Advances in Exosome Analysis Methods with an Emphasis on Electrochemistry

Exosomes, small extracellular vesicles, are released by various cell types. They are found in bodily fluids, including blood, urine, serum, and saliva, and play essential roles in intercellular communication. Exosomes contain various biomarkers, such as nucleic acids and proteins, that reflect the status of their parent cells. Since they influence tumorigenesis and metastasis in cancer patients, exosomes are excellent noninvasive potential indicators for early cancer detection. Aptamers with specific binding properties have distinct advantages over antibodies, making them effective versatile bioreceptors for the detection of exosome biomarkers. Here, we review various aptamer-based exosome detection approaches based on signaling methods, such as fluorescence, colorimetry, and chemiluminescence, focusing on electrochemical strategies that are easier, cost-effective, and more sensitive than others. Further, we discuss the clinical applications of electrochemical exosome analysis strategies as well as future research directions in this field.