Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application p...Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security.展开更多
The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed min...The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed miniemulsion polymerization process,in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix,respectively.The obtained nanocomposites with a high relative fluorescence quantum yield（Q）exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer.The stability of photomerocyanine was also improved.展开更多
An interest in the fluorescent protein asFP595 is due to unexplained puzzles in its photophysical behavior. We report the results of calculations of structures, absorption, and emission bands in asFP595 by considering...An interest in the fluorescent protein asFP595 is due to unexplained puzzles in its photophysical behavior. We report the results of calculations of structures, absorption, and emission bands in asFP595 by considering model molecular clusters in the coordinate-locking scheme. Both trans and cis conformations of the anionic chromophore are considered. Equilibrium geometry coordinates on the ground potential energy surface were optimized in the density functional theory approaches by considering both large- and reduced-size clusters. The cluster size was reduced to locate positions of the minimum energy points on the excited-state potential surface by using the configuration interaction singles approach. Vertical excitation energies and oscillator strengths were computed by using the ZINDO method. We show that consideration of large clusters mimicking the protein-containing pocket is an essential issue to calculate positions of absorption and emission bands with the accuracy compatible to experiments.展开更多
Photo-responsive azobenzene （ABZ） derivatives with different end groups （R） as photoswitchable molecules were employed to construct self-assembled monolayers （SAMs） on silicon substrate by using 3-glycidoxypropy...Photo-responsive azobenzene （ABZ） derivatives with different end groups （R） as photoswitchable molecules were employed to construct self-assembled monolayers （SAMs） on silicon substrate by using 3-glycidoxypropyltrimethoxysilane （GPTS） as the bridging molecules. The assembly process was optimized by changing various parameters, including the type and concentration of ABZ derivatives, reaction time, etc. The obtained SAMs were fully characterized and evaluated using UV spectroscopy, atomic force microscope （AFM）, elllipsometer, static contact angle and X-ray photoelectron spectroscopy （XPS）. It is found that the end group property of azobenzene derivatives is critical to the obtained SAMs＇ photoresponsive properties. Compared with hydrophobic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-CF3）, the hydrophilic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-COOH） show excellent reversible photoswitching performance with a large contact angle change of 35° under oDtimized process, and the SAMs are removable bv thermal treatment at 240 ℃ in air for onlv 5 min.展开更多
Fluorescent reporter proteins that allow repeated switching between a fluorescent and a non-fluorescent state in response to specific wavelengths of light are novel tools for monitoring of protein trafficking and supe...Fluorescent reporter proteins that allow repeated switching between a fluorescent and a non-fluorescent state in response to specific wavelengths of light are novel tools for monitoring of protein trafficking and super-resolu- tion fluorescence microscopy in living organisms. Here, we describe variants of the reversibly photoswitchable fluores- cent proteins rsFastLime, bsDronpa, and Padron that have been codon-optimized for the use in transgenic Arabidopsis plants. The synthetic proteins, designated rsFastLIME-s, bsDRONPA-s, and PADRON C-s, showed photophysical properties and switching behavior comparable to those reported for the original proteins. By combining the ＇positively switchable＇ PADRON C-s with the ＇negatively switchable＇ rsFastLIME-s or bsDRONPA-s, two different fluorescent reporter proteins could be imaged at the same wavelength upon transient expression in Nicotiana benthamiana cells. Thus, co-localiza- tion analysis can be performed using only a single detection channel. Furthermore, the proteins were used to tag the RNA-binding protein AtGRP7 （Arabidopsis thaliana glycine-rich RNA-binding protein 7） in transgenic Arabidopsis plants. Because the new reversibly photoswitchable fluorescent proteins show an increase in signal strength during each pho- toactivation cycle, we were able to generate a large number of scans of the same region and reconstruct 3-D images of AtGRP7 expression in the root tip. Upon photoactivation of the AtGRP7：rsFastLIME-s fusion protein in a defined region of a transgenic Arabidopsis root, spreading of the fluorescence signal into adjacent regions was observed, indicating that movement from cell to cell can be monitored. Our results demonstrate that rsFastLIME-s, bsDRONPA-s, and PADRON C-s are versatile fluorescent markers in plants, Furthermore, the proteins also show strong fluorescence in mammalian cells including COS-7 and HeLa cells.展开更多
