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Boron doped carbon dots as a multifunctional fluorescent probe for sorbate and vitamin B12
摘要： Boron doped carbon dots (B-CD) were synthesized by a one-step hydrothermal method using phenylboronic acid as the starting material. They have an average size of about 3.3 nm, with excitation/emission wavelength of 247/323 nm and a quantum yield of 12%. The B-CD is shown to be viable fluorescent probe for sorbate (PS) and vitamin B12 (VB12). The fluorescence (FL) of the B-CD is quenched in the presence of PS or VB12 mainly coming from inner filter effect (IFE), but F?rster resonance energy transfer (FRET) from the B-CD (as a donor) to PS/VB12 (as an acceptor) cannot be excluded. The probe enables PS to be detected by fluorometry with a linear response in the 0.20–24 μM concentration range and a 6.1 nM detection limit (at 3σ/slope). For VB12, the data are 0.20–30 μM and 8.0 nM.
关键词： Fluorescent probe,Sorbic acid,Fluorescence quenching ratios,Intra-day precision,Selectivity,Inter-day precision,Quenching mechanism,Real sample analysis
更新于2025-09-23 15:23:52
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Significant improved selectivity of a fluorescent sensor for Al3+ made from a fluorinated rhodamine B Schiff base
摘要： Two rhodamine B-based Schiff bases (RBF, RBC) with different substituent groups (–F and –COOH) have been synthesized. In order to study the sensing properties of two Schiff bases for metal ions, the interaction of Schiff bases with different metal ions was studied over UV–Vis absorption spectra and photofluorescent spectra. The results show that the RBF is a turn-on fluorescent chemosensor for Al3+ ions with being highly selective and sensitive in ethanol. The value of the fluorescence increase factor shows a good linear relationship with the concentration of Al3+ in the range of 1–9 μM with a detection limit of 0.8 μM. Meanwhile, upon addition of Al3+ or Fe3+ ions, the fluorescence intensity of RBC increased significantly (FAl3+/FFe3+ = 0.77). These studies show that, compared with the carboxyl group (–COOH), the introduction of fluorine atoms (–F) to a rhodamine B-based Schiff base can significantly improve selectivity to Al3+.
关键词： Al3+ ion,Fluorine atoms,Fluorescent sensor,Rhodamine B
更新于2025-09-23 15:23:52
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Enhancement strategies of targetability, response and photostability for in vivo bioimaging
摘要： Analyses of the physiology and pathology of active biochemical species in their native contexts are critical for early diagnosis and therapy. Optical imaging has emerged as one of the promising modalities for noninvasive and real-time visualization of important biomolecules or biological events, and it has witnessed major advances in the field of imaging in vitro and in vivo. In this review, we present a survey of common approaches and tactics for enhanced targetability, response rate, and photostability in bioimaging applications. Recently developed and representative examples are illustrated on the cellular and tissue levels.
关键词： targetability,bioimaging,photostability,response rate,fluorescent probe
更新于2025-09-23 15:23:52
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Construction of a Novel Fluorescent Probe for On-site Measuring Hydrogen Sulfide Levels in Food Samples
摘要： Hydrogen sulfide (H2S) has been involved in many foodstuffs and beverages. On-site measuring the H2S level in food samples was beneficial to the concerns about food safety and food quality. Herein, we rationally constructed a novel fluorescent probe to track the H2S levels in various food samples. The optical experiments indicated that the probe displayed highly selective and sensitive response to H2S. In addition, the probe can function well in a wide pH value condition, providing a reliable platform to sense H2S. The practical application demonstrated that the probe was applied for tracking H2S levels in banana, grape, and vinegar for the first time. Importantly, by fabricating test strips, the probe was first served to monitor the released H2S in raw meat without relying on elaborate instrumentation. Thus, the probe could be employed as a simple tool to measure the H2S levels in various food samples, as well as to monitor the fresh-like quality of raw meat under on-site conditions.
关键词： Fluorescent probe,On-site measurement,Hydrogen sulfide,Food sample,Test strip
更新于2025-09-23 15:23:52
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Q-graphene-scaffolded covalent organic frameworks as fluorescent probes and sorbents for the fluorimetry and removal of copper ions
摘要： Metal-free fluorescent covalent organic frameworks (COFs) were synthesized initially with Q-Graphene (QG) scaffolds by the one-step covalent reactions of melamine-aldehyde and phenol-aldehyde poly-condensations using paraformaldehyde. It was discovered that onion-like hollow QG, which consists of multi-layer graphene and different carbon allotropes having a high proportion of folded edges and surface defects, could endow the scaffolded COFs with enhanced green fluorescence and environmental stability. Unexpectedly, they could exhibit the powerful absorption for Cu2+ ions resulting in the specific quenching of fluorescence. A fluorimetric strategy with QG-scaffolded COFs was thereby developed to probe Cu2+ ions separately in blood and wastewater with the linear concentration ranges of 0.0010 - 10.0 μM (limit of detection of 0.50 nM) and 0.0032 - 32.0 μM (limit of detection of 2.4 nM), respectively, promising the potential applications for the field-applicable monitoring of Cu2+ ions in the clinical and environmental analysis fields. In addition, the prepared COFs sorbents were employed to absorb Cu2+ ions in wastewater showing high removal efficiency. More importantly, such an one-pot fabrication route with hollow QG scaffolds may be tailorable extensively for the preparation of a variety of metal-free multifunctional COFs with enhanced fluorescence, water solubility, environmental stability, and metal removal capability.
