Light-Driven Nano-oscillators for Label-Free Single-Molecule Monitoring of MicroRNA

• Published in: Nano letters Vol. 18; no. 6; pp. 3759 - 3765
• Main Authors: Chen, Zixuan, Peng, Yujiao, Cao, Yue, Wang, Hui, Zhang, Jian-Rong, Chen, Hong-Yuan, Zhu, Jun-Jie
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 13.06.2018
• Subjects: Equipment Design; Gold - chemistry; Light; Metal Nanoparticles - chemistry; MicroRNAs - analysis; Nucleic Acid Hybridization - methods; Optical Imaging - instrumentation; Optical Imaging - methods; Surface Plasmon Resonance - instrumentation; Surface Plasmon Resonance - methods; nano-oscillators; single-molecule detection; mechanoresponsive polymer; microRNA; Surface plasmon resonance; dark-field microscopy
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.8b00993

Here, we present a mapping tool based on individual light-driven nano-oscillators for label-free single-molecule monitoring of microRNA. This design uses microRNA as a single-molecule damper for nano-oscillators by forming a rigid dual-strand structure in the gap between nano-oscillators and the immobilized surface. The ultrasensitive detection is attributed to comparable dimensions of the gap and microRNA. A developed surface plasmon-coupled scattering imaging technology enables us to directly measure the real-time gap distance vibration of multiple nano-oscillators with high accuracy and fast dynamics. High-level and low-level states of the oscillation amplitude indicate melting and hybridization statuses of microRNA. Lifetimes of two states reveal that the hybridization rate of microRNA is determined by the three-dimensional diffusion. This imaging technique contributes application potentials in a single-molecule detection and nanomechanics study.