Electrochemical Micro-Immunosensor of Cubic AuPt Dendritic Nanocrystals/Ti₃C₂-MXenes for Exosomes Detection

Exosomes are extracellular vesicles that exist in body circulation as intercellular message transmitters. Although the potential of tumor-derived exosomes for non-invasive cancer diagnosis is promising, the rapid detection and effective capture of exosomes remains challenging. Herein, a portable electrochemical aptasensor of cubic AuPt dendritic nanocrystals (AuPt DNs)/Ti₃C₂ assisted in signal amplification, and aptamer CD63 modified graphene oxide (GO) was immobilized on a screen-printed carbon electrode (SPCE) as the substrate materials for the direct capture and detection of colorectal carcinoma exosomes. Cubic AuPt DNs/Ti₃C₂ was synthesized according to a simple hydrothermal procedure, and the AuPt DNs/Ti₃C₂-Apt hybrid demonstrated an efficient recognition of exosomes. Under optimal conditions, a detection limit of down to 20 exosomes µL^-1 was achieved with the linear range from 100 exosomes μL^-1 to 5.0 × 10⁵ exosomes μL^-1. The proposed immunosensor could be suitable for the analysis of exosomes and has clinical value in the early diagnosis of cancer.