Researchers have developed a new way to measure particle to one millionth of a trillionth of a gram, according to a news release.
MIT engineers built their new measuring system base on technology developed by Scott Manalis, an MIT professor of biological and mechanical engineering, to weigh the mass of larger particles. The system is called suspended microchannel resonator (SMR) and measured mass of particles as they "flow through a narrow channel," according to a news release.
"Now we can weigh small viruses, extracellular vesicles, and most of the engineered nanoparticles that are being used for nanomedicine," Selim Olcum, a postdoc in Manalis' lab and one of the lead authors of the paper, said in a statement.
The scientists were able to shrink Manalis' system, increasing the solution to 0.85 attograms. The findings were published in a paper in Proceedings of the National Academy of Sciences:
To make the device sensitive to smaller masses, the researchers had to shrink the size of the cantilever, which behaves much like a diving board, Olcum says. When a diver bounces at the end of a diving board, it vibrates with a very large amplitude and low frequency. When the diver plunges into the water, the board begins to vibrate much faster because the total mass of the board has dropped considerably. To measure smaller masses, a smaller "diving board" is required.
"If you're measuring nanoparticles with a large cantilever, it's like having a huge diving board with a tiny fly on it. When the fly jumps off, you don't notice any difference. That's why we had to make very tiny diving boards," Olcum said.
The new system allows researchers to measure almost 30,000 particles in about 90 minutes, according to a news release.
"We're particularly excited about using the high precision of the SNR to quantify microvesicles in the blood of GBM patients. Although affinity-based approaches do exist for isolating subsets of microvesicles, the SNR could potentially provide a label-free means of enumerating microvesicles that is independent of their surface expression," Manalis said in a statement.
Click here to read more about the tiny particle measuring system.
