We investigate the dynamics of resonant Raman scattering in the course of the frequency de- tuning. The dephasing in the time domain makes the scattering fast when the photon energy is tuned from the absorption resona...We investigate the dynamics of resonant Raman scattering in the course of the frequency de- tuning. The dephasing in the time domain makes the scattering fast when the photon energy is tuned from the absorption resonance. This makes frequency detuning to act as a camera shutter with a regulated scattering duration and provides a practical tool of controlling the scattering time in ordinary stationary measurements. The theory is applied to resonant Raman spectra of a couple of few-mode model systems and to trans-1,3,5-hexatriene and guanine-cytosine （G-C） Watson-Crick base pairs （DNA） molecules. Besides some particular physical effects, the regime of fast scattering leads to a simplification of the spectrum as well as to the scattering theory itself. Strong overtones appear in the Raman spectra when the photon frequency is tuned in the resonant region, while in the mode of fast scattering, the overtones are gradually quenched when the photon frequency is tuned more than one vibra- tional quantum below the first absorption resonance. The detuning from the resonant region thus leads to a strong purification of the Raman spectrum from the contamination by higher overtones and soft modes and purifies the spectrum also in terms of avoidance of dissociation and interfering fluorescence decay of the resonant state. This makes frequency detuning a very useful practical tool in the analysis of the resonant Raman spectra of complex systems and considerably improves the prospects for using the Raman effect for detection of foreign substances at ultra-low concentrations.展开更多
Optically responsive composite materials hold significant promise for in vivo diagnostics and targeted therapies.Rare-earthdoped upconversion nanoparticles(UCNPs),renowned for their unique luminescence properties,larg...Optically responsive composite materials hold significant promise for in vivo diagnostics and targeted therapies.Rare-earthdoped upconversion nanoparticles(UCNPs),renowned for their unique luminescence properties,large anti-Stokes shift,excellent biocompatibility,and deep tissue penetration,have emerged as highly promising candidates for advanced phototherapy in biological systems.This review first explores the fundamental mechanisms of upconversion luminescence,as well as synthesis,surface modification,and design strategies to brighten upconversion.It then highlights recent advances and key applications of UCNPs in biological therapy,including upconversion-mediated phototherapy,multimodal therapeutic approaches,and image-guided therapy and surgery.Finally,it discusses the current challenges and opportunities in both fundamental research and clinical translation,providing theoretical insights and practical guidance to support the broader application of UCNPs in biological therapy and clinical medicine.展开更多
Since selective detection of multiple narrow spectral bands in the near-infrared(NIR)region still poses a fundamental challenge,we have,in this work,developed NIR photodetectors(PDs)using photon upconversion nanocryst...Since selective detection of multiple narrow spectral bands in the near-infrared(NIR)region still poses a fundamental challenge,we have,in this work,developed NIR photodetectors(PDs)using photon upconversion nanocrystals(UCNCs)combined with perovskite films.To conquer the relatively high pumping threshold of UCNCs,we designed a novel cascade optical field modulation strategy to boost upconversion luminescence(UCL)by cascading the superlensing effect of dielectric microlens arrays and the plasmonic effect of gold nanorods,which readily leads to a UCL enhancement by more than four orders of magnitude under weak light irradiation.By accommodating multiple optically active lanthanide ions in a core-shell-shell hierarchical architecture,developed PDs on top of this structure can detect three well-separated narrow bands in the NIR region,i.e.,those centered at 808,980,and 1540 nm.Due to the large UCL enhancement,the obtained PDs demonstrate extremely high responsivities of 30.73,23.15,and 12.20 AW^(−1) and detectivities of 5.36,3.45,and 1.91×10^(11) Jones for 808,980,and 1540 nm light detection,respectively,together with short response times in the range of 80-120 ms.Moreover,we demonstrate for the first time that the response to the excitation modulation frequency of a PD can be employed to discriminate the incident light wavelength.We believe that our work provides novel insight for developing NIR PDs and that it can spur the development of other applications using upconversion nanotechnology.展开更多
The self-assembling properties, stability, and dynamics of hybrid nanocarriers （gold nanoparticles （AuNPs） functionalized with cysteine-based peptides） in solution are studied through a series of classical molecul...The self-assembling properties, stability, and dynamics of hybrid nanocarriers （gold nanoparticles （AuNPs） functionalized with cysteine-based peptides） in solution are studied through a series of classical molecular dynamics simulations based on a recently parametrized reactive force field. The results reveal, at the atomic level, all the details regarding the peptide adsorption mechanisms, nanoparticle stabilization, aggregation, and sintering. The data confirm and explain the experimental findings and disclose aspects that cannot be scrutinized by experiments. The biomolecules are both chemisorbed and physisorbed; self-interactions of the adsorbates and formation of stable networks of inter- connected molecules on the AuNP surfaces limit substrate reconstructions, protect the AuNPs from the action of the solvent, and prevent direct interactions of the gold surfaces. The possibility of agglomeration of the functionalized nanoparticles, compared with the sintering of the bare supports in a water solution, is demonstrated through relatively long simulations and fast steered dynamics. The analysis of the trajectories reveals that the AuNPs were well stabilized by the peptides. This prevented particle sintering and kept the particles far apart; however, part of their chains could form interconnections （crosslinks） between neighboring gold vehicles. The excellent agreement of these results with the literature confirm the reliability of the method and its potential application to the modeling of more complex materials relevant to the biomedical sector.展开更多
文摘We investigate the dynamics of resonant Raman scattering in the course of the frequency de- tuning. The dephasing in the time domain makes the scattering fast when the photon energy is tuned from the absorption resonance. This makes frequency detuning to act as a camera shutter with a regulated scattering duration and provides a practical tool of controlling the scattering time in ordinary stationary measurements. The theory is applied to resonant Raman spectra of a couple of few-mode model systems and to trans-1,3,5-hexatriene and guanine-cytosine （G-C） Watson-Crick base pairs （DNA） molecules. Besides some particular physical effects, the regime of fast scattering leads to a simplification of the spectrum as well as to the scattering theory itself. Strong overtones appear in the Raman spectra when the photon frequency is tuned in the resonant region, while in the mode of fast scattering, the overtones are gradually quenched when the photon frequency is tuned more than one vibra- tional quantum below the first absorption resonance. The detuning from the resonant region thus leads to a strong purification of the Raman spectrum from the contamination by higher overtones and soft modes and purifies the spectrum also in terms of avoidance of dissociation and interfering fluorescence decay of the resonant state. This makes frequency detuning a very useful practical tool in the analysis of the resonant Raman spectra of complex systems and considerably improves the prospects for using the Raman effect for detection of foreign substances at ultra-low concentrations.
