Researchers from a multi-institutional group have developed a label-free chip-based sensor to detect very low levels of a cancer biomarker in urine. This exciting development may one day help catch cancer earlier, perhaps during regular screenings, leading to better outcomes.
Current methods of cancer biomarker detection are often expensive and challenging, requiring invasive biopsies and specialized tools and laboratories. Clinical research has shown that the protein S100A4 is associated with human tumor development. To address the challenge of cancer detection, the researchers developed an inexpensive method to detect this protein in urine, paving the way for non-invasive and low-cost cancer detection solution.
The technology relies on an optical microchip into which a small volume of a patient’s urine sample is loaded. The microchip contains probes which bind to the S100A4 protein biomarker. An on-chip laser illuminates the sample, and the biomarker and light interact, causing a change in the frequency of the laser light. This change in frequency is measured and an appropriate value indicates the presence of the S100A4 cancer biomarker.
“The new technology we developed paves the way to faster and ultra-sensitive detection of panels of biomarkers that will permit doctors to make timely decisions that improve personalized diagnosis and treatment of medical conditions including cancer,” said Sonia M. Garcia-Blanco, the research team leader. “Although sensors based on monitoring frequency shifts of lasers already exist, they often come in geometries that are not easily integrated on small, disposable photonic chips. Aluminum oxide can easily be fabricated monolithically on-chip and is compatible with standard electronic fabrication procedures. This means that the sensors can be produced on a large, industrial scale.”
The publication in Optics Letters: Al2O3:Yb3+
integrated microdisk laser label-free biosensor