A nice introduction to nanodevices can be found here:
http://www.cancer.gov/cancertopics/understandingcancer/nanodevices/allpages

Find the answers to some key questions:
1. What Is Nanotechnology?
2. Nanotechnology Plays by Different Rules
3. Designing Nanodevices for Use in the Body
4. Manufacturing Nanodevices
5. Nanodevices Are Small Enough to Enter Cells
6. Nanodevices Can Improve Cancer Detection and Diagnosis
7. Nanodevices Can Improve Sensitivity
8. Nanodevices Can Preserve Patients' Samples
9. Nanodevices Can Make Cancer Tests Faster and More Efficient
10. Cantilevers Can Make Cancer Tests Faster and More Efficient
11. Nanopores
12. Nanotubes - Marking Mutations
13. Nanotubes - Mapping Mutations
14. Quantum Dots
15. Quantum Dots Can Find Cancer Signatures
16. Improving Cancer Treatment
17. Nanoshells
18. Nanoshells as Cancer Therapy
19. Nanodevices as a Link Between Detection, Diagnosis, and Treatment
20. Dendrimers
21. Dendrimers as Cancer Therapy
22. Nanotechnologies in Patient Care