A light-up fluorescence resonance energy transfer magnetic aptamer-sensor for ultra-sensitive lung cancer exosome detection

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Materials for biology and medicine, 2021-03, Vol.9 (1), p.2483-2493
• Main Authors: Zhu, Nanhang, Li, Guohao, Zhou, Juan, Zhang, Yujia, Kang, Ke, Ying, Binwu, Yi, Qiangying, Wu, Yao
• Format: Article
• Language: English
• Subjects: Antigens; Aptamers; Biopsy; Cell adhesion; Cell adhesion & migration; Cell adhesion molecules; Complementary DNA; Energy transfer; Epithelial cells; Epithelium; Exosomes; Fluorescence; Fluorescence resonance energy transfer; Gold; Lung cancer; Magnetic resonance; Nanoparticles; Quantum dots; Resonance; Sensors
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/d1tb00046b

In vitro liquid biopsy based on exosomes offers promising opportunities for fast and reliable detection of lung cancers. In this work, we present a fluorescence resonance energy transfer (FRET) magnetic aptamer-sensor for magnetic enrichment of exosomes with aptamers and detection of cancerous-surface proteins based on a light-up FRET strategy. Fluorescent quantum dots (QDs) and aptamers were introduced onto magnetic nanoparticles and the fluorescence emission turned down when the aptamers were paired with their complementary DNA on the surface of Au nanoparticles. Later, competitive binding of exosomes with the aptamers expelled the Au nanoparticles resulting in an exosome concentration-dependent linear increase of QD fluorescence intensity in a broad exosome concentration range (5 × 10 2 -5 × 10 9 particles per mL). As found in our work, this system behaved ultra-sensitively and the calculated detection limit of this FRET magnetic aptamer-sensor was as low as 13 particles per mL. Furthermore, taking epithelial cancer-specific antigen (epithelial cell adhesion molecule, EpCAM) screening as a typical example, our built FRET magnetic aptamer-sensor allowed a rapid and efficient distinction of all the epithelial cancer cases (7 lung cancers and 5 other cancers) from health volunteers with 100% accuracy. The light-up magnetic aptamer-sensor Fe 3 O 4 @Au for ultra-sensitive lung cancer exosome detection based on fluorescence resonance energy transfer.