Gold nanoparticles are used in a variety of new "sniffers" for cancer and other diseases. As cancerous cells grow, genes and proteins within cells change, and this process emits volatile organic compounds that can be detected--this is why some dogs can be trained to "smell" cancer. Nanoparticles can smell it, too, and in tiny concentrations. Israeli researchers
a couple of years ago reported new gold nanoparticle sensors that can tell not only whether a person has cancer, but which kind--lung, breast, prostate or colon cancer.
The benefit of such a system is its early-warning capability. Doctors could administer a simple breath test, and be able to tell whether a patient has the beginning stages of cancer--well before any tumors would show up on an X-ray or mammogram.
And it's not just cancer patients who can benefit. Chad Mirkin of Northwestern University is developing nanoparticles that can diagnose and treat disease, tracking cancer at earlier stages and even determining whether hospital patients have infections. If someone needs emergency surgery, it may not always be possible for doctors to obtain the person's medical history, which leaves plenty of unanswered and potentially dangerous questions--does this person have diabetes? Is she at risk for blood clots? Nanoparticles can be used to answer these and other questions. Mirkin points to a relatively new test for sepsis, or blood infection, which has great promise for treating patients better and saving money.
Sepsis can be fatal if not treated quickly and thoroughly, but tests to determine a person's infection level can take three days to complete--meanwhile, the patient is pumped full of antibiotics. But gold nanoparticles functionalized with DNA can identify whether or not someone has sepsis, and which bug is running rampant through his bloodstream, Mirkin said. "It's the difference between a $20 test and hundreds of thousands of dollars in antibiotics," he said.