Michigan State University scientists have developed a new Raman imaging system that can effectively distinguish between cancerous and healthy cells by detecting the extremely weak signals emitted by nanoparticles attached to tumors, which is expected to promote early diagnosis of cancer. The relevant results were published in the latest issue of the journal Optics. This system is designed specifically for capturing weak signals from surface enhanced Raman scattering (SERS) nanoparticles. These nanoparticles can specifically bind to tumor markers, and the system automatically identifies areas that may contain tumor tissue by reading their Raman signals. The new system can quickly distinguish between cancer cells and healthy cells, with significantly improved sensitivity, and can detect Raman signals with intensity only 1/4 of similar commercial systems. Although it cannot temporarily replace pathological methods, it can serve as a rapid screening tool, accelerate the diagnostic process, achieve earlier detection of tumors, and reduce diagnostic delays. The sensitivity improvement of this system is due to the combination of an adjustable wavelength scanning source laser and an ultra sensitive detector - a superconducting nanowire single photon detector (SNSPD). SNSPD uses superconducting nanowires capable of detecting single photons, which can capture extremely weak light signals at high speed under low background noise. SERS nanoparticles coated with hyaluronic acid can bind to surface proteins of tumor cells. Preliminary experiments show that the system sensitivity can reach the femtosecond level. Subsequently, the team tested the system in cultured breast cancer cells, mouse tumor tissue and healthy tissue samples. The results showed that the SERS signals in tumor samples were highly concentrated, while only very low background signals were detected in healthy tissue, reflecting the high sensitivity and reliable identification ability of the system. In addition, by replacing targeting molecules, this method can also be extended to other types of cancer. (New Society)