Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution e...Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution enhancement can only increase the spatial resolution of micros-copy by a factor of two at most because the frequency of the structured illumination pattern is limited by the cutoff frequency of the excitation point spread function.The frequency of the pattern generated by the nonlinear response in samples is not limited;therefore,nonlinear SIM(NL-SIM),in theory,has no inherent limit to the resolution.In the present study,we describe a two-photon nonlinear SIM(2P-SIM)technique using a multiple harmonics scanning pattern that employs a composite structured illumination pattern,which can produce a higher order harmonic pattern based on the fluorescence nonlinear response in a 2P process.The theoretical models of super-resolution imaging were established through our simulation,which describes the working mechanism of the multi-frequency structure of the nonsinusoidal function to improve the reso-lution.The simulation results predict that a 5-fold improvement in resolution in the 2P-SIM is possible.展开更多
We describe a multiphoton(mP)-structured illumination microscopy(SIM)technique,which demonstrates substantial improvement in image resolution compared with linear SIM due to the nonlinear response of fluorescence.This...We describe a multiphoton(mP)-structured illumination microscopy(SIM)technique,which demonstrates substantial improvement in image resolution compared with linear SIM due to the nonlinear response of fluorescence.This nonlinear response is caused by the effect of nonsinusoidal structured illumination created by scanning a sinusoidally modulated illumination to excite an mP fluorescence signal.The harmonics of the structured fluorescence illumination are utilised to improve resolution.We present an mP-SIM theory for reconstructing the super-resolution image of the system.Theoretically,the resolution of our m P-SIM is unlimited if all the high-order harmonics of the nonlinear response of fluorescence are considered.Experimentally,we demonstrate an 86 nm lateral resolution for two-photon(2P)-SIM and a 72 nm lateral resolution for second-harmonic-generation(SHG)-SIM.We further demonstrate their application by imaging cells stained with F-actin and collagen fibres in mouse-tail tendon.Our method can be directly used in commercial mP microscopes and requires no specific fluorophores or high-intensity laser.展开更多
Surface plasmonic resonance(SPR)has been a corner stone for approaching single molecular detection due to its highsensitivity capability and simple detection mechanism,and has brought major advancements in biomedicine...Surface plasmonic resonance(SPR)has been a corner stone for approaching single molecular detection due to its highsensitivity capability and simple detection mechanism,and has brought major advancements in biomedicine and life science technology.Over decades,the successful integration of SPR with versatile techniques has been demonstrated.However,several crucial limitations have hindered this technique for practical applications,such as long detection time and low overall sensitivity.This review aims to provide a comprehensive summary of existing approaches in enhancing the performance of SPR sensors based on“passive”and“active”methods.Firstly,passive enhancement is discussed from a material aspect,including signal amplification tags and modifications of conventional substrates.Then,the focus is on the most popular active enhancement methods including electrokinetic,optical,magnetic,and acoustic manipulations that are summarized with highlights on their advantageous features and ability to concentrate target molecules at the detection sites.Lastly,prospects and future development directions for developing SPR sensing towards a more practical,single molecular detection technique in the next generation are discussed.This review hopes to inspire researchers’interests in developing SPR-related technology with more innovative and influential ideas.展开更多
Singlet fission(SF)is a spin-conserving process converting 1 singlet exciton into 2 triplet excitons.This exciton multiplication mechanism offers an attractive route to solar cells that circumvent the single-junction ...Singlet fission(SF)is a spin-conserving process converting 1 singlet exciton into 2 triplet excitons.This exciton multiplication mechanism offers an attractive route to solar cells that circumvent the single-junction Shockley–Queisser limit.However,it remains unclear how intermolecular coupling,which is subject to the aggregation extent in thin-film morphology,controls SF pathways and dynamics.The prototype molecule 6,13-bis(triisopropylsilylethynyl)-pentacene(TIPS-pentacene)has been extensively studied to investigate SF mechanisms.However,previous literature reports have presented divergent SF mechanisms and pathways in TIPS-pentacene films.In this study,solvent vapor annealing treatment is used to deliberately adjust the aggregation extent in TIPS-pentacene films.This enables us to reproduce various SF pathways reported in the literature under the same experimental conditions,with the only variation being the level of aggregation.These results shed light on the crucial role that molecular aggregation plays in modulating both the SF mechanism and pathway and reconciles the previously contentious SF mechanisms and pathways reported in TIPS-pentacene films.Our study offers substantial insights into the understanding of the SF mechanism and provides a potential avenue for future control of SF pathways in accordance with specific application requirements.展开更多
基金This work Was supported by National Natural Science Foundation of China(grant nos.61775148,61527827,and 61905145)Guangdong Natural Science Foundation and Province Project(2021A1515011916)Shenzhen Science and Technology R&D and Innovation Foundation(grant nos.JCYJ20200109105608771.J CYJ20180305124754860 and JCYJ20180228162956597).
