This technology has applications towards monitoring plant behavior, measuring pesticide levels in plans, and detecting environmental stresses, such as drought, salinity, and unusually high levels of UV-B radiation. It also has applications towards imaging cells and animal tissues.
Sensing molecules circulating in living organisms is a useful way to monitor structure, function, and overall health. However, in vivo sensors are often difficult to develop, due to the potential for toxicity and a lack of sensitivity resulting from the complexity of most biological tissues and high background or non-specific interactions.
Professor Michael Strano and colleagues have developed a method for in vivo sensing by measuring the relative emission intensities from a mixture of functionalized single-walled carbon nanotubes. The properties of the groups of nanotubes in the mixture can be adjusted such that each has a unique emission spectrum and binding target. The sensors can be passively delivered, and do not interfere with proper functioning of the organism. Moreover, the mixture also includes non-functionalized nanoparticles that serve as internal reference standards, thereby significantly reducing the effects of background noise. When used in plants, these particles have been shown to detect the reactive oxygen species nitric oxide and hydrogen peroxide, the signaling molecule dopamine, and the pesticide glyphosate.
- High specificity and sensitivity
- Easily synthesized and multiplexed
- Can be used in plant or animal cells and tissues