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Tuesday, June 20, 2017

Nanofibre optic force transducers with sub-piconewton resolution via near-field plasmon–dielectric interactions

Qian Huang, Joon Lee, Fernando Teran Arce, Ilsun Yoon, Pavimol Angsantikul, Justin Liu, Yuesong Shi, Josh Villanueva, Soracha Thamphiwatana, Xuanyi Ma, Liangfang Zhang, Shaochen Chen, Ratnesh Lal & Donald J. Sirbuly

Ultrasensitive nanomechanical instruments, including the atomic force microscope (AFM) and optical and magnetic tweezers have helped shed new light on the complex mechanical environments of biological processes. However, it is difficult to scale down the size of these instruments due to their feedback mechanisms, which, if overcome, would enable high-density nanomechanical probing inside materials. A variety of molecular force probes including mechanophores, quantum dots, fluorescent pairs and molecular rotors have been designed to measure intracellular stresses; however, fluorescence-based techniques can have short operating times due to photo-instability and it is still challenging to quantify the forces with high spatial and mechanical resolution. Here, we develop a compact nanofibre optic force transducer (NOFT) that utilizes strong near-field plasmon–dielectric interactions to measure local forces with a sensitivity of <200 fN. The NOFT system is tested by monitoring bacterial motion and heart-cell beating as well as detecting infrasound power in solution.

DOI

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