With reference to carbon nanotubes, consider the following statements:
- They can be used as carriers of drugs and antigens in the human body.
- They can be made into artificial blood capillaries for an injured part of the human body.
- They can be used in biochemical sensors.
- Carbon nanotubes are biodegradable.
Which of the statements given above are correct?
[UPSC Civil Services Exam – 2020 Prelims]
(a) 1 and 2 only
(b) 2, 3 and 4 only
(c) 1, 3 and 4 only
(d) 1, 2, 3 and 4
Answer: (d)
Explanation:
- Carbon nanotubes (CNTs) are cylindrical molecules composed of carbon atoms arranged in a hexagonal pattern. They can be formed by rolling up a single graphene sheet (SWCNTs) or multiple sheets (MWCNTs).
- CNTs were once believed to be chemically resistant, but enzymes like peroxidase have been found to facilitate their biodegradation, making option 4 correct.
- NASA has demonstrated the use of CNT arrays as biosensors, making option 3 correct.
- CNTs have a large surface area, enabling them to attach various biological substances and penetrate cell membranes, making them useful for biomedical applications such as artificial implants and drug delivery, hence making statements 1 and 2 correct.