Optical Trapping of a Single Molecule of Length Sub-1 nm in Solution  

作　　者：Biao-Feng Zeng Ran Deng Yu-Ling Zou Chun-An Huo Jing-Yu Wang Wei-Ming Yang Qing-Man Liang Sheng-Jie Qiu Anni Feng Jia Shi Wenjing Hong Zhilin Yang Zhong-Qun Tian Yang Yang 

机构地区：[1]Department of Physics,Pen-Tung Sah Institute of Micro-Nano Science and Technology,State Key Laboratory of Physical Chemistry of Solid Surfaces,IKKEM,Xiamen University,Xiamen 361005

出　　处：《CCS Chemistry》2023年第4期830-840,共11页中国化学会会刊（英文）

基　　金：supported by the National Natural Science Foundation of China(grant nos.T2222002,21973079,22032004,92161118,12174324,21991130,and 21905238);the Ministry of Science and Technology of the People’s Republic of China(grant no.2021YFA1201502);the Natural Science Foundation of Fujian Province(grant no.2021J06008).

摘　　要：Plasmonic optical manipulation has emerged as an affordable alternative to manipulate single chemical and biological molecules in nanoscience.Although the theoretical models of sub-5 nm single-molecule trapping have been considered promising,the experimental strategies remain a challenge due to the Brownian motions and weak optical gradient forces with significantly reduced molecular polarizability.Herein,we address direct trapping and in situ sensing of single molecules with unprecedented size,down to∼5Åin solution,by employing an adjustable plasmonic optical nanogap and single-molecule conductance measurement.The theoretical simulations demonstrate that local fields with a high enhancement factor,over 103,were generated at such small nanogaps,resulting in optical forces as large as several piconewtons to suppress the Brownian motion and trap a molecule of length sub-1 nm.This work demonstrates a strategy for directly manipulating the small molecule units,promising a vast multitude of applications in chemical,biological,and materials sciences at the single-molecule level.

关 键 词：plasmon-enhanced trapping molecular junction mechanically controllable break junction finite-element simulation method single-molecule conductance measurement 

分 类 号：O17[理学—数学]