Nanosensors to Measure Cancer Biomarkers

The team used nanowire sensors to detect and measure concentrations of two specific biomarkers: one for prostate cancer and the other for breast cancer. To overcome the challenge of whole blood detection, the researchers developed a novel device that acts as a filter, catching the biomarkers—in this case, antigens specific to prostate and breast cancer—on a chip while washing away the rest of the blood. Creating a buildup of the antigens on the chip allows for detection down to extremely small concentrations, on the order of picogrammes per milliliter, with ten percent accuracy. This is the equivalent of being able to detect the concentration of a single grain of salt dissolved in a large swimming pool.

Until now, detection methods have only been able to determine whether or not a certain biomarker is present in the blood at sufficiently high concentrations for the detection equipment to give reliable estimates of its presence. "This new method is much more precise in reading out concentrations, and is much less dependent on the individual operator's interpretation," Tarek Fahmy, one of the lead researchers, said.

In addition to relying on somewhat subjective interpretations, current tests are also labour intensive. They involve taking a blood sample, sending it to a lab, using a centrifuge to separate the different components, isolating the plasma and putting it through an hours-long chemical analysis. The whole process takes several days. In comparison, the new device is able to read out biomarker concentrations in a just a few minutes.

"Doctors could have these small, portable devices in their offices and get nearly instant readings," Fahmy said. "They could also carry them into the field and test patients on site." The new device could also be used to test for a wide range of biomarkers at the same time, from ovarian cancer to cardiovascular disease, according to the researchers.; Source: Yale University