关键词： Q-Graphene Scaffold；Covalent Organic Frameworks；Fluorescent Analysis；Removal Sorbents；Copper Ions
更新于2025-09-23 15:23:52
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Heteroatom-substituted rhodamine dyes: Structure and spectroscopic properties
摘要： Rhodamine is one class of most popular dyes used in fluorescence imaging due to the outstanding photoproperties including high brightness and photostability. In recent years, replacement the xanthene oxygen with other elements, especially silicon, has attracted great attentions in the development of new rhodamine derivatives. This review summarized the structures and photophysical properties of heteroatom-substituted rhodamines. We hope this review can help to understand the structure-property relationships of rhodamine dyes and then elucidate the way to create derivatives with improved photoproperties.
关键词： Heteroatom,Optical properties,Si-rhodamine,Rhodamine,Fluorescent dyes
更新于2025-09-23 15:23:52
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New Coumarin-benzoxazole derivatives: Synthesis, photophysical and NLO properties
摘要： In this work, a series of novel D-π-A structure coumarin-benzoxazole derivatives have been synthesized. The third-order NLO properties of the coumarin derivatives in DMSO are investigated by Z-scan measurement, and the photophysical properties of the compounds are studied through experimental and theoretical calculation methods. The results showed that the introducing specific functional groups at multiple active sites of coumarin reduced the π-π intermolecular stacking, while the formation of push-pull structure decreased E-gap of entire molecule. The excellent third-order NLO responses based on chromophore 4c with maximum nonlinear absorptive coefficients is 50.64 × 10-13 esu and the largest second-order NLO hyperpolarizability is 7.12 × 10-30 esu. Experimental results have also been confirmed through DFT, TDDFT and ZINDO calculations. Our results indicate that the coumarin fluorescent dyes are promising candidate materials for NLO applications.
关键词： ZINDO calculation,DFT,Fluorescent,Third-order nonlinear,Coumarin derivatives
更新于2025-09-23 15:23:52
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Fluorescent sensor for copper(II) ion based on coumarin derivative and its application in cell imaging
摘要： A novel fluorescent sensor CHT was designed based on the excellent optical properties of coumarin derivatives. It was synthesized by Schiff base reaction connected by 7-(N,N-diethylamino) coumarin-3-aldehyde and 2-hydrazinobenzothiazole. The sensor CHT displayed exhibited a significant fluorescence quenching at 540 nm upon the addition of Cu2+ ions. And the sensor exhibited good sensitivity, fast response time, high selectivity for Cu2+ ions in the presence of other important relevant metal ions. In addition, CHT fluorescent sensor was successfully applied for fluorescent imaging of Cu2+ ions in A549 and MCF-7 cells, demonstrating its potential applications in live cell imaging.
关键词： fluorescent sensor,coumarin,cell imaging,copper(II) ion
更新于2025-09-23 15:23:52
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An inorganic magnetic fluorescent nanoprobe with favorable biocompatibility for dual-modality bioimaging and drug delivery
摘要： In this work, we present the development of a high water soluble biological nanoprobe through the covalent bonding of β-CD onto the surface of iron oxide?gold nanoclusters (Fe3O4@Au@β-CD). Fe3O4@Au@SiO2 NPs were also prepared for comparison. The maximum emission peak of magnetic fluorescent NPs red-shifted by 30 nm and the lifetime was also elongated to 5.21 μs after surface modified with β-CD. The relaxivities and in vitro magnetic resonance imaging ability of the resultant magnetic fluorescent NPs were also studied, indicating that Fe3O4@Au@β-CD NPs have the lowest r2/r1 ratio and could be a potential T2 contrast agent for MR imaging. The MTT assay proved that, Fe3O4@Au@β-CD NPs are of excellent water solubility and biocompatibility. In vitro confocal fluorescence imaging was also performed, manifesting that Fe3O4@Au@β-CD NPs can be selectively uptaken by gastric cancer cells (MGC-803) and exhibit red fluorescence in the cells. The preliminary drug loading and releasing measurements demonstrate that it can also act as targeted drug delivery nanosystem. All these experimental results indicate that, Fe3O4@Au@β-CD NPs hold great application perspective in the diagnosis and therapy of gastric cancer cells as biological nanoprobes.
关键词： Multifunctional,Biocompatibility,Magnetic fluorescent nanocomposites,Drug delivery,Dual-modality imaging
更新于2025-09-23 15:23:52
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Peptide-based ratiometric fluorescent probe for highly selective detection of Cd (II) and its application in bioimaging
摘要： This work reported a new peptide fluorescent probe L including dansyl group (acceptor) and tryptophan (donor) via imitated the binding sites of natural protein. L exhibited exclusively selective ratiometric fluorescence response towards Cd2+ ions over other metal ions based on fluorescent resonance energy transfer (FRET) effects. As designed, L showed exciting sensitivity to Cd2+ ions in aqueous media, and the detection limits are less than 27.5 nM. In addition, the binding pattern of L and Cd2+ was confirmed by fluorescence titration analysis which was found to be 2:1 and further it was confirmed by Job's plot. What' more, L exhibited very low biotoxicity and exciting cell infiltration, and have been successfully used for fluorescence imaging of Cd2+ ions in living HeLa cells.
关键词： Cell imaging,Fluorescent probe,Peptide,Cadmium ion,Ratiometric
更新于2025-09-23 15:23:52