The Method for the Self-Powered Detection of Nitroaromatics Using a Wild Type Plant

Technology #18319

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The functionalized leaf was gently held in place on glass slides and exposed to 785 nm laser excitation on a microscope stage and the emission intensity of both B-SWCNTs and P-SWCNTS recorded at two specific x-y spatial positions. Approximately 0.4 mM of picric acid was then placed into the beaker in which the plant roots were submerged and left for an hour.nIR fluorescence spectra of PVA-SWCNT and Bombolitin-SWCNT in response to picric acid in vitro.Diagrammatic depiction of standoff detection set-up with the nanohionic sensing plant. The plant can be modelled as a sequence of reactors in series.Brightfield image of spinach plant leaf infiltrated with SWCNT and under 785 nm excitation. P-SWCNT and B-SWCNT indicated by black and red arrows respectively. Temporal changes in nIR fluorescence of a plant infiltrated with B-SWCNT and P-SWCNT is monitored as picric acid is transported from the roots to the leaves via the plain vascular system. While P-SWCNT nR fluorescence remains stable. the B-SWCNT intensity drops as leaves transpire a solution of picric acid (400 tiM) in 10mM KU]. tilR images were taken with a 900 long pass filter. SWCNT inside leaves were excited with 785 nm laser at 15 mW.
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Inventors
Professor Michael Strano
Department of Chemical Engineering, MIT
External Link (srg.mit.edu)
Min Hao Wang
Department of Chemical Engineering, MIT
Juan Giraldo
Department of Chemical Engineering, MIT
Seon-Yeong Kwak
Department of Chemical Engineering, MIT
Managed By
Jon Gilbert
MIT Technology Licensing Officer
Patent Protection

Sensor for Infrared Communication using Plant Nanbiotics

PCT Patent Application Filed

Applications

Nanobionic plant sensors can be utilized in a wide range of applications, including but not limited to monitoring  of soil nutrient content, detection of potentially hazardous chemicals in groundwater, alerting for buried explosives, and quantification of atmospheric gas content. 

Problem Addressed

A nanobionic approach to the development of plant sensors bypasses the constraints that previous methods have experienced. In the past, plant sensors were created through genetic modifications. These approaches are limited to plants that have been extensively studied and well-understood, such as the tobacco plant; furthermore, they require long periods of time to perfect. On the other hand, nanobionic sensing mechanisms can be developed and tested very quickly, and mechanisms developed for one species are often easily translatable to another. In brief, nanobionic engineering provide results that are both more versatile and more efficiently obtained. 

Technology

In this invention, plant sensors are created by infiltrating leaves with single-walled carbon nanotubes (SWCNTs) embedded with macromolecules. Embedded SWCNTs emit near infrared (nIR) signals in response to laser excitation at 785 nm.  Exposure of these SWCNTs to other macromolecules either attenuates or shifts their emission spectrum, which can then be recorded by a standoff detector placed a meter away. In one iteration of this invention, SWCNTs embedded with bombolitin can be used to detect picric acid, a nitroaromatic compound commonly found in explosives. When picric acid is absorbed from ground water and delivered through the symplastic pathway from the roots to the plant xylem and leaves, it quickly decreases the fluorescence of the SWCNTs embedded in the leaves. SWCNT-embedded spinach leaves showed a drop in emission intensity only 5-15 mintues after picric acid exposure to the roots of the plant. Quenching of fluorescence reached its maximum at 60 minutes, when the emission intensity was only on average 85% of the original intensity. When picric acid droplets were absorbed directly into the leaf cuticles, quenching of nIR emission was detected at 10 s and fluorescence signal reached a plateau at 400 s. This invention could be extended to include different nIR detector components and hand-held signal receivers,  as well as to enable surreptitious, self-powered monitoring of a wide variety of environmental conditions.

Advantages

  • Remote, self-powered sensing
  • Quickly developed
  • Trans-species applicability
  • Real-time monitoring capability