Red/near-infrared (NIR) emissive carbon nanodots (CNDs) with photoluminescence (PL) quantum yield (QY) of 57% are prepared via an in situ solvent-free carbonization strategy for the first time. 1-Photon and 2-photon cellular imaging is demonstrated by using the CNDs as red/NIR fluorescence agent due to the high PL QY and low biotoxicity. Further study shows that the red/NIR CNDs exhibit multiphoton excited (MPE) upconversion fluorescence under excitation of 800-2000 nm, which involves three NIR windows (NIR-I, 650-950 nm; NIR-II, 1100-1350; NIR-III, 1600-1870 nm). 2-Photon, 3-photon, and 4-photon excited fluorescence of the CNDs under excitation of different wavelengths is achieved. This study develops an in situ solvent-free carbonization method for efficient red/NIR emissive CNDs with MPE upconversion fluorescence, which may push forward the application of the CNDs in bioimaging.
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http://dx.doi.org/10.1002/advs.201900766 | DOI Listing |
Research has shown that the expression level of microRNA-155 (miRNA-155) is positively correlated with clinical stage and depth of invasion in patients with cervical cancer and cervical intraepithelial neoplasia and tends to be highly expressed. Therefore, it is very important to develop sensitive miRNA-155 analysis methods for the early diagnosis, treatment, and prognostic evaluation of cervical cancer. In this study, a near-infrared light-driven fluorescent biosensor based on the metal-enhanced fluorescence effect of polydopamine-coated upconversion nanoparticle (UP/Au) and two toehold-mediated strand displacement (TMSD) steps was constructed for the detection of miRNA-155.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States.
Donor-acceptor dyads are promising materials for improving triplet-sensitized photon upconversion due to faster intramolecular energy transfer (ET), which unfortunately competes with charge transfer (CT) dynamics. To circumvent the issue associated with CT, we propose a novel purely organic donor-acceptor dyad, where the CT character is confined within the donor moiety. In this work, we report the synthesis and characterization of a stable organic radical donor-triplet acceptor dyad () consisting of the acceptor perylene () linked to the donor (4--carbazolyl-2,6-dichlorophenyl)-bis(2,4,6-trichlorophenyl)methyl radical ().
View Article and Find Full Text PDFAnal Chem
December 2024
Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
Methylglyoxal is considered a key indicator in evaluating wine flavor and quality, as well as an important marker for diabetic pathological syndromes. Rapid and accurate quantitative detection of methylglyoxal is essential in scenarios of wine production standards and human health monitoring. Herein, we report a visual method for detecting methylglyoxal via an NIR-excitable reversible ratiometric fluorescent hydrogel sensor, where NIR-excited upconversion nanoparticles serve as energy donors and eosin B acts as the energy acceptor, together forming an integrated ratiometric nanophotonic probe that ensures the accuracy of detection without being affected by various background fluorescence interference in different scenarios.
View Article and Find Full Text PDFSensors (Basel)
December 2024
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Food safety is of great concern, and food-borne bacterial infections and diseases are a major crisis for health. Therefore, it is necessary to develop rapid detection techniques for the prevention and recognition of food safety hazards caused by food-borne pathogens. In recent years, the fluorescence assay has become a widely utilized detection method due to its good signal amplification effect, high detection sensitivity, high stability, and short detection time.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen 518033, China.
The performance optimization of photoluminescent (PL) materials is a hot topic in the field of applied materials research. There are many different crystal defects in photoluminescent materials, which can have a significant impact on their optical properties. The luminescent properties and chemical stability of materials can be effectively improved by adjusting lattice defects in crystals.
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