We report, to our best knowledge, the first observation of enhanced third upconversion Raman overtone of water in the ultraviolet region 240-380 nm by Rhodamine 6G (R6G) under intense excitation of a 532 nm laser. Its spectral peak is mostly around 288 nm. This ultraviolet spectrum has also been obtained for purified water on the Raman spectrometer LRS-3 and fluorescence spectrometer RF-5301PC, which have photomultiplier tubes. The spectral profile is approximately a triangle in most cases. Moreover, an intense and broad background is also observed to appear in the spectrum. Additionally, the conventional visible luminescence spectrum of R6G is discovered to coexist with the ultraviolet one. In comparison, the visible spectrum is much more intense.
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http://dx.doi.org/10.1364/OL.44.004741 | DOI Listing |
Nano Lett
December 2024
Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China.
Aggregation-induced emission (AIE) photosensitizers are promising for photodynamic therapy, yet their short excitation wavelengths present a limitation. In this study, we develop a series of organic photosensitizers with dual modulation capabilities based on excited-state intramolecular proton transfer (ESIPT) and AIE. Notably, we synthesize near-infrared (NIR)-excited photosensitive nanoparticles through a coassembly strategy utilizing upconversion nanoparticles (UCNPs) and amphiphilic polymers.
View Article and Find Full Text PDFNanophotonics
July 2024
Institute of Electro-Optical Engineering, National Taiwan Normal University, Taipei 11677, Taiwan.
We develop a new all-dielectric metasurface for designing high quality-factor (-factor) quasi-bound states in the continuum (quasi-BICs) using asymmetry kite-shaped nanopillar arrays. The -factors of quasi-BICs follow the quadratic dependence on the geometry asymmetry, and meanwhile their resonant spectral profiles can be readily tuned between Fano and Lorentzian lineshapes through the interplay with the broadband magnetic dipole mode. The third-harmonic signals of quasi-BIC modes exhibit a gain from 43.
View Article and Find Full Text PDFSmall
November 2024
Innovation and Research Institute of Hebei University of Technology in Shijiazhuang, School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Xiping Road, Tianjin, 300130, P. R. China.
Anal Bioanal Chem
January 2025
Pharmacy College, Henan University of Chinese Medicine, Zhengzhou, 450046, PR China.
Epidermal growth factor receptor (EGFR) mutations play a key role in the development of a variety of cancers. Rapid detection and screening of EGFR mutation types in patients are of great significance for early treatment of patients. In this study, a highly sensitive fluorescent biosensing system based on lanthanide ion-doped multi-type upconversion nanoparticles (UCNPs) combined with polymerization reaction signal amplification was designed and constructed for the simultaneous detection of L858R and 19Del mutations.
View Article and Find Full Text PDFMid-infrared (MIR) microcombs exhibit remarkable advantages for trace molecule detection, facilitating fast and precise spectral analysis. However, due to limitations in tunability and size of available MIR pump sources, it is difficult to achieve compact MIR mode-locked microcombs using traditional methods. Here, we propose the turnkey generation of MIR soliton and near-infrared second-harmonic microcombs in a single microresonator.
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