pair into the cell nucleus without getting it trapped on its way. We have watched the delivery process live in real time using sophisticated microscopy.”

Continue reading “Nanoparticles Deliver CRISPR/Cas9 Genetic Editor Safely Into Cells” »

Quantum mechanics, the physics that governs nature at the atomic and subatomic scale, contains a host of new physical phenomena to explore quantum states at the nanoscale. Though tricky, there are ways to exploit these inherently fragile and sensitive systems for quantum sensing. One nascent technology in particular makes use of point defects, or single-atom misplacements, in nanoscale materials, such as diamond nanoparticles, to measure electromagnetic fields, temperature, pressure, frequency and other variables with unprecedented precision and accuracy.

Quantum sensing could revolutionize medical diagnostics, enable new drug development, improve the design of electronic devices and more.

For use in quantum sensing, the bulk nanodiamond crystal surrounding the point defect must be highly perfect. Any deviation from perfection, such as additional missing atoms, strain in the crystalline lattice of the diamond, or the presence of other impurities, will adversely affect the quantum behavior of the material. Highly perfect nanodiamonds are also quite expensive and difficult to make.

Nice.

Nanorobots and other mini-vehicles might be able to perform important services in medicine one day – for example, by conducting remotely-controlled operations or transporting pharmaceutical agents to a desired location in the body. However, to date it has been hard to steer such micro- and nanoswimmers accurately through biological fluids such as blood, synovial fluid or the inside of the eyeball.

Researchers at the Max Planck Institute for Intelligent Systems in Stuttgart are now presenting two new approaches for constructing propulsion systems for tiny floating bodies. In the case of one motor, the propulsion is generated by bubbles which are caused to oscillate by ultrasound (Applied Physics Letters, “Wireless actuation with functional acoustic surfaces”). With the other, a current caused by the product of an enzymatic reaction propels a nanoswimmer (JACS, “Bubble-Free Propulsion of Ultrasmall Tubular Nanojets Biocatalytic Reactions”).

Continue reading “New drive for nanorobots in biological fluids” »