In this individual vesicle approach, the EV membrane is decorated with laser excitation-detected fluorescent tags for a report of the total EV number, while selected antibody (anti-HER2, anti-EpCAM, or anti-CD24)-conjugated gold nanoparticles (AuNPs) are employed as a detection probe for breast cancer-associated EVs. Here, EPCAM is linked to breast carcinoma.