[SciShow intro plays]

Hi, I’m Caitlin Hofmeister from SciShow Space, filling in to bring you today’s SciShow News. I think we can all agree that plants are pretty important, giving us food, breathable air, and medicine. But a plant is... a plant. And unless you’re somewhere like Middle Earth, plants aren’t going to talk to you, right?

Well, get this: In a study published in the journal Nature Materials this week, engineers created hybrid spinach plants that can detect explosives. And not only that, they can signal a computer to send you an email about it. This is just one example of what the researchers call plant nanobionics, combining everyday plants and electronic nanotechnology.

The key to these super-sleuthing spinach plants are carbon nanotubes in their leaves, which are designed to detect whatever chemicals the researchers want. To embed the nanotubes, the engineers used a process called vascular infusion. Basically, they squirted the underside of the spinach leaves with a solution of nanotubes, water, and other chemicals, like the detergent sodium cholate.

The nanotubes are so tiny that they squeezed through the leaf’s pores and into the mesophyll tissue. So as the plant sucked up groundwater through its roots, a bunch of nutrients and other chemicals spread to its cells and bumped up against the embedded carbon nanotubes. In this study, the nanotubes were linked to a protein that specifically binds to nitroaromatics, which are reactive chemicals used in landmines and other explosives. That binding changes the nanotube’s chemistry and makes it emit an infrared fluorescent signal.

The researchers also stuck in some nanotubes that were sending a signal all the time to act as a reference point. That way, a nearby infrared camera could detect extra infrared signaling because of nitroaromatics, and tell a computer to send a “WARNING: there are explosives nearby” e-mail report. Theoretically, you could use these plants to detect things like buried landmines, but the researchers have a lot of other ideas for what plant nanobionics could do.

See, plants are really great at monitoring the environment, from groundwater to the air. They’re able to detect things like drought, or chemical spills more easily than we can. So, we just have to figure out how to listen to them. So, this explosive-detecting spinach might just be the beginning. And thanks to plant nanobionics, “superfoods” are getting a whole new meaning.

Meanwhile, in human news, if you’ve ever been upset about the lack of male birth control options: scientists are working on it. A recent study published in the Journal of Clinical Endocrinology and Metabolism showed that a set of hormone shots for men seems to prevent their partners from getting pregnant. These shots have been studied in smaller tests before, and this research is still pretty preliminary. It was mainly to see if this birth control worked on a slightly larger scale, and whether there were any unsafe side effects.

The study was broken into two main phases, and started with 320 men in heterosexual relationships. In the suppression phase, they received two hormone shots every 8 weeks for up to about half a year. The first shot was 200 milligrams of a progestogen steroid, which was similar to compounds found in some female birth controls.

And the second was 1000 milligrams of a steroid called TU, which is a slightly modified testosterone molecule, and an androgen. Basically, these hormones interfere with the sperm growth cycle in specialized cells in the testes. The goal was to decrease sperm counts by 99% or more, and sperm counts are usually anywhere from 40 to 300 million sperm per milliliter.

And within 6 months, over 270 of the 320 participants had sperm counts below 1 million per milliliter, and moved on to the efficacy phase. Of the people who didn’t move on, only two didn’t make the sperm count cut -- the others just stopped participating. Now, during the first phase of testing, the participants and their partners used non-hormonal birth control, like condoms, during sex.

But during this phase, they were asked to rely completely on the injections for over a year. And the results? There were only 4 pregnancies out of the 266 men that stuck with the study, which is pretty effective for birth control! And most of those men went back to producing sperm as per usual after stopping the shots.

All this sounds pretty promising. In fact, more than three-quarters of the participants said they’d be happy to keep using this birth control. But there were also a lot of side effects -- almost 1500 reports in total, although the researchers figured around 40% of them weren’t related to the injections. Still, participants reported muscle pains, increased acne, and mood disorders, which are risks that the researchers want to work on before this method is widely used. Male hormonal birth control has been in the works for a while, so hopefully when one method will make it through more clinical trials, and be a promising new choice. And maybe this will be it!

Thanks for watching this episode of SciShow News, brought to you by our patrons on Patreon. If you want to help support this show, go to Patreon.com/SciShow. And don’t forget to go to YouTube.com/SciShow and subscribe! And if you wanna see more of me, or Hank, or Reid Reimers, go to YouTube.com/scishowspace!