Here,we introduce the first experimental proof of coherent oscillation and coupling of photoswitchable molecules embedded randomly in a polymeric matrix and acting cooperatively upon illumination with UV light.In part...Here,we introduce the first experimental proof of coherent oscillation and coupling of photoswitchable molecules embedded randomly in a polymeric matrix and acting cooperatively upon illumination with UV light.In particular,we demonstrate the specular reflection and Brewster phenomenon alteration of photochromic molecular dipole antennas.We successfully demonstrate the concept of Brewster wavelength,which is based on the dipolar interaction between radiating dipoles and the surrounding matrix possessing a net dipole moment,as a key tool for highly localized sensing of matrix polarity.We also introduce the concept of‘tailored molecular photonic coupling’while highlighting the role of interferences for the design of optically active media by adjusting the photonic response of the medium with the real and imaginary refractive index of photoswitchable molecules in the‘ON’state.Our results enhance our fundamental understanding of coherent dipole radiation and open a new vein of research based on glassy disordered dipolar composites that act as macroscopic antenna with cooperative action;furthermore,these results have important implications for new design rules of tailored photonics.展开更多
Stimulated Raman scattering(SRS)microscopy has shown superior chemical resolution due to the much narrower vibrational spectral bandwidth than its fluorescence counterpart.However,breaking the diffraction-limited spat...Stimulated Raman scattering(SRS)microscopy has shown superior chemical resolution due to the much narrower vibrational spectral bandwidth than its fluorescence counterpart.However,breaking the diffraction-limited spatial resolution of SRS imaging is much more challenging because of the intrinsically weak scattering cross section and inert/stable nature of molecular bond vibrations.We report superresolution SRS(SR-SRS)nanoscopy based on reversible-switchable vibrational photochromic probes integrated with point spread function engineering strategy.By introducing a Gaussian-shaped ultraviolet excitation beam and a donut-shaped visible depletion beam in addition to the pump and Stokes beams,SR-SRS could reach sub-100 nm resolution on photoswitchable nanoparticles(NPs).Furthermore,NP-treated live cell imaging was demonstrated with resolution improvement by a factor of∼4.Our proof-of-principle work provides the potential for SR vibrational imaging to assist research on complex biological systems.展开更多
Precise modulation of neuronal activity by neuroactive molecules is essential for understanding brain circuits and behavior.However,tools for highly controllable molecular release are lacking.Here,we developed a photo...Precise modulation of neuronal activity by neuroactive molecules is essential for understanding brain circuits and behavior.However,tools for highly controllable molecular release are lacking.Here,we developed a photoswitchable nanovesicle with azobenzene-containing phosphatidylcholine(azo-PC),coined‘azosome’,for neuromodulation.Irradiation with 365 nm light triggers the trans-to-cis isomerization of azo-PC,resulting in a disordered lipid bilayer with decreased thickness and cargo release.Irradiation with 455 nm light induces reverse isomerization and switches the release off.Real-time fluorescence imaging shows controllable and repeatable cargo release within seconds(<3 s).Importantly,we demonstrate that SKF-81297,a dopamine D1-receptor agonist,can be repeatedly released from the azosome to activate cultures of primary striatal neurons.Azosome shows promise for precise optical control over the molecular release and can be a valuable tool for molecular neuroscience studies.展开更多
Light-induced recognition,assemblies,and materials are intensive areas of research due to their high spatiotemporal resolution.Herein,we demonstrated photoswitchable molecular recognition via dithienylethene-triggered...Light-induced recognition,assemblies,and materials are intensive areas of research due to their high spatiotemporal resolution.Herein,we demonstrated photoswitchable molecular recognition via dithienylethene-triggeredreversible structural regulation of dynamic covalent hydrazone bonds.By combining dithienylethenes and cyclic hemiacetals,the photochemical open-ring and closed-ring forms enabled turningoff and on the creation of awide range of hydrazones when desired.Light-induced bidirectional switching between hydrazones and their cyclization structures promoted by a neighboring carboxyl group was further achieved.By taking advantage of reversible structural changes totoggleon andoff the binding pocket,photoswitchable recognitionofmetal ionswas realized.Finally,the construction of an acylhydrazone polymer offered a facile way for light-mediated selective extraction/release.The strategies and results reported here should find applications in many contexts,such asdynamicassemblies,molecular switches,and smart materials.展开更多
For the main purpose of manipulating the functions of molecules, researchers have made great achievements on photoresponsive molecules using light as a trigger. Light has become a promising scientific tool due to it b...For the main purpose of manipulating the functions of molecules, researchers have made great achievements on photoresponsive molecules using light as a trigger. Light has become a promising scientific tool due to it being a clean and noninvasive external stimulant. By attachment of photoresponsive moieties to molecules, the biological activities of molecules can be attenuated by light activation. With wide applications of laser in life sciences, it will be possible to achieve high spatiotemporal resolution. In this review, we focus on photoresponsive nucleic acids for photomodulating gene expression with light activation. With incorporation of photoswitchable or photocleavable moieties, biological behaviors of nucleic acids are photoregulated reversibly or irreversibly. Recent development and applications of photoresponsive nucleic acid in vitro and in vivo have shown a very promising future for manipulation of specific functional genes or disease genes. We expect that photoresponsive nucleic acids will be powerful scientific tools for studying biological events as well as gene therapy agents for genetic diseases.展开更多
