Stories tagged Gold nanoparticles

Jan
24
2013

Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.
Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.Courtesy Jeremie63
Chemists from the University of Massachusetts Amherst have developed a way to quickly and accurately detect and identify metastatic cancer cells in living tissue, in much the same way that your nose can detect and identify certain odors.

The smell of a rose, for example, is a unique pattern of molecules, which activates a certain set of receptors in your nose. When these specific receptors are triggered, your brain immediately recognizes it as a rose.

Similarly, each type of cancer has a unique pattern to the proteins that make up its cells. The Amherst chemists just needed a "nose" to recognize these patterns. What they came up with was an array of gold nanoparticle sensors, coupled with green fluorescent proteins (GFP). The researchers took healthy tissue and tumor samples from mice, and trained the nanoparticle-GFP sensors to recognize the bad cells, and for the GFP to fluoresce in the presence of metastatic tissues.

This method is really sensitive to subtle differences, it's quick (can detect cancer cells within minutes), it can differentiate between types of cancers, and is minimally invasive. The researchers haven't tested this method on human tissue samples yet, but it holds some exciting potential.

Jan
26
2012

What’s the quietest thing you can hear? A pin drop? The pitter-patter of a mouse? Applause for my clever title? Now imagine if you could hear bacteria moving or cells dividing!*

To hear these sounds, you won’t use your boring old ears. Instead, you’ll be able to hear them with your eyes! Well, actually, you won’t even be able to use your eyes. You’ll need to use a little math…these sounds are really small, folks.

Let’s take a step back for a second. Hearing is simply the detection of vibrations by tiny bones (and hairs) in your ear. Those vibrations are then sent through a sensory nerve (the cochlear nerve) to the brain’s cerebral cortex, where it is translated and interpreted. Easy, right? However, our ears can only detect sounds as quiet as 0 decibels (dB), which is near total silence. (For reference, a whisper is about 15 dB, normal speech is about 60 dB, and a jet engine is 120 dB) To me, “near total silence” is pretty good, but scientists have found a way to detect sound levels as low as -60 dB. This is about a million times more sensitive than the hearing threshold of the human ear! Nanoear Prototype #1: Scientists scrapped this version.  It just ended up pooping all over.
Nanoear Prototype #1: Scientists scrapped this version. It just ended up pooping all over.Courtesy DanCentury

Researchers at the Nanosystems Initiative Munich (NIM) used gold nanoparticles, laser beams, microscopes, and the Fourier Transformation (read: math) to create a nanoear]. The way it works is to suspend a single gold nanoparticle with a red laser beam (an optical trap), create a small sound, then watch the gold nanoparticle oscillate (using a microscope, of course). The scientists tested their newfangled nanoear in two steps: In their first trial, they used a needle as the sound source, and they were able to actually see the nanoparticle vibrate. In the second step, the researchers used heat as their sound source- I know, crazy! On the same surface as the red-laser-suspended nanoparticle, they fixed a small number of gold particles and heated them with a green laser. The very weak sound waves caused vibrations in the nanoparticle that were imperceptible to the eye, but when the scientists applied the Fourier Transformation, they were able to show that the nanoparticle was, in fact, oscillating, and thus confirming the high sensitivity of the nanoear. This method of "hearing" will allow us to learn about the teeny-tiny movements of cells and their organelles, for example, or any other microscopic object.

I can see a modern re-make of the classic tale A Christmas Carol, by Charles Dickens:
Fred: Let’s play similes!
Fred’s wife: Oh, I do so love this game!
Fred: Ok, let’s start with, quiet as…
Fred’s wife: Quiet as a bacterial flagellum!!
Fred: Right!
[Party guests buzz with excited agreement. Fred’s wife nailed it.]

*Cells dividing must surely make the same sound as blowing bubbles into water with a straw. They probably won’t even have to test that.

Researchers have developed several ways to potentially mass-produce silk without moths or spiders. The silk can be a hard solid, gel, liquid, sponge, or fiber, is stronger than kevlar, non-toxic, and biodegradable. It's perfectly clear and can be used to create plastics, optical sensors, medicine delivery capsules implanted inside the body--the applications are pretty huge and pretty green.

There's already a silk tissue scaffold on the market that can be used to regenerate ligaments or other damaged tissue--the scaffold is implanted into the body in place of damaged tissue, and as new tissue grows around it, the silk slowly breaks down into amino acids and is reused by the body. How cool is that?!

Diamonds and Silver and Gold. OH MY!
Diamonds and Silver and Gold. OH MY!Courtesy Calliopejen

Even nanoscience can't resist the bling. Scientists are incorporating gold, silver and diamonds into all kinds of nanotechnology.

"The most marketable bling technology might be wrapped into something that you take with you everywhere. It could transform your favourite gadgets, including cellphones and music players - by incorporating them into your clothing. "Rather than carrying your iPod, the whole electronic system could be embedded in your jacket," says Jennifer Lewis, a materials scientist at the University of Illinois at Urbana-Champaign."

Check out this article from New Scientist to learn more.
http://www.newscientist.com/article/mg20627571.200-blingtronics-diamonds...