Spinach is certainly a godsend for Popeye's muscles, but that's probably the extent of its ability to help out in a fight. That is, unless it's blessed with the kind of nanotechnology MIT researchers are using.
To demonstrate the possibilities of a new field called "plant nanobionics," scientists embedded the leaves of spinach plants with carbon nanotubes that are capable of detecting nitroaromatics—compounds that are often used in landmines and other explosives. The plant takes in groundwater as a natural daily function, so if those compounds are present in the water, the plant will know about it. Within 10 minutes, the carbon nanotubes will emit a fluorescent signal. Infrared cameras pick up that signal and broadcast it to a smartphone-like device, which sends an email to actual humans so they can take whatever measures are necessary.