The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties w...The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy（POM）,differential scanning calorimetry（DSC） and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.展开更多
The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 a...The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 and H-Phe-Tyr-Ψ[CS-N]- Pro-Trp-Gly-NH_2 were studied by UV-vis absorption.The isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]- D-Ala-NH_2 and Ac-Tyr-Ψ[CS-N]-Pro-NH_2 picked from the two peptides,were calculated using ab initio method.The cis isomer of CS-N is more stable than th...展开更多
Tetraphenylethene(TPE),a star building block with promising aggregationinduced emission,has received much interest.Given that its intramolecular Woodward-Hoffmann cyclic intermediate instantaneously converts back to t...Tetraphenylethene(TPE),a star building block with promising aggregationinduced emission,has received much interest.Given that its intramolecular Woodward-Hoffmann cyclic intermediate instantaneously converts back to the original state within several picoseconds,the essentially photochromic characteristic of TPE is little investigated.Achieving a visible photocyclization of TPE is still an unsolved issue and considered as the bottleneck in the further advancement of applications.We report a strategy of attaching carbonate ester onto the TPE skeleton(TPE-4C)to enhance TPE photocyclization stability.As demonstrated,the incorporated cholesteryloxycarbonyloxy substituents in TPE-4C can increase the energy barrier for cycloreversion,thereby exhibiting extremely thermal stability of photocyclic intermediate upon UV irradiation,prolonging its lifetime from 63 picoseconds to 46 s by 7.2×10^(11)-fold.The photoinduced cyclization of TPE-4C could be monitored with naked eyes,and the photocyclization/cycloreversion is achieved by turning on/off UV light along with a relative fatigue resistance.Encapsulation of TPE-4C into the liquid crystal can induce a striking phase transformation(achiral↔chiral),which can be applicable to encode optical information.Employing carbonate ester into the TPE unit plays a vital role in enhancing the unprecedented TPE photocyclization stability,providing a toolbox to allow TPE-based photocyclization to be visually monitored.展开更多
Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting ...Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only vip)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable vip further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.展开更多
Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism a...Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb concentrations.Reversible multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal stimuli.After 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb sample.Besides,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 K.These results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.展开更多
1.Introduction The introduction of photoswitches into the bioactive substances is the fundamental idea behind photopharmacology.Upon light irradiation,the drug activity can be spatiotemporally controlled by the photon...1.Introduction The introduction of photoswitches into the bioactive substances is the fundamental idea behind photopharmacology.Upon light irradiation,the drug activity can be spatiotemporally controlled by the photon-induced variety of photoswitch's structures or characteristics[1].However,some challenges are still faced in photopharmacology including phototoxicity and limited tissue penetration depth(about a few millimeters).展开更多
Recent advancements in single-molecule biophysics have been driven by breakthroughs in advanced fluorescence microscopy techniques and the development of nextgeneration organic fluorophores.These cutting-edge fluoroph...Recent advancements in single-molecule biophysics have been driven by breakthroughs in advanced fluorescence microscopy techniques and the development of nextgeneration organic fluorophores.These cutting-edge fluorophores,coupled through tailored biolabeling strategies,offer single-molecule brightness,photostability,and phototunability(i.e.,photoswitchable,photoactivatable),contributing to enhancing spatial and temporal imaging resolution for studying biomolecular interactions and dynamics at single-event precision.This review examines the progress made over the past decade in the development of next-generation fluorophores,along with their site-specific labeling methods for proteins,nucleic acids,and biomolecular complexes.It also explores their applications in single-molecule fluorescencebased dynamic structural biology and super-resolution microscopy imaging.Furthermore,it examines ongoing efforts to address challenges associated with fluorophore photostability,photobleaching,and the integration of advanced photophysical and photochemical functionalities.The integration of state-of-the-art fluorophores with advanced labeling strategies aim to deliver complementary correlative data,holding promise for revolutionizing single-molecule biophysics by pushing the boundaries of temporal and spatial imaging resolution to unprecedented limits.展开更多
