:: Striped Nanoparticles for Drug Delivery ::
Although the use of nanoparticles for drug delivery is nothing new, but how to synthesize nanoparticles to interact properly with cells remain an area of active research. MIT (Massachusetts Institute of Technology) recently discovered that nanoparticles of striped morphology were able to penetrate cell membranes without damaging it or killing the cell itself. Amazing! The trick is to coat gold nanoparticles with alternating bands of 2 different types of materials. Usually when cell membranes encountered foreign objects, e.g. nanoparticles, they'll engulf it into the cell, digest & then excrete it from the cell. However in this case, by mimicking the properties of cell membrane, the nanoparticles are able to bypass the cell defense system to successfully deliver its cargo, in this case, the fluorescent imaging agents into the cell (as shown in background of image).
:: Nanosensors for Detection of Deadly Gases ::
(Source of image : http://web.mit.edu/newsoffice/2008/nanotube-0605.html)
Carbon nanotubes are interesting materials with novel electronic properties. MIT has created a carbon nanotube-based nanosensor which is extremely sensitive, low cost & low power consumption. With 25-ppt sensitivity, it's the most sensitive electronic gas detector to date. Sarin, mustard & other nerve agents can be detected. Sarin was the toxic gas which killed 12 people in the 1995 terrorist attack on the Tokyo subway, with lethal dose in ppm range & effects surfaced after 10 mins. In addition, with power consumption of only 0.0003 watts, it can run for very long time with a regular battery.
The principle behind this is that when different gases bind to nanotubes, different changes in electrical conductivity are generated. Hence, the identity of the gases can be established. But how to make the binding reversible in order to detect a series of different gases? The MIT team coated a special type of material onto the nanotubes, which allows the gas molecules to detach shortly after binding. But then how to separate the different gases for detection? The team etched a mini GC column onto the silicon chip which rapidly separates the gases before feeding them into nanotubes. Oh my God, amazing!
Reference : http://web.mit.edu/newsoffice/2008/nanotube-0605.html
[ Reflection ]
It's heartening to see that some of our FYP projects are related to these new discoveries, e.g. layer-by-layer system by VC/TT & nanostructured semiconductor gas sensors by TT/CY. It's weird why VC keep discouraging students not to do his projects, saying that it's useless & impractical. Well, they have the foundation for creating advanced technologies, unfortunately the atmosphere is just not there yet. I do feel that NTU can be the MIT of Asia, provided it can cultivate its own kind of atmosphere which stimulates excitement for discovery among ALL of its academic community, not just for the elites of academic results.
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