Scientists in Britain say they have developed a super-sensitive test using nano-particles to spot markers for cancer or the AIDS virus in human blood serum using the naked eye.
As it does not need sophisticated equipment, the test-tube technique should be cheap and simple, making it a boon for disease detection in poor countries, the team wrote in Nature Nanotechnology on Oct. 28.
Researchers used the technology to scan for molecules of p24, a marker for HIV infection, and Prostate Specific Antigen or PSA, an early indicator of prostate cancer. Their method is used to analyze serum, a light-yellow fluid that is extracted from blood by a centifuge and is commonly used in health tests.
“If the result is positive for p24 or PSA, there is a reaction that generates irregular clumps of nanoparticles, which give off a distinctive blue hue in a solution inside the container,” said a statement. The reaction, in response to the presence of antibodies, occurred even at ultra-low concentrations of p24 or PSA.
“If the results are negative, the nanoparticles separate into ball-like shapes, creating a reddish hue. Both reactions can be easily seen by the naked eye.”
Molly Stevens, professor of materials and bioengineering at Imperial College London, says: “It is vital that patients get periodically tested in order to assess the success of retroviral therapies and check for new cases of infection.”
“Unfortunately, the existing gold standard detection methods can be too expensive to be implemented in parts of the world where resources are scarce.
“Our approach affords for improved sensitivity, does not require sophisticated instrumentation and it is 10 times cheaper, which could allow more tests to be performed for better screening of many diseases.”