The visible light-driven photoswitches are attracting widespread attention,but it is challenging to leverage their phototriggered structural changes to regulate dynamic bonds,assemblies,and materials.Herein,we incorpo...The visible light-driven photoswitches are attracting widespread attention,but it is challenging to leverage their phototriggered structural changes to regulate dynamic bonds,assemblies,and materials.Herein,we incorporated reversible covalent sites of aldehyde ring-chain tautomers into all-visible-light azobenzenes toward a versatile platform for light-controlled formation/exchange of dynamic C—N bonds from secondary amines.The movement of ring-chain equilibrium was attained via manipulating intramolecular multiple hydrogen bonding from E/Z configurational isomers.Such structural regulation further enabled photocontrolled kinetics for the formation and exchange reactions of cyclic hemiaminal ethers from secondary amines exhibiting kinetic rate reversal from E/Z isomers.The varied capability of E/Z configurational isomers in engaging in multiple hydrogen bonds of azo attached carboxylate with ammonium salt accounts for the difference.Moreover,the photoswitching performance of azobenzenes in different solutions was readily regulated by dynamic covalent reactions with amines.The dynamic reactivity control with visible light and associated mechanistic foundation add into the collection of photoswitchable dynamic covalent chemistry and would lay the foundation for subsequent biological and material applications.展开更多
Molecular photoswitches hold an important position in chemical research,and it is of significance to develop novel structures and mechanisms.Herein we report a new type of E/Z photoswitches in tellurazole/tellurazoliu...Molecular photoswitches hold an important position in chemical research,and it is of significance to develop novel structures and mechanisms.Herein we report a new type of E/Z photoswitches in tellurazole/tellurazolium-based olefin scaffolds,wherein intramolecular through-space n→π^(*)orbital interaction plays a stabilizing role in the Z isomer approaching quantitative conversion.The manipulation of diverse noncovalent interactions,including intermolecular chalcogen bonding,further provided versatile handles for regulating molecular recognition and multiaddressable switching.Despite bidirectional E/Z photoisomerization with neutral tellurazole derivatives,protonation-induced cationic tellurazoliums allowed significant enhancement in the efficiency of Z→E switching(E up to 73%)while maintaining high percentage E→Z switching(Z up to 95%),as chalcogen bonding with counteranions contributes to the stabilization of electron-accepting tellurazoliums affording a larger wavelength difference between E/Z isomers.Furthermore,the n→π^(*)orbital interaction enables the preference of Z isomer in the ground state for N-methyl tellurazoliums.Bidirectional E/Z photoswitching with high conversion(Z up to 99%,E up to 81%)was attained,and E→Z isomerization can also be invoked by nucleophilic catalysis,making N-methyl tellurazoliums as T-type photoswitches.The results showcase the power of noncovalent interactions for controlling molecular photoswitches and should set the scene for vip recognition,dynamic assemblies,and responsive materials.展开更多
The wide application of photoswitches requires control over their isomerization dynamics.Utilizing noncovalent interactions is a promising strategy as it offers active regulation in-situ.However,this control strategy ...The wide application of photoswitches requires control over their isomerization dynamics.Utilizing noncovalent interactions is a promising strategy as it offers active regulation in-situ.However,this control strategy has not yet been explored in-depth to reach its full potential.In this work,we demonstrate that by directing noncovalent interactions to the central rotating bond of indigo-based photoswitches,their thermal relaxation dynamics were altered in two opposite directions(either slowed down or sped up)allowing for modulating the relaxation half-lives across four orders of magnitude.More importantly,our work established two distinct and orthogonal working mechanisms of noncovalent control over isomerization:(1)Thermodynamic stabilization of photoisomers;and(2)Facilitating an alternative reaction pathway through Brønsted/Lewis acid catalysis.This two-directional modulation(resembling agonists and inverse agonists in biological systems)via two orthogonal working mechanisms will enable more delicate manipulation of photoswitches for advanced applications.展开更多
基金financially supported by the National Key R&D Program of China(Nos.2023YFB3812400,2023YFB3812403)National Natural Foundation of China(Nos.52273206,52350233)+1 种基金Hunan Provincial Natural Science Foundation(No.2021JJ10029)Huxiang High-level Talent Gathering Project(No.2022RC4039).
文摘Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security.
文摘The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed miniemulsion polymerization process,in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix,respectively.The obtained nanocomposites with a high relative fluorescence quantum yield（Q）exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer.The stability of photomerocyanine was also improved.
