Nano-Sensor Detects SARS-CoV-2

Using specialized carbon nanotubes, MIT engineers have designed a novel sensor that can detect SARS-CoV-2 without any antibodies, giving a result within minutes. Their new sensor is based on technology that can quickly generate rapid and accurate diagnostics, not just for Covid-19 but for future pandemics, the researchers say.

Using specialized carbon nanotubes, MIT engineers have designed a novel sensor that can detect SARS-CoV-2 without any antibody, giving a result within minutes.

A rapid test means that you can open up travel much earlier in a future pandemic. You can screen people getting off of an airplane and determine whether they should quarantine or not. You could similarly screen people entering their workplace and so forth,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the study. “We do not yet have technology that can develop and deploy such sensors fast enough to prevent economic loss.”

The diagnostic is based on carbon nanotube sensor technology that Strano’s lab has previously developed. Once the researchers began working on a Covid-19 sensor, it took them just 10 days to identify a modified carbon nanotube capable of selectively detecting the viral proteins they were looking for, and then test it and incorporate it into a working prototype. This approach also eliminates the need for antibodies or other reagents that are time-consuming to generate, purify, and make widely available.

Several years ago, Strano’s lab developed a novel approach to designing sensors for a variety of molecules. Their technique relies on carbon nanotubeshollow, nanometer-thick cylinders made of carbon that naturally fluoresce when exposed to laser light. They have shown that by wrapping such tubes in different polymers, they can create sensors that respond to specific target molecules by chemically recognizing them.

Their approach, known as Corona Phase Molecular Recognition (CoPhMoRe), takes advantage of a phenomenon that occurs when certain types of polymers bind to a nanoparticle. Known as amphiphilic polymers, these molecules have hydrophobic regions that latch onto the tubes like anchors and hydrophilic regions that form a series of loops extending away from the tubes.

MIT postdoc Sooyeon Cho and graduate student Xiaojia Jin are the lead authors of the paper, which appears today in Analytical Chemistry. Other authors include MIT graduate students Sungyun Yang and Jianqiao Cui, and postdoc Xun Gong.

Source: https://news.mit.edu/

Portable Machine Harvests Water From Air

Driven by the scarcity of supply, climate change and ground watershed depletion, scientists present a design for a first of its kind portable harvester that mines freshwater from the atmosphere. For thousands of years, people in the Middle East and South America have extracted water from the air to help sustain their populations. Researchers and students from the University of Akron drew inspiration from those examples to develop a lightweight, battery-powered freshwater harvester that could someday take as much as 10 gallons (37,8 liters) per hour from the air, even in arid locations.

I was visiting China, which has a freshwater scarcity problem. There’s investment in wastewater treatment, but I thought that effort alone was inadequate,University of Akron professor Shing-Chung (Josh) Wong said.

Instead of relying on treated wastewater, Wong explained, it might be more prudent to develop a new type of water harvester that takes advantage of abundant water particles in the atmosphere. Freshwater makes up less than 3 percent of the earth’s water sources, and three quarters of that is locked up as ice in the north and south poles. Most water sustainability research is directed toward water supply, purification, wastewater treatment and desalination. Little attention has been paid to water harvesting from atmospheric particles.

Harvesting water from the air has a long history. Thousands of years ago, the Incas of the Andean region collected dew and channeled it into cisterns. More recently, some research groups have been developing massive mist and fog catchers in the Andean mountains and in Africa. Wong’s harvester is directed towards the most abundant atmospheric water sources and uses ground-breaking nanotechnology. If successful, it will produce an agile, lightweight, portable, freshwater harvester powered by a lithium-ion battery.

By experimenting with different combinations of polymers that were hydrophilic — which attracts water — and hydrophobic — which discharges water, the team concluded that a water harvesting system could indeed be fabricated using nanofiber technology. Unlike existing methods, Wong’s harvester could work in arid desert environments because of the membrane’s high surface-area-to-volume ratio. It also would have a minimal energy requirement. “We could confidently say that, with recent advances in lithium-ion batteries, we could eventually develop a smaller, backpack-sized device,” Wong said.

Source: https://www.uakron.edu/