Exosomes as potential biomarkers in liquid biopsy hold great potential for early cancer diagnosis and monitoring of highly metastatic cancer cells. Recently, a group of researchers proposed a novel electrochemical biosensor for sensitive identification and detection of target exosomes. The biosensor, based on 2D MXene membranes decorated with hierarchical Au nanoarrays, shows satisfactory reproducibility, wide linear range, and high sensitivity for exosome sensing.