Biosensor Technology Could Pave Way for POC Diagnosis of Cancer, Pathogens, and Other Diseases

Biomarkers for some diseases and infections are only present in samples in very small amounts, which in turn impose the challenge to develop extremely sensitive detection techniques. While increasing the surface area of the biosensor can increase the sensitivity of the diagnostic device, these surfaces tend to be quickly clogged and contaminated, rendering them unusable. To address this issue, researchers have developed a biosensor using a method to generate nanostructured and nanoporous surfaces. This combined strategy not only provides the sensor with an unprecedented sensitivity but also makes it resistant to fouling by proteins. While previously there has been no known method to reliably create electrodes using such nanostructured and nanoporous substrates, the researchers have reported a simple method to generate such materials.

The mechanism developed by researchers at the Institute for Basic Science (Ulsan, South Korea) is based on the application of electric pulses to a flat gold surface in the presence of sodium chloride and a surfactant that can form micelles in solution. These electric pulses drive a preferent reaction to etch and redeposit gold from the surface and, in turn, grow nanostructures and form the nanopores. The use of surfactant in the form of micelles is essential to the success of this strategy since it prevents the material that is being etched from diffusing away during the process, so it can be redeposited.

The formation of these nanostructures yielded a large surface area which was beneficial for increasing the sensitivity of the assays, whereas the formation of nanopore substrates was ideal to prevent contamination from the biological samples. Both the nanostructures and the nanopores' combined benefits were key to the success of this strategy, which could be applied for the direct analysis of clinical plasma samples. The researchers further demonstrated this new technology by building a biosensor for the detection of prostate cancer. The electrode was sensitive enough to discriminate between a group of prostate cancer and healthy donors using only a tiny amount of blood plasma or urine samples. No dilution or preprocessing steps were used, which means that the technology could easily be used for the point-of-care diagnosis of cancer.

“We believe that this technology is essential for the future development of point-of-care devices and diagnostic tests that work with biological samples,” said Professor Cho Yoon-Kyoung at the Center for Soft and Living Matter within the Institute for Basic Science (IBS), who led the study. “The capability to detect low concentrations of relevant biomarkers with robust performance opens a door to possibilities in the field of diagnostics for cancer, pathogens, and other diseases.”

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