In broadband coherent anti-Stokes Raman scattering （CARS） spectroscopy with supercontinuum （SC）, the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of variou...In broadband coherent anti-Stokes Raman scattering （CARS） spectroscopy with supercontinuum （SC）, the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science.展开更多
Plasmonicnanoparticles(PNPs)with stable nanogaps are important to achieve strong,uniform and quantitative gap-enhanced Raman scattering(GERS)signals.Chiral PNPs with plasmonic circular dichroism(PCD)responses have bee...Plasmonicnanoparticles(PNPs)with stable nanogaps are important to achieve strong,uniform and quantitative gap-enhanced Raman scattering(GERS)signals.Chiral PNPs with plasmonic circular dichroism(PCD)responses have been discovered to be suitable for applications in enantiomeric recognition,cancer therapy and activation of immune system.Herein,two-thiolsmodulated growth was demonstrated to result in the acquisition of PNPs with synergistically enhanced GERS and PCD signals.4-Aminothiophenol(4-ATP)and cysteine(Cys)played the role of Raman reporter and chiral stimulus,respectively.At a fixed 4-ATP concentration,the GERS signal of PNPs was significantly enhanced with the increase of the concentration of Cys.Simultaneously,at a fixed concentration of Cys,an increase in PCD response was observed by elevating the concentration of 4-ATP.Both aforementioned molecules acted as morphology controllers,leading to the formation of helical shell.It is suggested that the giant GERS and PCD response were contributed by the‘‘hot spots''within the PNPs and more perfect helical shells.Our research pointed out a novel synthetic guideline to obtain PNPs with multiple functionalities by incorporating multi-ligands into the growth stages.展开更多
We review recent our results in the fundamental study of surface-enhanced Raman scattering （SERS） with emphasis on experiments that attempted to identify the enhancement and blinking mechanism using single Ag nanopa...We review recent our results in the fundamental study of surface-enhanced Raman scattering （SERS） with emphasis on experiments that attempted to identify the enhancement and blinking mechanism using single Ag nanoparticle dimers attached to dye molecules. These results are quantitatively discussed in the framework of electromagnetic mechanism. We also review recent our results in basic SERS applications for biological sensing regarding detections of cell surface molecules and distinction of disease marker molecules under single cell and single molecule level.展开更多
The single-molecule surface-enhanced Raman scattering （smSERS） has been extensively studied after the initial observation in 1997, yet there still exist unsettled issues in the fundamental mechanism of smSERS. In th...The single-molecule surface-enhanced Raman scattering （smSERS） has been extensively studied after the initial observation in 1997, yet there still exist unsettled issues in the fundamental mechanism of smSERS. In this review, we survey some of the recent breakthroughs in the mechanism of smSERS and its application.展开更多
The reaction dynamics of the fluorine atom with vibrationally excited D2(v=1, v=0) was investigated using the crossed beam method. The scheme of stimulated Raman pumping was employed for preparation of vibrationally e...The reaction dynamics of the fluorine atom with vibrationally excited D2(v=1, v=0) was investigated using the crossed beam method. The scheme of stimulated Raman pumping was employed for preparation of vibrationally excited D2 molecules. Contribution from the reaction of spin-orbit excited F*(2P1/2) with vibrationally excited D2 was not found. Reaction of spin-orbit ground F(2P3/2) with vibrationally excited D2 was measured and DF products populated in v'=2, 3, 4, 5 were observed. Compared with the vibrationally ground reaction, DF products from the vibrationally excited reaction of F(2P3/2)+D2(v=1, j=0) are rotationally “hotter”. Differential cross sections at four collision energies, ranging from 0.32 kcal/mol to 2.62 kcal/mol, were obtained. Backward scattering dominates for DF products in all vibrational levels at the lowest collision energy of 0.32 kcal/mol. As the collision energy increases, angular distribution of DF products gradually shifts from backward to sideway. The collision-energy dependence of differential cross section of DF(v’=5) at forward direction was also measured. Forward-scattered signal of DF(v'=5) appears at the collision energy of 1.0 kcal/mol, and becomes dominated at 2.62 kcal/mol.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.60627003)the Foundation for Creative Team in Institution of Higher Education of Guangdong Province,China(Grant No.06CXTD009)
文摘In broadband coherent anti-Stokes Raman scattering （CARS） spectroscopy with supercontinuum （SC）, the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science.
