The enhancement of the intensity of red upconversion(UC)emission has significant implications for biological applications.In KZnF_(3):Yb^(3+),Er^(3+)which inherently produces high-purity red emission,the introduction ...The enhancement of the intensity of red upconversion(UC)emission has significant implications for biological applications.In KZnF_(3):Yb^(3+),Er^(3+)which inherently produces high-purity red emission,the introduction of Fe^(3+)markedly improves the UC intensity by a factor of 13.The mechanism behind the enhanced UC red luminescence is deduced to originate from the Yb^(3+)-Fe^(3+)dimer,as determined by first principle calculation and analysis of UC luminescence properties.The thermometry performance,based on splitting peaks of red emission,demonstrated enhanced temperature sensitivity at lower ranges.Exploring the photothermal properties,it was observed that temperature exhibited a linear correlation with pump power under a 980 nm laser,achieving levels up to 48℃.This temperature range is ideal for applications in mild photothermal therapy(MPTT).This work elucidates the material’s potential in advanced biological applications,merging optical thermometry and photothermics,indicating its multifunctional utility.展开更多
4-Nonylphenol(NP)is a kind of estrogen belonging to the endocrine disrupter,widely used in various agricultural and industrial goods.However,extensive use of NP with direct release to environment poses high risks to b...4-Nonylphenol(NP)is a kind of estrogen belonging to the endocrine disrupter,widely used in various agricultural and industrial goods.However,extensive use of NP with direct release to environment poses high risks to both human health and ecosystems.Herein,for the first time,we developed near-infrared(NIR)responsive upconversion luminescence nanosensor for NP detection.The Förster resonance energy transfer based upconversion nanoparticles(UCNPs)-graphene oxide sensor offers highly selective and sensitive detection of NP in linear ranges of 5−200 ng/mL and 200−1000 ng/mL under 980 nm and 808 nm excitation,respectively,with LOD at 4.2 ng/mL.The sensors were successfully tested for NP detection in real liquid milk samples with excellent recovery results.The rare-earth fluoride based upconversion luminescence nanosensor with NIR excitation wavelength,holds promise for sensing food,environmental,and biological samples due to their high sensitivity,specific recognition,low LOD,negligible autofluorescence,along with the deep penetration of NIR excitation sources.展开更多
Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With ...Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With the implementation and emergence of endlessly fascinating UCL features,it is particularly meaningful to understand the photophysical mechanisms inside UCL materials to enable rational subdivision-level structure design,which is however currently far from sufficient.In this work,we take an ordinary upconversion nanoparticle as an example to prove that the UCL decay curves and corresponding lifetimes are indeed a collective response of the entire UCL system to excitations,that exhibits correlated,yet quite different properties from individual ions.A specially developed theoretical random walk model combined with an experimental lifetime control for Yb^(3+)/Er^(3+)UCL demonstrates that ene rgy diffusion principally alters the decay rate.Moreover,the different extent of the influence of energy diffusion on the emissions of ^(2)H_(11/2)/^(4)S_(3/2)(green)and ^(4)F_(9/2)(red)leads to an extremely uncommon crossover comparison of decay rates.This work provides new ideas for understanding decay dynamics and practical UCL lifetime manipulation methods.展开更多
Ultraviolet upconversion photoluminescence materials have great potential in various fields,but the improvement of the upconversion efficiency is challenging.Codoping of Li^(+)is considered as an effective strategy an...Ultraviolet upconversion photoluminescence materials have great potential in various fields,but the improvement of the upconversion efficiency is challenging.Codoping of Li^(+)is considered as an effective strategy and widely used to improve the photoluminescence properties of phosphors.In this paper,Li^(+)is introduced into a Y_(7)O_(6)F_(9):Pr^(3+),Gd^(3+)system.The effect of Li^(+)codoping on the phase purity,crystal structure,micro structure,downshifting and upconversion photo luminescence as well as the decay dynamic of the phosphors was studied.It is revealed that the overall photoluminescence efficiency and the energy transfer efficiency from pr^(3+)to Gd^(3+)are greatly promoted.The downshifting and upconversion photoluminescence increase by 2.58 and 10 times as 6 mol%of Li^(+)is codoped.The photo luminescence decay dynamic study shows that the ^(3)P_(0)state decays slower in the Li^(+)-containing phosphor than the Li^(+)-free one.The improvement of the photoluminescence properties is due to the increase of the crystallinity and the reduce of the quenching center.展开更多
Lanthanide-doped photon-avalanche(PA)upconversion(UC)nanoparticles(NPs),characterized by highly nonlinear optical response,have recently attracted tremendous interest for applications in many frontier areas such as su...Lanthanide-doped photon-avalanche(PA)upconversion(UC)nanoparticles(NPs),characterized by highly nonlinear optical response,have recently attracted tremendous interest for applications in many frontier areas such as super-resolution imaging[1],dynamic photoswitching[2],ultrasensitive optical sensing[3],and high-density optical memory and computing[4].Specifically,the large nonlinearities(N)of PA have fueled the development of low-cost,single-beam super-resolution imaging techniques,offering a√N-fold improvement in spatial resolution[5].Although PA NPs with N plateauing 60s have been developed through energy transfer engineering based on core/shell architecture[6],further enhancement remains challenging.展开更多
