When it comes to cancer detection, size matters. Traditional diagnostic imaging cannot detect tumors smaller than a certain size, causing missed opportunities for early detection and treatment. Circulating tumor exosomes are especially small cancer biomarkers and easy to miss. These nanovesicles are composed of molecules that reflect the parental cells. But, because they are tiny (~30-150 nm in diameter) and complex, the precise detection of exosome-carried biomarkers with molecular specificity has been elusive, until now. Wei-Chuan Shih, PhD, Professor of Electrical and Computer Engineering at the University of Houston Cullen College of Engineering, and colleagues report new findings in this area online on September 7, 2021 in IEEE Sensors journal.