An integrated magneto-fluorescent nanosensor for rapid and sensitive detection of tumor-derived exosomes

• Published in: Sensors and actuators. B, Chemical Chemical, 2023-01, Vol.374, p.132792, Article 132792
• Main Authors: Luo, Shihua, Wu, Yuan, Pan, Weilun, Zhong, Guangzhi, Situ, Bo, Li, Bo, Ye, Xinyi, Jiang, Xiujuan, Li, Wenbin, Zhang, Ye, Zheng, Lei, Wang, Qian
• Format: Article
• Language: English
• Subjects: Amplification; Biomarkers; Catalytic converters; Catalytic hairpin assembly; CRISPR-Cas12a; DNA tetrahedral lipid probe; Exosomal PD-L1; Fluorescence; Fluorescent nanosensor; Lipids; Magnetic separation; Nanosensors; Proteins; Reagents; Tumors
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2022.132792

Cancer released-exosomes containing specific surface proteins have high value in tumor diagnosis and are considered a novel liquid biopsy biomarker. However, the development of rapid and sensitive quantitative methods for their determination remains challenging because of the low abundance of exosome surface protein. Herein, we developed a new platform using an integrated magneto-fluorescent exosome (iMFEX) nanosensor for rapid and sensitive detection of exosomes derived from cancers. First, magnetic beads were coated with a DNA tetrahedral lipid probe to efficiently capture exosomes. The rationally designed bifunctional aptamer specifically recognized exosomal PD-L1 protein and initiated catalytic hairpin assembly, thereby converting protein signals into H1/H2 duplexes. Finally, the H1/H2 duplexes activated the Cas12a protein trans-cleavage reporter FAM-TTATT-BHQ1 for fluorescence signal amplification. By integrating magnetic separation and fluorescence signal amplification, the proposed iMFEX nanosensor exhibited excellent specificity and sensitivity toward PD-L1 positive exosomes, ranging from 2.86 × 103 to 2.86 × 107 particles/μL, with a detection limit of 1.71 × 103 particles/μL. Using the iMFEX nanosensor, we were able to effectively track the dynamic changes in exosomal PD-L1 expression induced by reagents and to distinguish patients with non-small cell lung cancer from healthy individuals, thus demonstrating the platform’s potential for clinical application. •The capture of exosomes with MB@DTLP requires only 15 min, and bulky and expensive instruments are unnecessary.•Aptamer mediated CHA-CRISPR/Cas12a cascade amplification strategy achieves sensitive detection of non-nucleic acid targets.•The iMFEX nanosensor can be easily applied to detect other exosomal protein markers by simply changing the aptamer sequence.•This proposed method can precisely measure NSCLC, which correlated excellently with immunohistochemical results.