文摘An interest in the fluorescent protein asFP595 is due to unexplained puzzles in its photophysical behavior. We report the results of calculations of structures, absorption, and emission bands in asFP595 by considering model molecular clusters in the coordinate-locking scheme. Both trans and cis conformations of the anionic chromophore are considered. Equilibrium geometry coordinates on the ground potential energy surface were optimized in the density functional theory approaches by considering both large- and reduced-size clusters. The cluster size was reduced to locate positions of the minimum energy points on the excited-state potential surface by using the configuration interaction singles approach. Vertical excitation energies and oscillator strengths were computed by using the ZINDO method. We show that consideration of large clusters mimicking the protein-containing pocket is an essential issue to calculate positions of absorption and emission bands with the accuracy compatible to experiments.
基金financially supported by The Dow Chemical Company
文摘Photo-responsive azobenzene （ABZ） derivatives with different end groups （R） as photoswitchable molecules were employed to construct self-assembled monolayers （SAMs） on silicon substrate by using 3-glycidoxypropyltrimethoxysilane （GPTS） as the bridging molecules. The assembly process was optimized by changing various parameters, including the type and concentration of ABZ derivatives, reaction time, etc. The obtained SAMs were fully characterized and evaluated using UV spectroscopy, atomic force microscope （AFM）, elllipsometer, static contact angle and X-ray photoelectron spectroscopy （XPS）. It is found that the end group property of azobenzene derivatives is critical to the obtained SAMs＇ photoresponsive properties. Compared with hydrophobic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-CF3）, the hydrophilic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-COOH） show excellent reversible photoswitching performance with a large contact angle change of 35° under oDtimized process, and the SAMs are removable bv thermal treatment at 240 ℃ in air for onlv 5 min.
文摘Fluorescent reporter proteins that allow repeated switching between a fluorescent and a non-fluorescent state in response to specific wavelengths of light are novel tools for monitoring of protein trafficking and super-resolu- tion fluorescence microscopy in living organisms. Here, we describe variants of the reversibly photoswitchable fluores- cent proteins rsFastLime, bsDronpa, and Padron that have been codon-optimized for the use in transgenic Arabidopsis plants. The synthetic proteins, designated rsFastLIME-s, bsDRONPA-s, and PADRON C-s, showed photophysical properties and switching behavior comparable to those reported for the original proteins. By combining the ＇positively switchable＇ PADRON C-s with the ＇negatively switchable＇ rsFastLIME-s or bsDRONPA-s, two different fluorescent reporter proteins could be imaged at the same wavelength upon transient expression in Nicotiana benthamiana cells. Thus, co-localiza- tion analysis can be performed using only a single detection channel. Furthermore, the proteins were used to tag the RNA-binding protein AtGRP7 （Arabidopsis thaliana glycine-rich RNA-binding protein 7） in transgenic Arabidopsis plants. Because the new reversibly photoswitchable fluorescent proteins show an increase in signal strength during each pho- toactivation cycle, we were able to generate a large number of scans of the same region and reconstruct 3-D images of AtGRP7 expression in the root tip. Upon photoactivation of the AtGRP7：rsFastLIME-s fusion protein in a defined region of a transgenic Arabidopsis root, spreading of the fluorescence signal into adjacent regions was observed, indicating that movement from cell to cell can be monitored. Our results demonstrate that rsFastLIME-s, bsDRONPA-s, and PADRON C-s are versatile fluorescent markers in plants, Furthermore, the proteins also show strong fluorescence in mammalian cells including COS-7 and HeLa cells.
基金We gratefully acknowledge financial support from the German Research Foundation(DFG)through SFB677(C09)and partial financial support from SFB677(C01)as well as the German Academic Exchange Service(DAAD)ME thanks the Initiative and Networking Fund of the Helmholtz Association(Grant no.VH-NG-523)for providing the financial support to start his research group.
文摘Here,we introduce the first experimental proof of coherent oscillation and coupling of photoswitchable molecules embedded randomly in a polymeric matrix and acting cooperatively upon illumination with UV light.In particular,we demonstrate the specular reflection and Brewster phenomenon alteration of photochromic molecular dipole antennas.We successfully demonstrate the concept of Brewster wavelength,which is based on the dipolar interaction between radiating dipoles and the surrounding matrix possessing a net dipole moment,as a key tool for highly localized sensing of matrix polarity.We also introduce the concept of‘tailored molecular photonic coupling’while highlighting the role of interferences for the design of optically active media by adjusting the photonic response of the medium with the real and imaginary refractive index of photoswitchable molecules in the‘ON’state.Our results enhance our fundamental understanding of coherent dipole radiation and open a new vein of research based on glassy disordered dipolar composites that act as macroscopic antenna with cooperative action;furthermore,these results have important implications for new design rules of tailored photonics.
