摘要
面向生物粒子操控方法的研究,在生物医学和生命科学等领域具有重要意义。光镊操控具有无接触与高精度的特点,已被广泛应用于多个领域的研究中。然而,传统光镊的光热效应以及衍射极限都制约着光镊在生物医学领域的更广泛应用和发展。近十年来,研究者们将光热效应化劣势为优势,利用光与热的耦合效应实现了多种粒子的精确捕获及操控,即光致温度场光镊(OTFT)。由于此种新型光镊对光能的利用率极高,能量密度低于传统光镊近3个数量级,并可实现颗粒的大范围操控,极大地拓展了光镊可操控粒子的种类,已经成为纳米技术以及生命科学领域的重要研究工具。温度场光镊仍面临诸多问题,例如对于颗粒界面调控的依赖性以及三维捕获受限等,尤其是在生物光子学的研究中,还需要进一步发展和优化。本文对光致温度场光镊操控基本原理及其在生物医学中的应用两个方面进行了系统阐述,并对其今后的发展与挑战进行了展望。
Significance Optical tweezers have revolutionized the field of biological research with their unique advantages of noncontact and highprecision manipulation of various particles,including biomolecules.In 1986,Arthur Ashkin pioneered the development of optical tweezers by demonstrating their ability to capture microspheres in three dimensions,and his pioneering work had earned him a Nobel Prize in 2018.However,the optothermal effect and diffraction limit of lasers in traditional optical trapping techniques have restricted its wider applications.Nevertheless,in the past decade,researchers have turned the optothermal effect into a merit.With the synergy effect of optics and thermodynamics,one can perform highprecision nanoparticle manipulation in a largescale range,which is called optical temperature fielddriven tweezers(OTFT).This new type of tweezers can operate in rather low light density,which is two to three orders of magnitude lower than that of conventional optical tweezers.In addition,with the assistance of thermal energy,it greatly expands the categories of particles that can be manipulated,allowing for the largescale manipulation of particles that limit the application of optical tweezers,such as opaque particles,metallic nanoparticles,and biomolecules.OTFT has become a useful research tool that enables researchers to study biological particles with high precision.Particularly in the detection of individual bionanoparticles,such as viruses,bacteria,proteins,and DNAs.The ability to detect single bionanoparticles enables observation of biological behavior on an individual level,which allows us to develop effective disease prevention strategies and expand our understanding of the biological world.Progress In this review,we systematically demonstrate the manipulation principles of OTFT and its applications in the biological field.In addition,the future development and challenges of OTFT are also discussed.Firstly,we provide a brief analysis of conventional optical tweezers(Fig.1).Secondly,we demonstrate the basic principles of the common optothermal effects such as thermophoresis,thermoelectricity,electrothermoplasmonic flow,natural convection,thermal osmotic flow,depletion forces,and Marangoni convection(Figs.2-6).Thirdly,we provide an indepth analysis of OTFT′s applications in biomedicine,such as manipulation of nanoparticles(Figs.7-8),protein molecules(Figs.9-10),nucleic acid molecules(Figs.11-13),and sorting of other nanobioparticles(Figs.14-18),as well as the sensitizing effect of biosensing(Fig.19).Notably,the study by Dieter Braun and Albert Libchaber regarding the capture of DNA through convection and thermophoresis in 2002 is often considered a pioneering study in using OTFT for biomolecule capture(Fig.11).Lately,in 2015,Ho Pui Ho′s group in The Chinese University of Hong Kong developed a series of optothermal manipulation schemes to capture nanoparticles or cells(Figs.7,15-17).In 2018,Zheng Yuebing′s group in University of Texas at Austin utilized surfactants in OTFT to achieve precise manipulation and onsite spectroscopic detection of metal nanospheres(Fig.8).In 2019,Cichos′s group at Leipzig University developed a thermophoretic trapping and rotational diffusion measurement scheme for single amyloid fibrils,which may be useful for understanding neurodegenerative disorders(Fig.9).In 2020,Ndukaife′s group at Vanderbilt University combined OTFT with alternating electric fields to capture and manipulate individual protein molecules as small as 3.6 nm in diameter(Fig.10).Furthermore,in 2021,Zheng Yuebing′s group also accomplished the capture of nanoparticles via optorefrigerative effectinduced temperature field,thereby avoiding the possible optothermal damage to the captured particles.In 2022,A method for biomolecule enrichment and interaction enhancement was developed by our team using flipped thermophoretic force(Fig.19).This approach significantly boosted the sensitivity of conventional surface plasmon resonance imaging(SPRI)sensing methods by a factor of 23.6.These typical advances in OTFT technology mark a significant milestone,as they bring about notable enhancements in functionality and broaden the scope of potential applications for OTFT in areas such as nanotechnology and life sciences.Conclusions and Prospects The implementation of OTFT relies heavily on various hydrodynamic effects generated by the temperature field and still faces several challenges.Firstly,the temperature gradient may cause some biologically active targets to lose their activity during manipulation.Secondly,various factors,such as ion concentration,temperature,pH value,and type,can easily affect the direction and size of particles driven by the temperature field.As a result,some optothermal tweezers require the addition of surfactants to modify the manipulated targets and achieve controlled particle capture.However,most surfactants are not compatible with biologically active particles and may lead to chemical toxicity or changes in the spatial structure of protein molecules.Additionally,the adsorption of surfactants may change the surface electrical properties of manipulated targets,thereby affecting their physicochemical properties.Thirdly,while OTFT currently utilizes twodimensional potential wells to capture particles,the construction of spatial threedimensional potential well capture remains a significant challenge.In terms of future research directions for OTFT,efforts will be made on the development of biocompatible surfactants or the modulation of other environmental factors to achieve controlled and targeted particle trapping,especially in the field of biology.Furthermore,OTFT can be effectively integrated with other fields to address a broader range of issues.For instance,the combination of OTFT with dielectric microspherebased superresolution imaging enables large fieldofview imaging via microsphere scanning.OTFT can also be combined with surface Ramanenhanced scattering to enhance its chemical detection performance.In addition,OTFT is expected to be integrated with optical spanners to study the manipulation of the molecular orientation of liquid crystals.It can be anticipated that with the development of research on the light and matter interaction as well as surface chemistry,the opticallyinduced temperature field optical trapping technology will be further improved and will shine in the fields of biomedical and biochemical detection.
作者
钟义立
彭宇航
陈嘉杰
周健行
戴小祺
张晗
屈军乐
邵永红
Zhong Yili;Peng Yuhang;Chen Jiajie;Zhou Jianxing;Dai Xiaoqi;Zhang Han;Qu Junle;Shao Yonghong(College of Physics and Optoelectronic Engineering,Key Laboratory of Radio Frequency Heterogeneous Integration,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,Shenzhen University,Shenzhen 518060,Guangdong,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第14期1-21,共21页
Acta Optica Sinica
基金
国家自然科学基金(62275164,61905145,62275168)
国家重点研发计划(2022YFA1200116)
广东省自然科学基金(2021A1515011916)
广东省重大人才工程引进类项目(2021QN02Y124)
深圳市科技计划项目(ZDSYS20210623092006020)。
关键词
光镊
光热镊
光流控
光热效应
微流控
生物传感器
optical tweezers
optothermal tweezers
optofluidics
optothermal effects
microfluidics
biosensors