Zinc phthalocyanines(ZnPc)are widely recognized as efficient triplet photosensitizers in photodynamic therapy and photocatalysis,owing to their intense absorption in the visible range and long triplet-state lifetimes....Zinc phthalocyanines(ZnPc)are widely recognized as efficient triplet photosensitizers in photodynamic therapy and photocatalysis,owing to their intense absorption in the visible range and long triplet-state lifetimes.However,their application in triplet-triplet annihilation(TTA)upconversion is lacking to date.In this study,we synthesized a new ZnPc photosensitizer,4I-ZnPc,and composed a TTA upconversion system using rubrene as the energy acceptor.Upon photoexcitation at 663 nm,yellow fluorescence from rubrene was observed in deoxygenated dichloromethane,demonstrating TTA upconversion with an anti-Stokes shift of 0.331 eV and a quantum yield of 1.82%(out of the 50%maximum).Using nanosecond transient absorption spectroscopy,we determined the triplet lifetime of 4I-ZnPc,the triplet-triplet energy transfer efficiency,and the fluorescence quantum yield.These measurements provide critical insights into the photophysical processes governing the TTA upconversion system.Our results highlight the potential advantages and limitations of ZnPc as a triplet photosensitizer for TTA upconversion.展开更多
Lanthanide-sensitized upconverting nanoparticles(UCNPs)are widely studied because of their unusual optical characteristics,such as large antenna-generated anti-Stokes shifts,high photostability,and narrow emission ban...Lanthanide-sensitized upconverting nanoparticles(UCNPs)are widely studied because of their unusual optical characteristics,such as large antenna-generated anti-Stokes shifts,high photostability,and narrow emission bandwidths,which can be harnessed for a variety of applications including bioimaging,sensing,information security and high-level anticounterfeiting.The diverse requirements of these applications typically require precise control over upconversion luminescence(UCL).Recently,the concept of energy migration upconversion has emerged as an effective approach to modulate UCL for various lanthanide ions.Moreover,it provides valuable insights into the fundamental comprehension of energy transfer mechanisms on the nanoscale,thereby contributing to the design of efficient lanthanide-sensitized UCNPs and their practical applications.Here we present a comprehensive overview of the latest developments in energy migration upconversion in lanthanide-sensitized nanoparticles for photon upconversion tuning,encompassing design strategies,mechanistic investigations and applications.Additionally,some future prospects in the field of energy migration upconversion are also discussed.展开更多
In this work,rare earth ions(REs)including Yb^(3+)/Er^(3+),Yb^(3+)/Ho^(3+)and Yb^(3+)/Tm^(3+)co-doped manganese oxyfluoride glasses were fabricated using melt quenching method.By fully utilizing the upconversion lumin...In this work,rare earth ions(REs)including Yb^(3+)/Er^(3+),Yb^(3+)/Ho^(3+)and Yb^(3+)/Tm^(3+)co-doped manganese oxyfluoride glasses were fabricated using melt quenching method.By fully utilizing the upconversion luminescence(UCL)of REs and regulating energy transfer between the different energy levels of RE ions and the4T1level of Mn^(2+),the output of UCL was regulated and even pure-red light can be achieved.Moreover,owing to the selective partitioning caused by phase-separation network structure in the oxyfluoride glass,the UCL intensity of glasses annealed for 72 h is significantly enhanced 58 times compared to the rapidly quenched samples.展开更多
Lanthanide-doped upconversion nanoparticles exhibit unique optical properties,enabling the conversion of low-energy photons into high-energy ones.This capability has facilitated their extensive application in fields s...Lanthanide-doped upconversion nanoparticles exhibit unique optical properties,enabling the conversion of low-energy photons into high-energy ones.This capability has facilitated their extensive application in fields such as bioimaging and information security.Traditional research has primarily focused on steady-state characteristics,with strategies such as core-shell structural design,ion doping,and surface passivation being employed to achieve high-brightness luminescence and color tuning.Over the past decade,the study of non-steady-state characteristics has emerged as a research hotspot and has introduced a new dimension for the dynamic con-trol of luminescence.This review systematically surveys the mechanisms,manipulation strategies,and charac-terization methods of non-steady-state upconversion luminescence and provides an overview of the latest advancements in its applications,including multi-dimensional anti-counterfeiting,full-color volumetric display,velocimetry,photonic coding,and logic operation.Furthermore,this review analyzes the current limitations in studying the non-steady-state characteristics of lanthanide-doped fluoride nanostructures and offers perspectives on future development directions.Collectively,these efforts provide a comprehensive framework of knowledge for the field and lay the foundation for further development and expansion of non-steady-state upconversion technologies.We anticipate that this review will provide fundamental insights and guidance for manipulating upconversion properties,thereby further promoting their applications and advancing non-steady-state upcon-version technologies.展开更多