基金the financial support from the National Key Research and Development Program of China(Grant No.2021YFF0502900)the National Natural Science Foundation of China(Grant Nos.61975033 and 81771930)+2 种基金the Shanghai Municipal Science and Technology Major Project(Grant Nos.2017SHZDZX01 and 2018SHZDZX01)the financial support from the Shenzhen Science and Technology Innovation Commission(Grant No.KQTD20170810111314625)the National Key Research and Development Program of China(Grant No.2018YFB0407200).
文摘Stimulated Raman scattering(SRS)microscopy has shown superior chemical resolution due to the much narrower vibrational spectral bandwidth than its fluorescence counterpart.However,breaking the diffraction-limited spatial resolution of SRS imaging is much more challenging because of the intrinsically weak scattering cross section and inert/stable nature of molecular bond vibrations.We report superresolution SRS(SR-SRS)nanoscopy based on reversible-switchable vibrational photochromic probes integrated with point spread function engineering strategy.By introducing a Gaussian-shaped ultraviolet excitation beam and a donut-shaped visible depletion beam in addition to the pump and Stokes beams,SR-SRS could reach sub-100 nm resolution on photoswitchable nanoparticles(NPs).Furthermore,NP-treated live cell imaging was demonstrated with resolution improvement by a factor of∼4.Our proof-of-principle work provides the potential for SR vibrational imaging to assist research on complex biological systems.
基金This work was partially supported by National Science Foundation under award number 2123971(Z.Q.,P.A.S.,and S.O.N.)National Institute of Neurological Disorders and Stroke of the National Institutes of Health under award number RF1NS110499(Z.Q.and P.A.S.)a postdoc research grant from the Phospholipid Research Center(Heidelberg,Germany)to H.X.
文摘Precise modulation of neuronal activity by neuroactive molecules is essential for understanding brain circuits and behavior.However,tools for highly controllable molecular release are lacking.Here,we developed a photoswitchable nanovesicle with azobenzene-containing phosphatidylcholine(azo-PC),coined‘azosome’,for neuromodulation.Irradiation with 365 nm light triggers the trans-to-cis isomerization of azo-PC,resulting in a disordered lipid bilayer with decreased thickness and cargo release.Irradiation with 455 nm light induces reverse isomerization and switches the release off.Real-time fluorescence imaging shows controllable and repeatable cargo release within seconds(<3 s).Importantly,we demonstrate that SKF-81297,a dopamine D1-receptor agonist,can be repeatedly released from the azosome to activate cultures of primary striatal neurons.Azosome shows promise for precise optical control over the molecular release and can be a valuable tool for molecular neuroscience studies.
基金supported by National Natural Science Foundation of China(grant nos.22071247,92156010,22101283,and 22101284)the Strategic Priority Research Program(grant no.XDB20000000)+1 种基金the Key Research Program of Frontier Sciences(grant no.QYZDBSSW-SLH030)of the Chinese Academy of Sciences,Natural Science Foundation of Fujian Province(grant nos.2020J06035 and 2022J05085)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(grant no.2021ZR112).
文摘Light-induced recognition,assemblies,and materials are intensive areas of research due to their high spatiotemporal resolution.Herein,we demonstrated photoswitchable molecular recognition via dithienylethene-triggeredreversible structural regulation of dynamic covalent hydrazone bonds.By combining dithienylethenes and cyclic hemiacetals,the photochemical open-ring and closed-ring forms enabled turningoff and on the creation of awide range of hydrazones when desired.Light-induced bidirectional switching between hydrazones and their cyclization structures promoted by a neighboring carboxyl group was further achieved.By taking advantage of reversible structural changes totoggleon andoff the binding pocket,photoswitchable recognitionofmetal ionswas realized.Finally,the construction of an acylhydrazone polymer offered a facile way for light-mediated selective extraction/release.The strategies and results reported here should find applications in many contexts,such asdynamicassemblies,molecular switches,and smart materials.
