A multifunctional biomimetic interface biosensor for one-step amplified detection of tumor-derived exosomal miRNA

Tumor-derived exosomal miRNAs serve as crucial biomarkers for clinical diagnosis and disease treatment monitoring. However, the need to lyse exosomes and extract miRNAs renders most methods expensive, laborious, and time-consuming. The simple, rapid, and sensitive analysis of exosomal miRNA still poses a significant challenge. Herein, we present a multifunctional biomimetic interface biosensor (MBIB) for exosome capture, miRNA release and amplified detection in one step. Catalytical hairpin assembly (CHA) probes functionalized MCF-7 cell membrane was firstly coated onto the glass substrate to fabricate the MBIB. Due to the homologous recognition ability, the MBIB could specifically capture MCF-7 cell-derived exosomes from samples and then release miRNA through membrane fusion. Finally, the released miRNA could be detected by the CHA probes on the cell membrane. Owing to the fluidity of the cell membrane, the CHA probes could collide effectively, resulting in an enhanced signal. The developed biosensor exhibited high sensitivity, reproducibility and stability. It has been successfully applied to the real samples and could accurately distinguish the tumor-bearing mice and healthy mice, showing great potential in clinical application.