JOURNAL OF RAMAN SPECTROSCOPY
·
2012
·Vol. 44
·期 3
·440-446
·
IF 3.087
Ming-Xia Liu,Bin-Bin Xie,Ming-Juan Li,Yan-Ying Zhao,Ke-Mei Pei,Hui-Gang Wang,Xuming Zheng
The structural dynamics of thioanisole in the S 2 (ππ*) electronic state that has large oscillator strength was studied by using the resonance Raman spectroscopy. The vibrational assignments were done for thioanisole on the basis of the FT-Raman and FT-IR measurements, the density-functional theory computations and the normal mode analysis. The A- and B-band resonance Raman spectra were obtained in cyclohexane, methanol and acetonitrile, in which ten modes in A’ irreducible representations were observed. The structural dynamics were obtained according to the resonance Raman intensity pattern. The vibroinc-coupling between the S 3 (πσ*) electronic state that has no oscillator strength and the S 2 (ππ*) electronic state were revealed. We discuss the correlation between our present structural dynamics and the previous S 2 (ππ*)/S 3 (πσ*) conical intersectional dynamics revealed by resonant-enhanced two-photon ionization and the photofragment excitation spectroscopic study. Copyright © 2012 John Wiley & Sons, Ltd.
研究领域:
化学物理学
·
光谱学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 8
·2101973
·
IF 10.05
Yan Zhao,Shuo-Hui Cao,Jia-Dai Wang,Na Li,Guo-Chun Lin,Yao-Qun Li
Probing light−matter interactions at the nanoscale is essential for elucidation of their fundamentals and construction of novel nano-optical devices. In this work, it is proposed that polarization- and angle-dependent plasmonic synchronous fluorescence spectroscopy could be powerful to resolve UV–vis plasmon mediated molecular couplings, even under vibrational sublevels. Taking studies of polycyclic aromatic hydrocarbons (PAHs, one general class of graphene analogs with emission range of 350–550 nm) as demonstration, a simple but efficient device of PAHs nanolayer (with thickness in tens to hundreds of nanometers) on an Al nano-film is fabricated. By synchronously scanning excitation and emission wavelengths in a high resolution to depict polarization- and angle-dependent spectrographic profiles, the vibrational transitions coupled to the Al plasmons could be identified, while these could not be attained by conventional fluorescence measurement. As a result, the featured molecular vibrational couplings for both surface plasmon- and plasmonic waveguide-mediated PAHs–Al interactions have been successfully observed at room temperature. Even toward crowded and overlapped spectral components containing multiple vibrations, the transitions could be individually distinguished. These efforts will contribute to the further exploitation and construction of efficient light-emitting devices via luminant molecules on a metal surface.
研究领域:
光学
·
纳米科技
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2022
·
IF 6.888
Guoliang Xu,Ruiling Dong,Dayong Gu,Huili Tian,Lei Xiong,Zhixun Wang,Wei Wang,Yan Shao,Wenjie Li,Guangyuan Li,Xue Zheng,Yang Yu,Ye Feng,Yuming Dong,Guohua Zhong,Baoping Zhang,Weimin Li,Lei Wei,Chunlei Yang,Ming Chen
Defect engineering with the active control of defect states brings remarkable enhancement on surface-enhanced Raman scattering (SERS) by magnifying semiconductor–molecule interaction. Such light-trapping architectures can increase the light path length, which promotes photon–analytes interactions and further improves the SERS sensitivity. However, by far the reported semiconductor SERS-active substrates based on these strategies are often nonuniform and commonly in the form of isolated laminates or random clusters, which limit their reliability and stability for practical applications. Herein, we develop self-grown single-crystalline “V-shape” SnSe2-x (SnSe1.5, SnSe1.75, SnSe2) nanoflake arrays (SnSe2-x NFAs) with controlled selenium vacancies over large-area (10 cm × 10 cm) for ultrahigh-sensitivity SERS. First-principles density functional theory (DFT) is used to calculate the band gap and the electronic density of states (DOS). Based on the Herzberg–Teller theory regarding the vibronic coupling, the results of theoretical calculation reveal that the downshift of band edge and high DOS of SnSe1.75 can effectively enhance the vibronic coupling within the SnSe1.75–R6G system, which in turn enhances the photoinduced charge transfer resonance and contributes to the SERS activity with a remarkable enhancement factor of 1.68 × 107. Furthermore, we propose and demonstrate ultrasensitive (10–15 M for R6G), uniform, and reliable SERS substrates by forming SnSe1.75 NFAs/Au heterostructures via a facile Au evaporation process. We attribute the superior performance of our SnSe1.75 NFAs/Au heterostructures to the following reasons: (1) selenium vacancies and (2) synergistic effect of the near and far fields. In addition, we successfully build a detection platform to achieve rapid (∼15 min for the whole process), antibody-free, in situ, and reliable early malaria detection (100% detection rate for 10 samples with 160 points) in whole blood, and molecular hemozoin (<100/mL) can be detected. Our approach not only provides an efficient technique to obtain large-area, uniform, and reliable SERS-active substrates but also offers a substantial impact on addressing practical issues in many application scenarios such as the detection of insect-borne infectious diseases.
研究领域:
分析化学
·
纳米技术
·
材料科学
·
生物医学工程
·
光学
·
疾病检测
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry B
·
2024
·
IF 6.1
Lingfeng Wang,Ying Qian
In this paper, the heavy-atom-free BODIPY dendrimer TM4-BDP was synthesized for the near-infrared photodynamic therapy, which was composed of the triphenylamine-BODIPY dimer and four 1-(2-morpholinoethyl)-1H-indole-3-ethenyl groups. The TM4-BDP could achieve the near-infrared photodynamic therapy through two different photosensitive pathway, which include the one-photon excitation at 660 nm and two-photon excitation at 1000 nm. In the one-photon excitation pathway, the TM4-BDP could generate singlet oxygen and superoxide radical under 660 nm illumination. In addition, the one-photon PDT experiment in human nasopharyngeal carcinoma (CNE-2) cells also indicated that the TM4-BDP could specific accumulate in lysosomes and shown great cell phototoxicity with the IC50 at 22.1μM. In the two-photon excitation pathway, the two-photon absorption cross section at 1030 nm of TM4-BDP was determined as 383 GM, which make it could generate the reactive oxygen species (ROS) under 1000 nm femtosecond laser excitation. Moreover, the two-photon PDT experiment in zebrafish also indicated the TM4-BDP could be used for the two-photon fluorescence imaging and the two-photon induced ROS generation in biological environment. Besides that, in the ROS generation mechanism aspect, the TM4-BDP employ the novel spin-vibronic coupling intersystem crossing (SV-ISC) process for the mechanism of ROS generation and the femtosecond transient absorption spectra indicated that this novel SV-ISC mechanism was closely related with its’ lifetime of charge transfer state. These above experiments of TM4-BDP demonstrate that the dendrimer design was an effective strategy for constructing heavy-atom-free NIR BODIPY photosensitizers and lay the foundation for the two-photon photodynamic therapy in the future clinical trails.
研究领域:
光动力疗法
·
纳米技术
·
生物医学工程
·
材料科学
·
光学
·
药物化学
·
分子生物学
·
细胞生物学
·
斑马鱼研究
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）