文摘Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution enhancement can only increase the spatial resolution of micros-copy by a factor of two at most because the frequency of the structured illumination pattern is limited by the cutoff frequency of the excitation point spread function.The frequency of the pattern generated by the nonlinear response in samples is not limited;therefore,nonlinear SIM(NL-SIM),in theory,has no inherent limit to the resolution.In the present study,we describe a two-photon nonlinear SIM(2P-SIM)technique using a multiple harmonics scanning pattern that employs a composite structured illumination pattern,which can produce a higher order harmonic pattern based on the fluorescence nonlinear response in a 2P process.The theoretical models of super-resolution imaging were established through our simulation,which describes the working mechanism of the multi-frequency structure of the nonsinusoidal function to improve the reso-lution.The simulation results predict that a 5-fold improvement in resolution in the 2P-SIM is possible.
基金supported by the Project from the National Key Research and Development Program of China(2017YFB0403804)the National Natural Science Foundation of China(61775148 and61527827)the Shenzhen Science and Technology R&D and Innovation Foundation(JCYJ20180305124754860 and JCYJ20200109105608771)。
文摘We describe a multiphoton(mP)-structured illumination microscopy(SIM)technique,which demonstrates substantial improvement in image resolution compared with linear SIM due to the nonlinear response of fluorescence.This nonlinear response is caused by the effect of nonsinusoidal structured illumination created by scanning a sinusoidally modulated illumination to excite an mP fluorescence signal.The harmonics of the structured fluorescence illumination are utilised to improve resolution.We present an mP-SIM theory for reconstructing the super-resolution image of the system.Theoretically,the resolution of our m P-SIM is unlimited if all the high-order harmonics of the nonlinear response of fluorescence are considered.Experimentally,we demonstrate an 86 nm lateral resolution for two-photon(2P)-SIM and a 72 nm lateral resolution for second-harmonic-generation(SHG)-SIM.We further demonstrate their application by imaging cells stained with F-actin and collagen fibres in mouse-tail tendon.Our method can be directly used in commercial mP microscopes and requires no specific fluorophores or high-intensity laser.
基金the National Natural Science Foundation of China(No.61905145)Guangdong Natural Science Foundation and Province Project(No.2021A1515011916)Shenzhen Science and Technology R&D and Innovation Foundation(No.JCYJ20200109105608771).
文摘Surface plasmonic resonance(SPR)has been a corner stone for approaching single molecular detection due to its highsensitivity capability and simple detection mechanism,and has brought major advancements in biomedicine and life science technology.Over decades,the successful integration of SPR with versatile techniques has been demonstrated.However,several crucial limitations have hindered this technique for practical applications,such as long detection time and low overall sensitivity.This review aims to provide a comprehensive summary of existing approaches in enhancing the performance of SPR sensors based on“passive”and“active”methods.Firstly,passive enhancement is discussed from a material aspect,including signal amplification tags and modifications of conventional substrates.Then,the focus is on the most popular active enhancement methods including electrokinetic,optical,magnetic,and acoustic manipulations that are summarized with highlights on their advantageous features and ability to concentrate target molecules at the detection sites.Lastly,prospects and future development directions for developing SPR sensing towards a more practical,single molecular detection technique in the next generation are discussed.This review hopes to inspire researchers’interests in developing SPR-related technology with more innovative and influential ideas.
基金supported by the National Natural Science Foundation of China(62375056 and 11874125)the Guangdong Basic and Applied Basic Research Foundation(2022A1515011951).
文摘Singlet fission(SF)is a spin-conserving process converting 1 singlet exciton into 2 triplet excitons.This exciton multiplication mechanism offers an attractive route to solar cells that circumvent the single-junction Shockley–Queisser limit.However,it remains unclear how intermolecular coupling,which is subject to the aggregation extent in thin-film morphology,controls SF pathways and dynamics.The prototype molecule 6,13-bis(triisopropylsilylethynyl)-pentacene(TIPS-pentacene)has been extensively studied to investigate SF mechanisms.However,previous literature reports have presented divergent SF mechanisms and pathways in TIPS-pentacene films.In this study,solvent vapor annealing treatment is used to deliberately adjust the aggregation extent in TIPS-pentacene films.This enables us to reproduce various SF pathways reported in the literature under the same experimental conditions,with the only variation being the level of aggregation.These results shed light on the crucial role that molecular aggregation plays in modulating both the SF mechanism and pathway and reconciles the previously contentious SF mechanisms and pathways reported in TIPS-pentacene films.Our study offers substantial insights into the understanding of the SF mechanism and provides a potential avenue for future control of SF pathways in accordance with specific application requirements.