基金State Key Laboratory of Natural and Biomimetic Drugs and Peking University(bmu2009137-121)
文摘For the main purpose of manipulating the functions of molecules, researchers have made great achievements on photoresponsive molecules using light as a trigger. Light has become a promising scientific tool due to it being a clean and noninvasive external stimulant. By attachment of photoresponsive moieties to molecules, the biological activities of molecules can be attenuated by light activation. With wide applications of laser in life sciences, it will be possible to achieve high spatiotemporal resolution. In this review, we focus on photoresponsive nucleic acids for photomodulating gene expression with light activation. With incorporation of photoswitchable or photocleavable moieties, biological behaviors of nucleic acids are photoregulated reversibly or irreversibly. Recent development and applications of photoresponsive nucleic acid in vitro and in vivo have shown a very promising future for manipulation of specific functional genes or disease genes. We expect that photoresponsive nucleic acids will be powerful scientific tools for studying biological events as well as gene therapy agents for genetic diseases.
基金supported by UMP Research(No.RDU 100338)RAGS(No.RDU131408)
文摘The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy（POM）,differential scanning calorimetry（DSC） and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.
基金supported by the grant from National Natural Science Foundation of China(No.30870526)
文摘The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 and H-Phe-Tyr-Ψ[CS-N]- Pro-Trp-Gly-NH_2 were studied by UV-vis absorption.The isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]- D-Ala-NH_2 and Ac-Tyr-Ψ[CS-N]-Pro-NH_2 picked from the two peptides,were calculated using ab initio method.The cis isomer of CS-N is more stable than th...
基金supported by NSFC/China(21788102,21636002,21622602,21875143,21908146,and 21908060)Shanghai Municipal Science and Technology Major Project(2018SHZDZX03)+3 种基金Innovation Program of Shanghai Municipal Education Commission,Scientific Committee of Shanghai(15XD1501400)Programme of Introducing Talents of Discipline to Universities(B16017)China Postdoctoral Science Foundation(2019M651417)Innovation Research Foundation of Shenzhen(JCYJ20180507182229597).
文摘Tetraphenylethene(TPE),a star building block with promising aggregationinduced emission,has received much interest.Given that its intramolecular Woodward-Hoffmann cyclic intermediate instantaneously converts back to the original state within several picoseconds,the essentially photochromic characteristic of TPE is little investigated.Achieving a visible photocyclization of TPE is still an unsolved issue and considered as the bottleneck in the further advancement of applications.We report a strategy of attaching carbonate ester onto the TPE skeleton(TPE-4C)to enhance TPE photocyclization stability.As demonstrated,the incorporated cholesteryloxycarbonyloxy substituents in TPE-4C can increase the energy barrier for cycloreversion,thereby exhibiting extremely thermal stability of photocyclic intermediate upon UV irradiation,prolonging its lifetime from 63 picoseconds to 46 s by 7.2×10^(11)-fold.The photoinduced cyclization of TPE-4C could be monitored with naked eyes,and the photocyclization/cycloreversion is achieved by turning on/off UV light along with a relative fatigue resistance.Encapsulation of TPE-4C into the liquid crystal can induce a striking phase transformation(achiral↔chiral),which can be applicable to encode optical information.Employing carbonate ester into the TPE unit plays a vital role in enhancing the unprecedented TPE photocyclization stability,providing a toolbox to allow TPE-based photocyclization to be visually monitored.
基金We thank Top-Notch Talents Program of Henan Agricultural University(No.30501049)Project supported by the Science and Technology Department of Henan Province(No.212102310332)the Merit Funding for the Oversea Staff of Henan Province for financial support.
文摘Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only vip)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable vip further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.
基金Project supported by the National Natural Science Foundation of China(52062042,51802164)the Natural Science Foundation of Inner Mongolia(2020MS05044)。
文摘Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb concentrations.Reversible multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal stimuli.After 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb sample.Besides,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 K.These results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.
文摘1.Introduction The introduction of photoswitches into the bioactive substances is the fundamental idea behind photopharmacology.Upon light irradiation,the drug activity can be spatiotemporally controlled by the photon-induced variety of photoswitch's structures or characteristics[1].However,some challenges are still faced in photopharmacology including phototoxicity and limited tissue penetration depth(about a few millimeters).
基金financial support from the National Natural Science Foundation of China(No.22374075)the Start-up Research Fund of Southeast University(4031002412).
文摘Recent advancements in single-molecule biophysics have been driven by breakthroughs in advanced fluorescence microscopy techniques and the development of nextgeneration organic fluorophores.These cutting-edge fluorophores,coupled through tailored biolabeling strategies,offer single-molecule brightness,photostability,and phototunability(i.e.,photoswitchable,photoactivatable),contributing to enhancing spatial and temporal imaging resolution for studying biomolecular interactions and dynamics at single-event precision.This review examines the progress made over the past decade in the development of next-generation fluorophores,along with their site-specific labeling methods for proteins,nucleic acids,and biomolecular complexes.It also explores their applications in single-molecule fluorescencebased dynamic structural biology and super-resolution microscopy imaging.Furthermore,it examines ongoing efforts to address challenges associated with fluorophore photostability,photobleaching,and the integration of advanced photophysical and photochemical functionalities.The integration of state-of-the-art fluorophores with advanced labeling strategies aim to deliver complementary correlative data,holding promise for revolutionizing single-molecule biophysics by pushing the boundaries of temporal and spatial imaging resolution to unprecedented limits.
