With 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?

Carbon nanotubes (CNTs) are cylindrical molecules composed of a hexagonal arrangement of hybridized carbon atoms.

They can be single-walled (SWCNTs) or multi-walled (MWCNTs), essentially graphene sheets rolled up.

CNTs possess unique chemical and biological properties, including a large surface area for attaching biological substances and the ability to penetrate cell membranes and capillaries. This makes them suitable for:

• Drug and antigen delivery within the human body.
• Creating artificial blood capillaries for tissue replacement.
• Use in biochemical sensors.

Initially considered resistant to biodegradation, it has been discovered that enzymes like peroxidase can facilitate the biodegradation of carbon nanotubes.

Therefore, all statements are correct.