January 13, 2014
KI faculty member Scott Manalis has created a new sensor that can measure weights at the attogram scale, or one millionth of a trillionth of a gram. This work appears in the Proceedings of the National Academy of Sciences and also involves KI faculty members Angela Belcher and Sangeeta Bhatia.
Manalis developed an earlier version of the device, called a suspended microchannel resonator. It measures the mass of living cells as they flow through a narrow channel etched in a tiny silicon cantilever that behaves like a diving board. His team subsequently used it to track the growth and other physical properties of cancer cells such as density, stiffness, and friction. Now, by shrinking the entire system, the researchers have improved its resolution 30-fold. This allows them to weigh small viruses, extracellular vesicles, and nanoparticles to better understand their composition and function. The Manalis team plans to use the new suspended nanochannel resonator for high-precision detection and monitoring of cancer progression and treatment response. For example, glioblastoma tumors secrete large quantities of biological vesicles known as exosomes, and the investigators are using their new device to detect exosomes in blood samples of patients with this type of brain cancer.