Nanotechnology's Prescription for Health Care

Nanotechnology has the potential to improve patients' chances of recovery through early detection of medical conditions. An early diagnosis would give doctors a chance to battle cancer before it has spread throughout the body or treat a disease before it has caused irreversible damage.

Current technology cannot detect cancer cells, for example, until the tumor has grown to a significant size. The use of quantum dots could enable detection almost at the onset of the growth of cancerous cells. Scientists can affix specific molecules to quantum dots. For cancer research, they choose a molecule that will bind to a specific type of tumor cell. When injected into the bloodstream, the molecules attach themselves—and the quantum dots—to the cells of the tumor. The quantum dots are then charged with energy by illumination from a light source. The quantum dots produce a glow that can be scanned and photographed.

Different quantum dots emit different wavelengths of light. Conceivably, a patient could be injected with a solution containing several different types of quantum dots, each designed to adhere to a certain type of malignant cell. The doctor could then scan for various types of cancer with a single test. The different colors of light would signify the location and type of malignancies.

Quantum dots are just one type of nanoscale probe. Researchers are investigating many possible nanoparticle probes that will track conditions at a cellular and molecular level.

Another potential breakthrough for diagnosis takes miniaturization to the nanoscale level. It is called “lab-on-a-chip” (LOC), or biochip. A single microchip moves a liquid sample through nanoscale channels and past sensors that would screen it for the presence of substances such as viruses or chemical agents. The lab-on-a-chip would be automated, portable, and nearly instantaneous. Chips called microarrays, and the further miniaturized nanoarrays, are already being used for DNA analysis.