A Golden Diagnostic Development

A novel test that costs less than US $1 and yields results in minutes is shown to be more sensitive and more exact than PSA (prostate specific antigen) screening – the prevailing standard test for early-stage prostate cancer. Gold nanoparticles are known for their extraordinary efficiency at absorbing and scattering light. Qun Ho, from University of Central Florida (Florida, USA), and colleagues developed a technique known as nanoparticle-enabled dynamic light scattering assay (NanoDLSay) to measure the size of the particles by analyzing the light they throw off. That size reveals whether a patient has prostate cancer and how advanced it may be. When a few drops of blood serum from a finger prick are mixed with the gold nanoparticles, certain cancer biomarkers cling to the surface of the tiny particles, increasing their size and causing them to clump together. The team conducted two pilot studies on blood serum samples collected at Florida Hospital and obtained from Prostate Cancer Biorespository Network (PCBN), revealing that the test has a 90-95% specificity and 50% sensitivity in detecting early stage prostate cancer. Commenting that "this [represents] a significant improvement over the current PSA test, "the study authors report that: "The increased amount of human IgG found in the protein corona is believed to be associated with the autoantibiodies produced in cancer patients as part of the immunodefense against tumor." The investigators also submit that: "This new blood test is simple, low cost, requires only a few drops of blood sample, and the results are obtained within minutes...The test is well suited for screening purpose."