Organic afterglow materials hold significant potential for applications in information storage,anticounterfeiting,and biological imaging.However,studies on afterglow materials capable of ultra-wide range excitation an...Organic afterglow materials hold significant potential for applications in information storage,anticounterfeiting,and biological imaging.However,studies on afterglow materials capable of ultra-wide range excitation and emission simultaneously are limited.To enhance the practicality of strong emission single-component organic afterglow systems,overcoming the constraints of crystalline or other rigid environments is essential.We have developed solid-state dual-persistent thermally activated delayed fluorescence(TADF)and room temperature phosphorescence(RTP)emissions spanning yellow to red under visible light excitation,utilizing a single-molecule terminal group regulation strategy.The RTP lifetime extends from 4.19 ms to 399.70 ms.These afterglow materials exhibit an ultra-wide absorption range from 200 nm to 800 nm,rendering them capable of being excited by both sunlight simulator and nearinfrared radiation.The upconversion phosphorescence lifetime under 808 nm excitation reaches 13.72μs.The double persistent emission of these compounds is temperature-sensitive.Moreover,following grinding or heat treatment,accompanied by extensive afterglow color conversion due to planarization of excited state conformations and additional efficient kRIsc generation.In addition,the amorphous state post melt annealing facilitates the afterglow transition from yellow to green.Crucially,these compounds also maintain stable ultra-long afterglow emission in aqueous and acid-base environments.Overall,we have successfully developed a series of single-component intelligent luminescent materials that demonstrate significant benefits,including dual TADF and RTP emissions,adjustable afterglow lifetimes,a broad range of excitation and emission wavelengths,multi-modal luminescence not restricted to crystalline states,and robust afterglow performance in challenging environments,setting the stage for the practical deployment of afterglow materials in engineering applications,the upconversion afterglow emission also holds promising potential for applications in the field of biological imaging.展开更多
Mid-infrared(MIR)spectral imaging enables precise target identification and analysis by capturing rich chemical fingerprints,which calls for high-sensitivity broadband MIR imagers at room temperature.Here,we devise an...Mid-infrared(MIR)spectral imaging enables precise target identification and analysis by capturing rich chemical fingerprints,which calls for high-sensitivity broadband MIR imagers at room temperature.Here,we devise and implement a continuous-wave pumping MIR upconversion imaging system based on externalcavity enhancement,which favors a large field of view,a low cavity loss,and a high spectral resolution.The involved optical cavity is constructed in an integrated fashion by utilizing one crystal facet as a cavity mirror,which allows a 43-fold power enhancement for the single-longitudinal-mode pump at 1064 nm.In combination with the chirped-poling crystal design,high-fidelity and wide-field spectral imaging mapping is permitted to facilitate an acceptance angle of up to 28.5 deg over a spectral coverage of 2.5 to 5μm.Moreover,a thermal locking approach is used to stabilize the cavity at high-power operation,eliminating active feedback and ensuring long-term stability.A proof-of-principle demonstration is presented to showcase real-time observation of CO_(2)gas injection dynamics.The implemented MIR upconversion imager features wide-field operation,high detection sensitivity,and compact footprint,which would benefit subsequent applications,including environment monitoring,gas leakage inspection,and medical diagnostics.展开更多
Lutetium oxide nanocrystals codoped with Tm3+and Yb3+were synthesized by the reverse-like co-precipitation method,using ammonium hydrogen carbonate as precipitant.Effects of the Tm3+,Yb3+molar fractions and calcinatio...Lutetium oxide nanocrystals codoped with Tm3+and Yb3+were synthesized by the reverse-like co-precipitation method,using ammonium hydrogen carbonate as precipitant.Effects of the Tm3+,Yb3+molar fractions and calcination temperature on the structural and upconversion luminescent properties of the Lu2O3 nanocrystals were investigated.The XRD results show that all the prepared nanocrystals can be readily indexed to pure cubic phase of Lu2O3 and indicate good crystallinity.The experimental results show that concentration quenching occurs when the mole fraction of Tm3+is above 0.2%.The optimal Tm3+and Yb3+doped molar fractions are 0.2%and 2%,respectively.The strong blue(490 nm)and the weak red(653 nm)emissions from the prepared nanocrystals were observed under 980 nm laser excitation,and attributed to the 1G4→3H6 and IG4→3F4 transitions of Tm3+,respectively.Power-dependent study reveals that the 1G4 levels of Tm3+can be populated by three-step energy transfer process.The upconversion emission intensities of 490 nm and 653 nm increase gradually with the increase of calcination temperature.The enhancement of the upconversion luminescence is suggested to be the consequence of reducing number of OH-groups and the enlarged nanoerystal size.展开更多
