Hi all! If you follow me on Twitter, you may have noticed that I’ve mentioned Science Uncovered a few times lately…. the reason is, I have had an article published as the main cover story on the May issue that fantastic magazine! Cue me talking pictures of the magazine in-situ everywhere – Waterloo, Heathrow Airport, Ireland…. tragic I know, but it is very exciting! There were a few edits / additions to the final published piece that made me a little bit twitchy (typical physicist), but I’m just going to let it go and enjoy it :)
Anyway, you can find the magazine in all good newsagents, or you can download it from the official site (see link above). For my loyal readers, I’ve included a excerpt from the magazine below. I should say though that this is my original (unedited) text, which looks VERY dull without the cool images.
Nanotech is Finally Here – an excerpt!
What’s in your medicine cabinet? Ibuprofen and paracetamol? How about bottles of nanoparticles that can target specific infections and cells in your body… No? Well, that future is much closer than you might think. Engineered nanoparticles will change medicine, and how we diagnose and treat diseases.
Five years ago, gold nanoparticles coated with a polymer were found to penetrate a human cell without causing any damage to it. In 2013, a group from MIT expanded this work and showed that lots of different nanoparticles could be used – it was all do with the coating. Just one molecule thick, the coating is a mixture of hydrophobic (water-repellent) and hydrophilic (water-attracting) components. Cells tend to engulf things in contact with their surface, but this specific combination of chemicals in the coating actually fuses with the lipids (fats and vitamins) in the cell wall, and so, causes no damage. The size of the nanoparticle is also important – it can only pass harmlessly through the cell wall if its diameter falls below the critical size (~ 10 nm). Anything too large will damage the cell. But with the right coating and size, a nanoparticle can pass through the membrane, and once it has, the opening reseals itself. This means that nanoparticles coated in a drug could be inserted into infected cells – direct-to-cell drug delivery, which could be used to treat range of diseases. And at the end of 2013, another MIT group developed nanoparticles coated in insulin that could be delivered orally and absorbed through digestion. This would allow patients to simply take a pill instead of receiving injections.
Nanoparticles can also be used in cancer treatment. One option is to inject a cancer cell with gold nanoparticles. Because gold is an excellent x-ray absorber, if you bombard the cell with x-rays, and, it will heat up and effectively ‘cook’ the cell. A similar technique, using magnetic (iron) nanoparticles and an alternating magnetic field to destroy tumours is also in the animal-trial stage. If successful, the use of nanoparticles in cancer treatment would allow doctors to move away from whole-body treatments, such as chemotherapy, instead focussing on individual cancer cells, destroying them rapidly, but with minimal damage to adjacent healthy tissue. Researchers hope that human trials could begin within a decade.
- Nano-solar cells
Solar cells have gradually entered the domestic market in the last decade, and can be seen on rooftops everywhere, but did you know that typically, they convert less than a fifth of the Sun’s available energy into electricity? Thankfully, recent breakthroughs in nanotechnology are changing the domestic solar cell game.
One of the issues with today’s solar cells is that they are reflective. And any sunlight reflected from the cell cannot be absorbed and converted into electricity. What’s needed is a non-reflective material, a sort of “solar sponge” that can absorb as much light (at different wavelengths) as possible. Ideally, you want this material to also be electrically conductive enough to allow electric charges flow through the cell. Enter III-V semiconductor nanowires – long, thin wires of specific materials (e.g. gallium arsenide, GaAs) that can be easy grown over large areas, like a nanoscale forest! A team from the Australian National University discovered that because the wires are so tightly packed, any light reflected from one will be absorbed by another, and so, most of the light hitting the nanowire forest will be absorbed.
A thin layer of nanowires added to the surface of a domestic solar cell hugely improves its efficiency, and solar cells made with core-shell nanowires (which contain a combination of III-V materials), take this improvement even further by optimising how electric charges flow through the cell. Early results on these solar cells show efficiencies approaching that of the best domestic ones on the market, but using only a fraction of the amount of material, so at a reduced cost.
… So now you’ve had a little preview – I hope you enjoyed it! If you’d like to read the rest of the feature, please head to your nearest newsagents or download the issue through iTunes or Google Play via http://www.science-uncovered.com/ - there are some fantastic articles in this month’s issue, so you’re in for a treat :)