A new blood test using a light sensor can detect extremely small amounts of cancer biomarkers in the blood, enabling earlier and easier cancer detection. The technology combines DNA nanotechnology, CRISPR and quantum dots that generate a clear signal from just a few molecules. The test was successfully validated on serum samples from patients with lung cancer. This method represents an advance in the earlier detection of cancer compared to traditional imaging methods. Researchers expect the technology could power portable blood tests for cancer and other diseases in the future. Such tests could improve the possibilities of early diagnosis and treatment of various diseases.