Lateral flow immunoassays(LFIAs)are low-cost,rapid,and easy to use for pointof-care testing(POCT),but the majority of the available LFIA tests are indicative,rather than quantitative,and their sensitivity in antigen t...Lateral flow immunoassays(LFIAs)are low-cost,rapid,and easy to use for pointof-care testing(POCT),but the majority of the available LFIA tests are indicative,rather than quantitative,and their sensitivity in antigen tests are usually limited at the nanogram range,which is primarily due to the passive capillary fluidics through nitrocellulose membranes,often associated with non-specific bindings and high background noise.To overcome this challenge,we report a Beads-on-a-Tip design by replacing nitrocellulose membranes with a pipette tip loaded with magnetic beads.The beads are pre-conjugated with capture antibodies that support a typical sandwich immunoassay.This design enriches the low-abundant antigen proteins and allows an active washing process to significantly reduce non-specific bindings.To further improve the detection sensitivity,we employed upconversion nanoparticles(UCNPs)as luminescent reporters and SARS-CoV-2 spike(S)antigen as a model analyte to benchmark the performance of this design against our previously reported methods.We found that the key to enhance the immunocomplex formation and signal-to-noise ratio lay in optimizing incubation time and the UCNP-to-bead ratio.We therefore successfully demonstrated that the new method can achieve a very large dynamic range from 500 fg/mL to 10μg/mL,across over 7 digits,and a limit of detection of 706 fg/mL,nearly another order of magnitude lower than the best reported LFIA using UCNPs in COVID-19 spike antigen detection.Our system offers a promising solution for ultra-sensitive and quantitative POCT diagnostics.展开更多
The study of target proteins is crucial for understanding molecular interactions and developing analytical platforms,therapeutic agents and functional tools.Herein,we present a novel nanoplatform activated by near-inf...The study of target proteins is crucial for understanding molecular interactions and developing analytical platforms,therapeutic agents and functional tools.Herein,we present a novel nanoplatform activated by near-infrared(NIR) light for triple-modal proteins study,which enabling target protein labeling,enrichment and visualization.Azido-naphthalimide-coated upconversion nanoparticles(UCNPs) serve as NIR light-responsive nanoplatforms,showing promising applications in studying interactions between various bioactive molecules and proteins in living systems.Under NIR light irradiation,azido-naphthalimides are activated by ultraviolet(UV) and blue light emitted from UCNPs and the resulting amino-naphthalimides intermediate not only crosslink nearby target proteins but also enable imaging performance.We demonstrate that this nanoplatform is capable of selective protein labeling and imaging in complex protein environments,achieving specific labeling and imaging of both intracellular and extracellular proteins in mammalian cells as well as bacteria.Furthermore,in vivo protein labeling has been achieved using this novel NIR light-activatable nanoplatform.This technique will open new avenues for discoveries and mechanistic interrogation in chemical biology.展开更多
Erbium-doped BaTiO3 films on LaNiO3/Si substrates were fabricated by sol-gel method. The crystalline structure, morphologies and upconversion （UC） luminescence properties of films were respectively investigated by X...Erbium-doped BaTiO3 films on LaNiO3/Si substrates were fabricated by sol-gel method. The crystalline structure, morphologies and upconversion （UC） luminescence properties of films were respectively investigated by X-ray diffraction （XRD）, atomic force microcopy （AFM） and photoluminescence （PL）. The results indicate that both of the microstructure and luminescence are found to be dependent on Er^3＋ substituting sites. The samples with A-site substitution have smaller lattice constants, larger grains and smoother surface than those with B-site substitution. The photoluminescence spectra show that both of the samples have two stronger green emission bands centered at 528 and 548 nm and a weak red emission band centered at 673 nm, which correspond to the relaxation of Er^3＋ from ^2H11/2, ^4S3/2, and ^4F9/2 levels to the ground level ^4I15/2, respectively. Compared with B-site doped films, A-site doped films have a stronger integrated intensity of green emissions and a weaker relative intensity of red emissions. The differences could be explained by the crystalline quality and cross relaxation （CR） process.展开更多
Rare earth doped upconversion nanoparticles can be considered as the spice of research in the field of luminescence nanomaterials due to their unique optical properties such as near-infrared excitation.Enormous works ...Rare earth doped upconversion nanoparticles can be considered as the spice of research in the field of luminescence nanomaterials due to their unique optical properties such as near-infrared excitation.Enormous works have been reported about biomedical applications of 980 nm excited and Yb^3+-sensitized upconversion nanoparticles.However,980 nm excitation wavelength overlaps with the absorption band of water molecules in the biological environment,leading to overheating effect that can induce thermal damages of normal cells and tissues.Recently,Nd^3+-sensitized upconversion nanoparticles which can be excited with 808 nm has been widely investigated as alternative nanoparticles that can surmount this issue of overheating effect.Even though Nd^3+-sensitized upconversion nanoparticles can reduce the overheating effect by 20 fold as compared to Yb^3+-sensitized counterpart,there are several factors that reduce the upconversion luminescence intensity.In this review article,photon energy harvesting and transferring mechanisms in Nd^3+,Yb^3+and emitter ions co-doped upconversion nanoparticles under 808 nm excitation are briefly discussed.Factors that affect upconversion luminescence intensity and quantum yield of Nd^3+-sensitized upconversion nanoparticles are also addressed.Besides,some of the important strategies that have been recently utilized to boost upconversion luminescence intensity of Nd^3+sensitized upco nversion nanoparticles are tho roughly summarized.Lastly,the future challenges in the area and our perspectives are in sight.展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),"Qinglan Project"Young and Middle-aged Academic Leaders Program of Jiangsu Province,and the National Natural Science Foundation of China(General Program).
