Detecting Explosives With Spinach

A team of engineers recently showcased an amazing application of spinach leaves. These can do wonders when embedded in carbon nanotubes. These engineers transformed the spinach plants in a sensor that is capable of detecting explosives substances. The research offers one of the first demonstrations towards the concept called plant nanobionics, a science that integrates electronic systems inside plants. The spinach plants we are talking about here have been designed to detect nitroaromatics, a special kind of chemical compound that is found in landmines and explosives. The idea is a pretty a straight one, when the presence of nitroaromatics is noticed in a groundwater sample absorbed by the plants, they will simply draw up their leaves. The team infused leaves of these plants with single-walled nanotubes (SWCNTs).

When a laser light is shone over these leaves, the SWCNTs get stimulated for emission of an almost-infrared fluorescent light. In this experiment, the engineers designed two types of SWCNTs, the first one changes with respect to nitroaromatic binding (B-SWCNTs) modifying the emitted signal while the other one acts as a reference. When signal intensities of these rays are compared with each other, you can easily find out if nitroaromatics are present in groundwater or not. For detection of infra-red signals, the research team used a single infrared camera that is hooked up with a Raspberry Pi system. A setup of this type is also capable of sending alerts to your computer or smartphone if explosives are detected. The team also claims that phone cameras without infrared filters can also be used for detection of signals.

It is an important research that will open up the doors of science for use of a large variety of environmental sensing applications. One of the team members, Michael Strano says, “Plants are very good analytical chemists. They have an extensive root network in the soil, are constantly sampling groundwater, and have a way to self-power the transport of that water up into the leaves.”