Q1.
When reference to carbon nanotubes, consider the following statements: 1. They can be used as carriers of drugs and antigens in the human body. 2. They can be made into artificial blood capillaries for an injured part of human body. 3. They can be used in biochemical sensors. 4. Carbon nanotubes are biodegradable. Which of the statements given above are correct?
Answer
D
Explanation
Carbon nanotubes (CNTs) are cylindrical large molecules consisting of a hexagonal arrangement of hybridized carbon atoms, which may by formed by rolling up a single sheet of graphene (single-walled carbon nanotubes, SWCNTs) or by rolling up multiple sheets of graphene (multiwalled carbon nanotubes, MWCNTs). Hence structurally, carbon nanotubes (CNTs) can be viewed as wrapped from graphene sheets. Carbon nanotubes were once considered to be resistant to chemical damage due to their rigid and perfect chemical structure, which rendered them immune to biodegradation. However, enzymes like peroxidase were found to play an important role in the process of biodegradation of carbon nanotubes. Hence option 4 is correct. NASA has demonstrated the use of carbon nanotube arrays as biosensors. Hence option 3 is correct. Carbon nanotubes (CNTs) are characterized by unique chemical and biological properties. CNTs