文摘The enhancement of the intensity of red upconversion(UC)emission has significant implications for biological applications.In KZnF_(3):Yb^(3+),Er^(3+)which inherently produces high-purity red emission,the introduction of Fe^(3+)markedly improves the UC intensity by a factor of 13.The mechanism behind the enhanced UC red luminescence is deduced to originate from the Yb^(3+)-Fe^(3+)dimer,as determined by first principle calculation and analysis of UC luminescence properties.The thermometry performance,based on splitting peaks of red emission,demonstrated enhanced temperature sensitivity at lower ranges.Exploring the photothermal properties,it was observed that temperature exhibited a linear correlation with pump power under a 980 nm laser,achieving levels up to 48℃.This temperature range is ideal for applications in mild photothermal therapy(MPTT).This work elucidates the material’s potential in advanced biological applications,merging optical thermometry and photothermics,indicating its multifunctional utility.
文摘4-Nonylphenol(NP)is a kind of estrogen belonging to the endocrine disrupter,widely used in various agricultural and industrial goods.However,extensive use of NP with direct release to environment poses high risks to both human health and ecosystems.Herein,for the first time,we developed near-infrared(NIR)responsive upconversion luminescence nanosensor for NP detection.The Förster resonance energy transfer based upconversion nanoparticles(UCNPs)-graphene oxide sensor offers highly selective and sensitive detection of NP in linear ranges of 5−200 ng/mL and 200−1000 ng/mL under 980 nm and 808 nm excitation,respectively,with LOD at 4.2 ng/mL.The sensors were successfully tested for NP detection in real liquid milk samples with excellent recovery results.The rare-earth fluoride based upconversion luminescence nanosensor with NIR excitation wavelength,holds promise for sensing food,environmental,and biological samples due to their high sensitivity,specific recognition,low LOD,negligible autofluorescence,along with the deep penetration of NIR excitation sources.
基金Project supported by the National Natural Science Foundation of China(62105235,62205035)the Scientific Research Project of Tianjin Education Commission(2022KJ060)+1 种基金Qinglan Project of Jiangsu Province of ChinaNatural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJD350001)。
文摘Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With the implementation and emergence of endlessly fascinating UCL features,it is particularly meaningful to understand the photophysical mechanisms inside UCL materials to enable rational subdivision-level structure design,which is however currently far from sufficient.In this work,we take an ordinary upconversion nanoparticle as an example to prove that the UCL decay curves and corresponding lifetimes are indeed a collective response of the entire UCL system to excitations,that exhibits correlated,yet quite different properties from individual ions.A specially developed theoretical random walk model combined with an experimental lifetime control for Yb^(3+)/Er^(3+)UCL demonstrates that ene rgy diffusion principally alters the decay rate.Moreover,the different extent of the influence of energy diffusion on the emissions of ^(2)H_(11/2)/^(4)S_(3/2)(green)and ^(4)F_(9/2)(red)leads to an extremely uncommon crossover comparison of decay rates.This work provides new ideas for understanding decay dynamics and practical UCL lifetime manipulation methods.
基金supported by the National Natural Science Foundation of China(51701091,12004148,12104199,12204216)the Natural Science Foundation of Shandong Province(ZR2021QA057)+1 种基金the Shandong Province Science and Technology Small and Medium Sized Enterprise Innovation Ability Enhancement Project(2023TSGC0352)the Innovation Team of Higher Educational Science and Technology Program of Shandong Province(2019KJA025)。
文摘Ultraviolet upconversion photoluminescence materials have great potential in various fields,but the improvement of the upconversion efficiency is challenging.Codoping of Li^(+)is considered as an effective strategy and widely used to improve the photoluminescence properties of phosphors.In this paper,Li^(+)is introduced into a Y_(7)O_(6)F_(9):Pr^(3+),Gd^(3+)system.The effect of Li^(+)codoping on the phase purity,crystal structure,micro structure,downshifting and upconversion photo luminescence as well as the decay dynamic of the phosphors was studied.It is revealed that the overall photoluminescence efficiency and the energy transfer efficiency from pr^(3+)to Gd^(3+)are greatly promoted.The downshifting and upconversion photoluminescence increase by 2.58 and 10 times as 6 mol%of Li^(+)is codoped.The photo luminescence decay dynamic study shows that the ^(3)P_(0)state decays slower in the Li^(+)-containing phosphor than the Li^(+)-free one.The improvement of the photoluminescence properties is due to the increase of the crystallinity and the reduce of the quenching center.
基金the National Natural Science Foundation of China(Nos.12474418,U22A20398,22135008)the Natural Science Foundation of Fujian Province(No.2024J010038).
文摘Lanthanide-doped photon-avalanche(PA)upconversion(UC)nanoparticles(NPs),characterized by highly nonlinear optical response,have recently attracted tremendous interest for applications in many frontier areas such as super-resolution imaging[1],dynamic photoswitching[2],ultrasensitive optical sensing[3],and high-density optical memory and computing[4].Specifically,the large nonlinearities(N)of PA have fueled the development of low-cost,single-beam super-resolution imaging techniques,offering a√N-fold improvement in spatial resolution[5].Although PA NPs with N plateauing 60s have been developed through energy transfer engineering based on core/shell architecture[6],further enhancement remains challenging.
