Surface enhanced Raman spectroscopy‐based immunoassay detection of tumor‐derived extracellular vesicles to differentiate pancreatic cancers from chronic pancreatitis

Abstract Pancreatic cancer (PC) is an aggressive malignancy with an exceptionally high mortality rate because it lacks effective early diagnosis methods. To improve the ability to diagnose PC, the identification of biomarkers that can differentiate PC patients from both normal controls (NC) and those with chronic pancreatitis (CP) is vital. This study demonstrates the detection of extracellular vesicles (EVs) as an excellent resource of diagnostic biomarkers in serum samples from NC individuals, and CP and PC patients using a surface enhanced Raman spectroscopy (SERS)‐based immunoassay technique. The assay uses the Au‐CD81‐EVs‐EphA2‐Au complex to capture PC tumor‐derived EVs specifically and produces highly localized regions of intense field enhancement (hot spots) concurrently. Applying a machine learning algorithm to the analysis of the expression level of EVs biomarkers in PC, CP, and NC individuals, the sensitivity and specificity were measured as 0.95 and 0.96, respectively. Measuring PC tumor‐derived EVs' expression levels in serum of PC patients, CP patients, and NC individuals suggests the great potential of using this biomarker to differentiate pancreatic cancers from chronic pancreatitis.