Breaking Through Bead-Supported Assay: Integration of Optical Tweezers Assisted Fluorescence Imaging and Luminescence Confined Upconversion Nanoparticles Triggered Luminescent Resonance Energy Transfer (LRET)

• Published in: Analytical chemistry (Washington) 2019-06, Vol.91 (12), p.7950-7957
• Main Authors: Li, Cheng-Yu, Kang, Ya-Feng, Qi, Chu-Bo, Zheng, Bei, Zheng, Ming-Qiu, Song, Chong-Yang, Guo, Zhen-Zhong, Lin, Yi, Pang, Dai-Wen, Tang, Hong-Wu
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Assaying; Biopsy; Cancer; Chemistry; Energy transfer; Fluorescence; Imaging; Luminescence; Materials selection; miRNA; Nanoparticles; Resonance; Sandwich structures; Upconversion; Viscosity
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.9b01941

Herein, a conceptual approach for significantly enhancing a bead-supported assay is proposed. For the fluorescence imaging technology, optical tweezers are introduced to overcome the fluid viscosity interference and immobilize a single tested bead at the laser focus to guarantee a fairly precise imaging condition. For the selection of fluorescent materials and the signal acquisition means, a type of innovative luminescence confined upconversion nanoparticle with a unique sandwich structure is specially designed to act as an efficient energy donor to trigger the luminescent resonance energy transfer (LRET) process. By further combining the double breakthrough with a molecular beacon model, the newly developed detection strategy allows for achieving a pretty high LRET ratio (≈ 88%) to FAM molecules and offering sound assay performance toward miRNA analysis with a detection limit as low as the sub-fM level, and is capable of well identifying single-base mismatching. Besides, this approach not only is able to accurately qualify the low-abundance targets from as few as 30 cancer cells but also can be employed as a valid cancer early warning tool for performing liquid biopsy.