基金supported by the National Natural Science Foundation of China(Nos.22473104 and 22403086)support of the China Postdoctoral Science Foundation(No.2023M733378).
文摘Zinc phthalocyanines(ZnPc)are widely recognized as efficient triplet photosensitizers in photodynamic therapy and photocatalysis,owing to their intense absorption in the visible range and long triplet-state lifetimes.However,their application in triplet-triplet annihilation(TTA)upconversion is lacking to date.In this study,we synthesized a new ZnPc photosensitizer,4I-ZnPc,and composed a TTA upconversion system using rubrene as the energy acceptor.Upon photoexcitation at 663 nm,yellow fluorescence from rubrene was observed in deoxygenated dichloromethane,demonstrating TTA upconversion with an anti-Stokes shift of 0.331 eV and a quantum yield of 1.82%(out of the 50%maximum).Using nanosecond transient absorption spectroscopy,we determined the triplet lifetime of 4I-ZnPc,the triplet-triplet energy transfer efficiency,and the fluorescence quantum yield.These measurements provide critical insights into the photophysical processes governing the TTA upconversion system.Our results highlight the potential advantages and limitations of ZnPc as a triplet photosensitizer for TTA upconversion.
基金supported by Senior Talent Fund of Jiangsu University(No.5501310021)China Postdoctoral Science Foundation(No.2023M741419)+1 种基金the Young Elite Scientist Sponsorship Program by ZJAST(No.G301310002)Research Fund for International Scientists(No.22350710187).
文摘Lanthanide-sensitized upconverting nanoparticles(UCNPs)are widely studied because of their unusual optical characteristics,such as large antenna-generated anti-Stokes shifts,high photostability,and narrow emission bandwidths,which can be harnessed for a variety of applications including bioimaging,sensing,information security and high-level anticounterfeiting.The diverse requirements of these applications typically require precise control over upconversion luminescence(UCL).Recently,the concept of energy migration upconversion has emerged as an effective approach to modulate UCL for various lanthanide ions.Moreover,it provides valuable insights into the fundamental comprehension of energy transfer mechanisms on the nanoscale,thereby contributing to the design of efficient lanthanide-sensitized UCNPs and their practical applications.Here we present a comprehensive overview of the latest developments in energy migration upconversion in lanthanide-sensitized nanoparticles for photon upconversion tuning,encompassing design strategies,mechanistic investigations and applications.Additionally,some future prospects in the field of energy migration upconversion are also discussed.
基金Project supported by National Natural Science Foundation of China(62305244,62374112,62105078)Shandong Province Natural Science Foundation(ZR2021QE060,ZR2021QF009)+1 种基金Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2022QNRC001)Youth Science and Technology Innovation Team of Shandong Province Institution of Higher Learning(2022KJ258)。
文摘In this work,rare earth ions(REs)including Yb^(3+)/Er^(3+),Yb^(3+)/Ho^(3+)and Yb^(3+)/Tm^(3+)co-doped manganese oxyfluoride glasses were fabricated using melt quenching method.By fully utilizing the upconversion luminescence(UCL)of REs and regulating energy transfer between the different energy levels of RE ions and the4T1level of Mn^(2+),the output of UCL was regulated and even pure-red light can be achieved.Moreover,owing to the selective partitioning caused by phase-separation network structure in the oxyfluoride glass,the UCL intensity of glasses annealed for 72 h is significantly enhanced 58 times compared to the rapidly quenched samples.
基金supported by National Natural Science Foundation of China(52272141,52572155)Natural Science Foundation of Fujian Province(2024J02014,2021J01190).
文摘Lanthanide-doped upconversion nanoparticles exhibit unique optical properties,enabling the conversion of low-energy photons into high-energy ones.This capability has facilitated their extensive application in fields such as bioimaging and information security.Traditional research has primarily focused on steady-state characteristics,with strategies such as core-shell structural design,ion doping,and surface passivation being employed to achieve high-brightness luminescence and color tuning.Over the past decade,the study of non-steady-state characteristics has emerged as a research hotspot and has introduced a new dimension for the dynamic con-trol of luminescence.This review systematically surveys the mechanisms,manipulation strategies,and charac-terization methods of non-steady-state upconversion luminescence and provides an overview of the latest advancements in its applications,including multi-dimensional anti-counterfeiting,full-color volumetric display,velocimetry,photonic coding,and logic operation.Furthermore,this review analyzes the current limitations in studying the non-steady-state characteristics of lanthanide-doped fluoride nanostructures and offers perspectives on future development directions.Collectively,these efforts provide a comprehensive framework of knowledge for the field and lay the foundation for further development and expansion of non-steady-state upconversion technologies.We anticipate that this review will provide fundamental insights and guidance for manipulating upconversion properties,thereby further promoting their applications and advancing non-steady-state upcon-version technologies.