基金supported by the grants from the National Natural Science Foundation of China(Grant Nos.52272270,51972084)the Key Technology Research and Industrialization Demonstration Project of Qingdao(Grant No.25-1-1-gjgg-1-gx)+3 种基金the Outstanding Young Scholars Project of the Natural Science Foundation of Heilongjiang Province,China(Grant No.JJ2023JQ0025)the Opening Project of State Key Laboratory of Space Power Sources(Grant No.YF07050123F2531)the Young Scientist Workshop(Harbin Institute of Technology)(Grant No.AUGA5710094420)the Fundamental Research Funds for the Central Universities,China(Grant Nos.AUGA5710052614,HIT.OCEF.2023041).
文摘Optically responsive composite materials hold significant promise for in vivo diagnostics and targeted therapies.Rare-earthdoped upconversion nanoparticles(UCNPs),renowned for their unique luminescence properties,large anti-Stokes shift,excellent biocompatibility,and deep tissue penetration,have emerged as highly promising candidates for advanced phototherapy in biological systems.This review first explores the fundamental mechanisms of upconversion luminescence,as well as synthesis,surface modification,and design strategies to brighten upconversion.It then highlights recent advances and key applications of UCNPs in biological therapy,including upconversion-mediated phototherapy,multimodal therapeutic approaches,and image-guided therapy and surgery.Finally,it discusses the current challenges and opportunities in both fundamental research and clinical translation,providing theoretical insights and practical guidance to support the broader application of UCNPs in biological therapy and clinical medicine.
基金supported by the National Natural Science Foundation of China(Grant Nos.11974143,11874181,61822506,and U1801253)the Special Project of the Province-University Co-constructing Program of Jilin Province(SXGJXX2017-3)+5 种基金support from the Swedish Research Council(VR 2016-03804)the Carl Tryggers Foundation(CTS 18:229)the AForsk Foundation(19-424)the Olle Engkvists Foundation(200-0514)support from the Swedish Research Council(VR 2016-03319)support from the Swedish Foundation for Strategic Research(SSF ITM17-0491).
文摘Since selective detection of multiple narrow spectral bands in the near-infrared(NIR)region still poses a fundamental challenge,we have,in this work,developed NIR photodetectors(PDs)using photon upconversion nanocrystals(UCNCs)combined with perovskite films.To conquer the relatively high pumping threshold of UCNCs,we designed a novel cascade optical field modulation strategy to boost upconversion luminescence(UCL)by cascading the superlensing effect of dielectric microlens arrays and the plasmonic effect of gold nanorods,which readily leads to a UCL enhancement by more than four orders of magnitude under weak light irradiation.By accommodating multiple optically active lanthanide ions in a core-shell-shell hierarchical architecture,developed PDs on top of this structure can detect three well-separated narrow bands in the NIR region,i.e.,those centered at 808,980,and 1540 nm.Due to the large UCL enhancement,the obtained PDs demonstrate extremely high responsivities of 30.73,23.15,and 12.20 AW^(−1) and detectivities of 5.36,3.45,and 1.91×10^(11) Jones for 808,980,and 1540 nm light detection,respectively,together with short response times in the range of 80-120 ms.Moreover,we demonstrate for the first time that the response to the excitation modulation frequency of a PD can be employed to discriminate the incident light wavelength.We believe that our work provides novel insight for developing NIR PDs and that it can spur the development of other applications using upconversion nanotechnology.
文摘The self-assembling properties, stability, and dynamics of hybrid nanocarriers （gold nanoparticles （AuNPs） functionalized with cysteine-based peptides） in solution are studied through a series of classical molecular dynamics simulations based on a recently parametrized reactive force field. The results reveal, at the atomic level, all the details regarding the peptide adsorption mechanisms, nanoparticle stabilization, aggregation, and sintering. The data confirm and explain the experimental findings and disclose aspects that cannot be scrutinized by experiments. The biomolecules are both chemisorbed and physisorbed; self-interactions of the adsorbates and formation of stable networks of inter- connected molecules on the AuNP surfaces limit substrate reconstructions, protect the AuNPs from the action of the solvent, and prevent direct interactions of the gold surfaces. The possibility of agglomeration of the functionalized nanoparticles, compared with the sintering of the bare supports in a water solution, is demonstrated through relatively long simulations and fast steered dynamics. The analysis of the trajectories reveals that the AuNPs were well stabilized by the peptides. This prevented particle sintering and kept the particles far apart; however, part of their chains could form interconnections （crosslinks） between neighboring gold vehicles. The excellent agreement of these results with the literature confirm the reliability of the method and its potential application to the modeling of more complex materials relevant to the biomedical sector.