基金financially supported by the National Natural Science Foundation of China (Nos.22072032 and21902148)the Key Science and Technology Program of Henan Province (No.192102210004)+2 种基金the Research Initiated Project of Chengdu University (No.2081921109)Chengdu University Graduate Talent Training Quality and Teaching Reform Project (No.cdjgy2022034)Chengdu University Talent Training Quality and Teaching Reform Project (No.cdjgb2022103)。
文摘Plasmonicnanoparticles(PNPs)with stable nanogaps are important to achieve strong,uniform and quantitative gap-enhanced Raman scattering(GERS)signals.Chiral PNPs with plasmonic circular dichroism(PCD)responses have been discovered to be suitable for applications in enantiomeric recognition,cancer therapy and activation of immune system.Herein,two-thiolsmodulated growth was demonstrated to result in the acquisition of PNPs with synergistically enhanced GERS and PCD signals.4-Aminothiophenol(4-ATP)and cysteine(Cys)played the role of Raman reporter and chiral stimulus,respectively.At a fixed 4-ATP concentration,the GERS signal of PNPs was significantly enhanced with the increase of the concentration of Cys.Simultaneously,at a fixed concentration of Cys,an increase in PCD response was observed by elevating the concentration of 4-ATP.Both aforementioned molecules acted as morphology controllers,leading to the formation of helical shell.It is suggested that the giant GERS and PCD response were contributed by the‘‘hot spots''within the PNPs and more perfect helical shells.Our research pointed out a novel synthetic guideline to obtain PNPs with multiple functionalities by incorporating multi-ligands into the growth stages.
文摘We review recent our results in the fundamental study of surface-enhanced Raman scattering （SERS） with emphasis on experiments that attempted to identify the enhancement and blinking mechanism using single Ag nanoparticle dimers attached to dye molecules. These results are quantitatively discussed in the framework of electromagnetic mechanism. We also review recent our results in basic SERS applications for biological sensing regarding detections of cell surface molecules and distinction of disease marker molecules under single cell and single molecule level.
文摘The single-molecule surface-enhanced Raman scattering （smSERS） has been extensively studied after the initial observation in 1997, yet there still exist unsettled issues in the fundamental mechanism of smSERS. In this review, we survey some of the recent breakthroughs in the mechanism of smSERS and its application.
基金supported by the Ministry of Science and Technology (No.2017YFF0104500)the Chinese Academy of Sciences (No.XDB17000000)the National Natural Science Foundation of China (No.21573226, No.21822305)
文摘The reaction dynamics of the fluorine atom with vibrationally excited D2(v=1, v=0) was investigated using the crossed beam method. The scheme of stimulated Raman pumping was employed for preparation of vibrationally excited D2 molecules. Contribution from the reaction of spin-orbit excited F*(2P1/2) with vibrationally excited D2 was not found. Reaction of spin-orbit ground F(2P3/2) with vibrationally excited D2 was measured and DF products populated in v'=2, 3, 4, 5 were observed. Compared with the vibrationally ground reaction, DF products from the vibrationally excited reaction of F(2P3/2)+D2(v=1, j=0) are rotationally “hotter”. Differential cross sections at four collision energies, ranging from 0.32 kcal/mol to 2.62 kcal/mol, were obtained. Backward scattering dominates for DF products in all vibrational levels at the lowest collision energy of 0.32 kcal/mol. As the collision energy increases, angular distribution of DF products gradually shifts from backward to sideway. The collision-energy dependence of differential cross section of DF(v’=5) at forward direction was also measured. Forward-scattered signal of DF(v'=5) appears at the collision energy of 1.0 kcal/mol, and becomes dominated at 2.62 kcal/mol.
基金The National Natural Science Foundation of China(Nos.61275153,61320106014,and 11404177)the Natural Science Foundation of Zhejiang(No.LY12A04002)the International Collaboration Program of the Natural Science Foundation of Ningbo(Nos.2010D10018and 2012A610107)
