This is my second blog of this month and I am happy to be back again. The reason behind me choosing this topic is that I was fascinate by one of its application to detect cardiac problems beforehand and send the information to the doctors whereby we can reduce the deaths due to cardiac arrests to the maximum! So I was curious to know all about them and wanted to share with you all and any of you can share information about it.
Nanosensors are any biological, chemical or surgery sensory paths used to convey information about nano particles to macroscopic world.
* Presently, widely used nano sensors are working as natural receptors of outside stimulation by sensing nanosized molecules.
* Plants use them for detecting sunlight,
Fishes for sensing the vibrations in water,
Insects for searching their partners etc
* The first nanosensor was built by researchers at Georgia Institute of Technology in 1999 by attaching a particle to carbon nanotube and the difference in frequencies of the nanotube with and without the particle gives the mass of the attached particle.
* Nowadays, carbon nanotubes are used to detect the ionization of gases while titanium nanotubes are used to measure hydrogen concentration in atmosphere.
* The nanosensors have pockets for the attachment of nanoparticles and when that molecule fits into the nanosensor, light is shone on it which then reflects light of different wavelengths and appears in a different color.
a) Top-down lithography:
* Here, a large block of certain material is taken and tailored to the desired shape.
* They are used in microelectromechanical systems as micro sensors and also as nanosensors nowadays.
b) Bottom-up method:
* Here, sensors are made by assembling individual atoms or molecules one by one using atomic force microscopes.
* It is a very difficult process but used as starter molecules for self-assembling sensors.
c) Self-assembly method:-
i) This is like crystallization procedure where a nano structure which was previously created or naturally formed is immersed in its solution and left aside for some time when an irregular structure is formed which would attract more molecules to form a large nanosensor.
ii) Here, all the components assemble by themselves to give the final product. This will enable the scientists to manufacture a large no. of nanosensors in less time with low cost and little energy.
1) High costs about 0.6 - 2.7 billion$.
2) Privacy intrusion
3) Security problems
4) Since medical nanosensors give the future profile about health of an individual along with diagnosis and treatment and there is every chance for the health insurance companies to grant or refuse insurances.
1) Since these nanosensors can identify particular cells or places in the body by sensing the changes in volume, concentration, velocity, pressure, temperature changes etc, they are useful in identifying cancer cells and kill or deliver medicine to them or record development of specific places in the body etc.
2) Some nanosensors use cadmium-selenium quantum dots due to their fluorescence nature which when injected into the body and after finding cancerous cells, they produce fluorescence.
Cadmium-selenium material being toxic to body is now replaced by zincsulphide which is mixed with other metals like manganese and lanthanides. They become fluorescent only after binding to the target cells.
3) They are also used to detect specific DNA molecules so as to recognize genetic problems or the risk of attaining them.
4) Can also record glucose levels in diabetic patients more efficient than the existing ones
5) Used in satellites and other aeronautic machines.
1) When huge constructions like buildings, dams, bridges are built, they need to withstand extreme conditions and stand for a long time. To detect any such problems, scientists have discovered 2 sensors,
a) The 1st type is a microelectromechanical system (MEMS) which checks the temperature and moisture content in the concrete.
b) The 2nd type uses nanotubes which detects small cracks and informs the authorities so that they are prevented from becoming larger ones.
2) Another type of nanosensors developed by our Indian scientists and engineers ay Mumbai IIT detect heart attacks or cardiac problems and send information to the doctors through wireless communication.
This can be inserted into the mobiles they created and costs less, will be available to everyone!
' This blog does not contain any plagiarized material '
Team Leader : Roja Rani