基金financially supported by the National Natural Science Foundation of China(No.21871122)。
文摘Organic afterglow materials hold significant potential for applications in information storage,anticounterfeiting,and biological imaging.However,studies on afterglow materials capable of ultra-wide range excitation and emission simultaneously are limited.To enhance the practicality of strong emission single-component organic afterglow systems,overcoming the constraints of crystalline or other rigid environments is essential.We have developed solid-state dual-persistent thermally activated delayed fluorescence(TADF)and room temperature phosphorescence(RTP)emissions spanning yellow to red under visible light excitation,utilizing a single-molecule terminal group regulation strategy.The RTP lifetime extends from 4.19 ms to 399.70 ms.These afterglow materials exhibit an ultra-wide absorption range from 200 nm to 800 nm,rendering them capable of being excited by both sunlight simulator and nearinfrared radiation.The upconversion phosphorescence lifetime under 808 nm excitation reaches 13.72μs.The double persistent emission of these compounds is temperature-sensitive.Moreover,following grinding or heat treatment,accompanied by extensive afterglow color conversion due to planarization of excited state conformations and additional efficient kRIsc generation.In addition,the amorphous state post melt annealing facilitates the afterglow transition from yellow to green.Crucially,these compounds also maintain stable ultra-long afterglow emission in aqueous and acid-base environments.Overall,we have successfully developed a series of single-component intelligent luminescent materials that demonstrate significant benefits,including dual TADF and RTP emissions,adjustable afterglow lifetimes,a broad range of excitation and emission wavelengths,multi-modal luminescence not restricted to crystalline states,and robust afterglow performance in challenging environments,setting the stage for the practical deployment of afterglow materials in engineering applications,the upconversion afterglow emission also holds promising potential for applications in the field of biological imaging.
基金supported by the Shanghai Pilot Program for Basic Research (Grant No. TQ20220104)the National Natural Science Foundation of China (Grant Nos. 62175064, 62235019, and 62035005)+4 种基金the Innovation Program for Quantum Science and Technology (Grant No. 2023ZD0301000)the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01)the Natural Science Foundation of Chongqing (Grant Nos. CSTB2023NSCQ-JQX0011 and CSTB2022TIAD-DEX0036)the Fundamental Research Funds for the Central Universitiesthe China Postdoctoral Science Foundation (Grant No. 2024M760918)
文摘Mid-infrared(MIR)spectral imaging enables precise target identification and analysis by capturing rich chemical fingerprints,which calls for high-sensitivity broadband MIR imagers at room temperature.Here,we devise and implement a continuous-wave pumping MIR upconversion imaging system based on externalcavity enhancement,which favors a large field of view,a low cavity loss,and a high spectral resolution.The involved optical cavity is constructed in an integrated fashion by utilizing one crystal facet as a cavity mirror,which allows a 43-fold power enhancement for the single-longitudinal-mode pump at 1064 nm.In combination with the chirped-poling crystal design,high-fidelity and wide-field spectral imaging mapping is permitted to facilitate an acceptance angle of up to 28.5 deg over a spectral coverage of 2.5 to 5μm.Moreover,a thermal locking approach is used to stabilize the cavity at high-power operation,eliminating active feedback and ensuring long-term stability.A proof-of-principle demonstration is presented to showcase real-time observation of CO_(2)gas injection dynamics.The implemented MIR upconversion imager features wide-field operation,high detection sensitivity,and compact footprint,which would benefit subsequent applications,including environment monitoring,gas leakage inspection,and medical diagnostics.
基金Foundation item:Projects(10704090,10774140,11047147)supported by the National Natural Science Foundation of ChinaProjects(KJ090514,KJTD201016)supported by the Natural Science Foundation of Chongqing Municipal Education Commission,China
文摘Lutetium oxide nanocrystals codoped with Tm3+and Yb3+were synthesized by the reverse-like co-precipitation method,using ammonium hydrogen carbonate as precipitant.Effects of the Tm3+,Yb3+molar fractions and calcination temperature on the structural and upconversion luminescent properties of the Lu2O3 nanocrystals were investigated.The XRD results show that all the prepared nanocrystals can be readily indexed to pure cubic phase of Lu2O3 and indicate good crystallinity.The experimental results show that concentration quenching occurs when the mole fraction of Tm3+is above 0.2%.The optimal Tm3+and Yb3+doped molar fractions are 0.2%and 2%,respectively.The strong blue(490 nm)and the weak red(653 nm)emissions from the prepared nanocrystals were observed under 980 nm laser excitation,and attributed to the 1G4→3H6 and IG4→3F4 transitions of Tm3+,respectively.Power-dependent study reveals that the 1G4 levels of Tm3+can be populated by three-step energy transfer process.The upconversion emission intensities of 490 nm and 653 nm increase gradually with the increase of calcination temperature.The enhancement of the upconversion luminescence is suggested to be the consequence of reducing number of OH-groups and the enlarged nanoerystal size.
基金financially supported by ARC Linkage project(LP210200642)ARC Center of Excellence for Quantum Biotechnology(grant no.CE230100021)+1 种基金National Health and Medical Research Council Investigator Fellowship—(grant no.APP2017499)Chan Zuckerberg Initiative Deep Tissue Imaging Phase 2(grant no.DT12-0000000182).
