用于分子和细胞水平机械探测的纳米纤维光学力传感器。

Nanoscale fiber-optic force sensors for mechanical probing at the molecular and cellular level.

机构信息

Materials Science and Engineering, University of California, San Diego, San Diego, CA, USA.

Department of Nanoengineering, University of California, San Diego, San Diego, CA, USA.

出版信息

Nat Protoc. 2018 Nov;13(11):2714-2739. doi: 10.1038/s41596-018-0059-9.

DOI:10.1038/s41596-018-0059-9

PMID:30367169

Abstract

There is an ongoing need to develop ultrasensitive nanomechanical instrumentation that has high spatial and force resolution, as well as an ability to operate in various biological environments. Here, we present a compact nanofiber optic force transducer (NOFT) with sub-piconewton force sensitivity and a nanoscale footprint that paves the way to the probing of complex mechanical phenomena inside biomolecular systems. The NOFT platform comprises a SnO nanofiber optic equipped with a thin, compressible polymer cladding layer studded with plasmonic nanoparticles (NPs). This combination allows angstrom-level movements of the NPs to be quantified by tracking the optical scattering of the NPs as they interact with the near-field of the fiber. The distance-dependent optical signals can be converted to force once the mechanical properties of the compressible cladding are fully characterized. In this protocol, the details of the synthesis, characterization, and calibration of the NOFT system are described. The overall protocol, from the synthesis of the nanofiber optic devices to acquisition of nanomechanical data, takes ~72 h.

摘要

目前，人们一直需要开发具有高空间和力分辨率的超灵敏纳米机械仪器，并且能够在各种生物环境中运行。在这里，我们提出了一种紧凑的纳米光纤力传感器（NOFT），具有亚皮牛顿的力灵敏度和纳米级的足迹，为探测生物分子系统内部复杂的机械现象铺平了道路。NOFT 平台由 SnO 纳米光纤组成，配备了一层薄的、可压缩的聚合物包层，上面镶嵌着等离子体纳米颗粒（NPs）。这种组合允许通过跟踪 NPs 的光学散射来量化它们与光纤近场相互作用时的埃级运动，因为 NPs 与光纤近场相互作用。一旦完全表征了可压缩包层的机械性能，就可以将距离相关的光学信号转换为力。在本方案中，描述了 NOFT 系统的合成、表征和校准的详细信息。从纳米光纤器件的合成到纳米力学数据的获取，整个方案大约需要 72 小时。