基金NSFC(S(92156010,22071247,22471274,and 22401279)the Key Research Program of Frontier Sciences(QYZDB-SSW-SLHO3O)of CAS+1 种基金the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20241725)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR112)for funding.
文摘The visible light-driven photoswitches are attracting widespread attention,but it is challenging to leverage their phototriggered structural changes to regulate dynamic bonds,assemblies,and materials.Herein,we incorporated reversible covalent sites of aldehyde ring-chain tautomers into all-visible-light azobenzenes toward a versatile platform for light-controlled formation/exchange of dynamic C—N bonds from secondary amines.The movement of ring-chain equilibrium was attained via manipulating intramolecular multiple hydrogen bonding from E/Z configurational isomers.Such structural regulation further enabled photocontrolled kinetics for the formation and exchange reactions of cyclic hemiaminal ethers from secondary amines exhibiting kinetic rate reversal from E/Z isomers.The varied capability of E/Z configurational isomers in engaging in multiple hydrogen bonds of azo attached carboxylate with ammonium salt accounts for the difference.Moreover,the photoswitching performance of azobenzenes in different solutions was readily regulated by dynamic covalent reactions with amines.The dynamic reactivity control with visible light and associated mechanistic foundation add into the collection of photoswitchable dynamic covalent chemistry and would lay the foundation for subsequent biological and material applications.
基金financially supported by the National Natural Science Foundation of China(grant nos.92156010,22071247,22101283,and 22101284)the Strategic Priority Research Program(grant no.XDB20000000)+1 种基金the Key Research Program of Frontier Sciences(grant no.QYZDB-SSW-SLH030)of Chinese Academy of Sciences,Natural Science Foundation of Fujian Province(grant nos.2020J06035 and 2022J05085)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(grant no.2021ZR112)for support.
文摘Molecular photoswitches hold an important position in chemical research,and it is of significance to develop novel structures and mechanisms.Herein we report a new type of E/Z photoswitches in tellurazole/tellurazolium-based olefin scaffolds,wherein intramolecular through-space n→π^(*)orbital interaction plays a stabilizing role in the Z isomer approaching quantitative conversion.The manipulation of diverse noncovalent interactions,including intermolecular chalcogen bonding,further provided versatile handles for regulating molecular recognition and multiaddressable switching.Despite bidirectional E/Z photoisomerization with neutral tellurazole derivatives,protonation-induced cationic tellurazoliums allowed significant enhancement in the efficiency of Z→E switching(E up to 73%)while maintaining high percentage E→Z switching(Z up to 95%),as chalcogen bonding with counteranions contributes to the stabilization of electron-accepting tellurazoliums affording a larger wavelength difference between E/Z isomers.Furthermore,the n→π^(*)orbital interaction enables the preference of Z isomer in the ground state for N-methyl tellurazoliums.Bidirectional E/Z photoswitching with high conversion(Z up to 99%,E up to 81%)was attained,and E→Z isomerization can also be invoked by nucleophilic catalysis,making N-methyl tellurazoliums as T-type photoswitches.The results showcase the power of noncovalent interactions for controlling molecular photoswitches and should set the scene for vip recognition,dynamic assemblies,and responsive materials.
文摘The wide application of photoswitches requires control over their isomerization dynamics.Utilizing noncovalent interactions is a promising strategy as it offers active regulation in-situ.However,this control strategy has not yet been explored in-depth to reach its full potential.In this work,we demonstrate that by directing noncovalent interactions to the central rotating bond of indigo-based photoswitches,their thermal relaxation dynamics were altered in two opposite directions(either slowed down or sped up)allowing for modulating the relaxation half-lives across four orders of magnitude.More importantly,our work established two distinct and orthogonal working mechanisms of noncovalent control over isomerization:(1)Thermodynamic stabilization of photoisomers;and(2)Facilitating an alternative reaction pathway through Brønsted/Lewis acid catalysis.This two-directional modulation(resembling agonists and inverse agonists in biological systems)via two orthogonal working mechanisms will enable more delicate manipulation of photoswitches for advanced applications.
