Quantum Dots: A tiny treatment for a massive killer

Drug-resistant bacteria are growing ever more powerful and becoming common killers. Luckily, now a new method of treatment has recently emerged, which could kill up to 92% of these infections.

Quantum Dots for Killing Bacteria

Quantum dots are tiny flecks of fluorescent semiconducting material, only 10-100 atoms in diameter. That translates to about a 20,000th of the width of a human hair! They may be small, but they are very powerful. They are already used as light sources in LCD screens in phones, tablets like the Kindle Fire HDX 7 and HDX 8.9, and televisions from LG, Sony and Samsung.

In this case the quantum dots are made of cadmium telluride. Scientists at the Department of Chemical and Biological Engineering have tested their method on lab-grown cultures and managed to kill 92% of bacteria, and published their findings in the journal Natural Materials.  When the particles are excited by a light source, they absorb the photons and re-emit light with wavelengths depending on their size. The emitted light triggers a chemical reaction which breaks down the bacteria.

The dots are so small that they can be easily absorbed by the invading bacteria, and by controlling the size of the dot, the wavelength can also be controlled. This means that the target bacteria can be destroyed without harming the surrounding cells, which is a common problem in other treatment using metals such as gold or silver.

As the bacteria adapt in response to the treatment, the treatment itself may even be possible to adjust to keep it effective, by changing the wavelength of the light emitted.


Sources:

M. Courtney, S.M. Goodman, J. A. McDaniel, N. E. Madinger, A. Chatterjee, P. Nagpal, Nature Material, 18th January 2016, http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4542.html (accessed 28/03/2016)

BBC Focus Magazine, March 2016, Quantum Dots to Combat Drug-Resistant Bacteria, pg 22

Chris Wood, Gizmag, 20th January 2016, http://www.gizmag.com/light-activated-quantum-dots-antibiotic-resistant-bacteria/41396/ (accessed 28/03/2016)

Chris Smith, BGR, 19th January 2016, Light-activated nanoparticles can kill 90% of antibiotic-resistant bacteria, http://bgr.com/2016/01/19/light-nanoparticles-kill-antibiotic-resistant-bacteria/

 

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