文摘Lateral flow immunoassays(LFIAs)are low-cost,rapid,and easy to use for pointof-care testing(POCT),but the majority of the available LFIA tests are indicative,rather than quantitative,and their sensitivity in antigen tests are usually limited at the nanogram range,which is primarily due to the passive capillary fluidics through nitrocellulose membranes,often associated with non-specific bindings and high background noise.To overcome this challenge,we report a Beads-on-a-Tip design by replacing nitrocellulose membranes with a pipette tip loaded with magnetic beads.The beads are pre-conjugated with capture antibodies that support a typical sandwich immunoassay.This design enriches the low-abundant antigen proteins and allows an active washing process to significantly reduce non-specific bindings.To further improve the detection sensitivity,we employed upconversion nanoparticles(UCNPs)as luminescent reporters and SARS-CoV-2 spike(S)antigen as a model analyte to benchmark the performance of this design against our previously reported methods.We found that the key to enhance the immunocomplex formation and signal-to-noise ratio lay in optimizing incubation time and the UCNP-to-bead ratio.We therefore successfully demonstrated that the new method can achieve a very large dynamic range from 500 fg/mL to 10μg/mL,across over 7 digits,and a limit of detection of 706 fg/mL,nearly another order of magnitude lower than the best reported LFIA using UCNPs in COVID-19 spike antigen detection.Our system offers a promising solution for ultra-sensitive and quantitative POCT diagnostics.
基金supported by the National Natural Science Foundation of China (No.22007008)the LiaoNing Revitalization Talents Program (No.XLYC1907021)the Fundamental Research Funds for the Central Universities (Nos.DUT23YG120,DUT19RC(3)009)。
文摘The study of target proteins is crucial for understanding molecular interactions and developing analytical platforms,therapeutic agents and functional tools.Herein,we present a novel nanoplatform activated by near-infrared(NIR) light for triple-modal proteins study,which enabling target protein labeling,enrichment and visualization.Azido-naphthalimide-coated upconversion nanoparticles(UCNPs) serve as NIR light-responsive nanoplatforms,showing promising applications in studying interactions between various bioactive molecules and proteins in living systems.Under NIR light irradiation,azido-naphthalimides are activated by ultraviolet(UV) and blue light emitted from UCNPs and the resulting amino-naphthalimides intermediate not only crosslink nearby target proteins but also enable imaging performance.We demonstrate that this nanoplatform is capable of selective protein labeling and imaging in complex protein environments,achieving specific labeling and imaging of both intracellular and extracellular proteins in mammalian cells as well as bacteria.Furthermore,in vivo protein labeling has been achieved using this novel NIR light-activatable nanoplatform.This technique will open new avenues for discoveries and mechanistic interrogation in chemical biology.
基金Project (2009AA035002) supported by the High-tech Research and Development Program of China
文摘Erbium-doped BaTiO3 films on LaNiO3/Si substrates were fabricated by sol-gel method. The crystalline structure, morphologies and upconversion （UC） luminescence properties of films were respectively investigated by X-ray diffraction （XRD）, atomic force microcopy （AFM） and photoluminescence （PL）. The results indicate that both of the microstructure and luminescence are found to be dependent on Er^3＋ substituting sites. The samples with A-site substitution have smaller lattice constants, larger grains and smoother surface than those with B-site substitution. The photoluminescence spectra show that both of the samples have two stronger green emission bands centered at 528 and 548 nm and a weak red emission band centered at 673 nm, which correspond to the relaxation of Er^3＋ from ^2H11/2, ^4S3/2, and ^4F9/2 levels to the ground level ^4I15/2, respectively. Compared with B-site doped films, A-site doped films have a stronger integrated intensity of green emissions and a weaker relative intensity of red emissions. The differences could be explained by the crystalline quality and cross relaxation （CR） process.
基金Projects supported by the National Natural Science Foundation of China(21571125,51872183,51672171)National Key R&D Program of China(2016YFE0114800)
文摘Rare earth doped upconversion nanoparticles can be considered as the spice of research in the field of luminescence nanomaterials due to their unique optical properties such as near-infrared excitation.Enormous works have been reported about biomedical applications of 980 nm excited and Yb^3+-sensitized upconversion nanoparticles.However,980 nm excitation wavelength overlaps with the absorption band of water molecules in the biological environment,leading to overheating effect that can induce thermal damages of normal cells and tissues.Recently,Nd^3+-sensitized upconversion nanoparticles which can be excited with 808 nm has been widely investigated as alternative nanoparticles that can surmount this issue of overheating effect.Even though Nd^3+-sensitized upconversion nanoparticles can reduce the overheating effect by 20 fold as compared to Yb^3+-sensitized counterpart,there are several factors that reduce the upconversion luminescence intensity.In this review article,photon energy harvesting and transferring mechanisms in Nd^3+,Yb^3+and emitter ions co-doped upconversion nanoparticles under 808 nm excitation are briefly discussed.Factors that affect upconversion luminescence intensity and quantum yield of Nd^3+-sensitized upconversion nanoparticles are also addressed.Besides,some of the important strategies that have been recently utilized to boost upconversion luminescence intensity of Nd^3+sensitized upco nversion nanoparticles are tho roughly summarized.Lastly,the future challenges in the area and our perspectives are in sight.
