Fabrication of bio-electronic nanosensors using the theory of functionalization of metal nanotube hybridization

Fabrication of bio-electronic nanosensors using the theory of  functionalization of  metal nanotube hybridization (PhD in nano-microelectronics) 

Researcher  and author: Dr.   (   Afshin Rashid)

Note:  Several  forms about ways  to build nano-bio-electronic sensors using the  functionalization  hybridization metallic nanotubes   are  there. First of all, most nanotubes become functional  and as a result the electronic structure of  SWCNTs is defective. Second,  due to the strong reaction, it is difficult to purify the product from  amorphous carbon. Most importantly, there is  no covalent reaction after  which the nanotube (m, n) can be purified uniformly  .

These reactions sometimes destroy the nanotube walls and lead to the formation of amorphous carbon or graphite layer structures. By hydrogenating single-walled nanotubes, the semiconductor nature of SWCNTs increases at room temperature. Strong plasma or high temperature reaction engraves the wall of metal nanotubes. That semiconductor SWCNTs are not damaged. Therefore, it is very important to control the reaction conditions. In nanotubes, reaction with methane plasma  removes metal SWCNTs without degrading  semiconductor SWCNTs. In the  method of using soft nanomolecular hydrogen plasma  in which hydrogen plasma is  used to convert metal SWCNTs to  semiconductor SWCNTs, in  which case the nanotube walls are  not destroyed or engraved. These reactions, which take place in the gas phase,  result in the construction of large-scale TFTS and  FETS with semiconductor nanotubes,  which is crucial for the commercialization of high-efficiency nanotube-based equipment  . By selecting the appropriate reactant gases, this  method can also be used for selective reaction with  semiconductor nanotubes. By reacting SWCNTs SO3 as  under neutral gas in the presence of gas; Reagent gas inside the furnace at 400 ° C, semiconductor nanotubes preferably  react with gas  . The nanotubes are then heated to a temperature of 900 °  C to recover metal  defects with structural defects. This process is  a simple way to enrich the nanotube sample from Nanotubes are metal. Mass production of metal nanotubes  can be done by more precise control of reaction conditions  and ultimately increase the scale of  production of its uses, including conductive films and  transparent electrodes.

In general, based on the reaction rate, electrochemical  covalent selectivity of metal nanotubes can  be divided into two categories: 

1.  First, the nanotube metal to a semiconductor,  turn that off of the type of metal  used and end the nanotube metal is  the first reaction along with the establishment of the electron and the  loss of symmetry and a dash of energy  at the Fermi level nanotube metal Creates. 

2.  The second reaction conjugate all systems into a  series of smaller aromatic compounds through the  open CC bonds in the structure of nanotubes  makes. The end result of both cases  is the acquisition of semiconductor  nanotubes that are suitable for the manufacture of nanoelectronic equipment  .

3- In selective covalent reactions, the concentration of the  reactant is always important. And when the concentration of the reactant is high  , both types of nanotubes are affected by the reaction  . In the case of FETS, for example, increasing the  reactant concentration reduces the Off current  , resulting in an off / On ratio of more than  105. On the other hand, the strong reaction  reduces mobility, which is another important parameter  for electronic equipment. Therefore, there must be a  balance between the rate of reaction progress and the final efficiency  of the equipment.

Conclusion : 

Several  forms about ways to  build nano-bio-electronic sensors using the  functionalization  hybridization metallic nanotubes   are  there. First of all, most nanotubes become functional  and as a result the electronic structure of  SWCNTs is defective. Second,  due to the strong reaction, it is difficult to purify the product from  amorphous carbon. Most importantly, there is  no covalent reaction after  which the nanotube (m, n) can be purified uniformly  .

Researcher  and author: Dr.   (   Afshin Rashid)

PhD in Nano-Microelectronics