Recent Advances in Fluorescence Resonance Energy Transfer (FRET) Biosensors for Exosomes

Cancer is a significant global health challenge, where early diagnosis is crucial for enhancing patient survival and mitigating the treatment burden on patients. Exosomes are extracellular vesicles released through the fusion of multivesicular bodies with cell membranes, carrying disease-associated information from donor cells. This makes exosomes a key biomarker in liquid biopsy analysis, particularly for early cancer detection. Developing cost-effective, straightforward, and sensitive exosome biosensing technologies is of significant practical importance. To date, a large number of fluorescence-based exosome biosensors have relied on the Fluorescence Resonance Energy Transfer (FRET) principle. This review introduces the basic background of the field and the principle of FRET-based exosome sensors, followed by a systematic summary of their progress categorized by different transduction elements or mechanisms. Finally, this work discusses the current challenges in the field and proposes potential solutions and future prospects, aiming to encourage and inspire the development of new approaches for advanced FRET exosome biosensors.