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- 摘要
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- 实验方案
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A novel 1,8-naphthalimide as highly selective naked-eye and ratiometric fluorescent sensor for detection of Hg2+ ions
摘要： A novel colorimetric and ratiometric fluorescent chemosensor, 2-(2-mercaptophenyl)-1H-benzo[de]isoquinoline-1,3-(2H)-dione (L3) is reported for Hg2+ ions. The selective binding of Hg2+ to L3 afforded new absorbance and fluorescence peaks at 438 nm and 480 nm, in addition to the existing bands of L3 at 332 nm and 376 nm. It also showed apparent colour change from colourless to yellowish green and weak fluorescent to bright yellowish green strong fluorescent due to selective binding of Hg2+ ion. The sensor forms a 1:1 stoichiometry with high binding constants (3.89 × 10^4 mol^-1 L) and limit of detection 1.74 × 10^-8 M with high selectivity and sensitivity towards Hg2+ in the presence of other interfering metal ions. More importantly, it has good practicability in environmental water sample. The outcome of photo-physical experiment has also been in good accordance with the time-resolved fluorescence life decays and the density functional theory (DFT) estimations. Moreover, the L3-Hg2+ solution displayed high colorimetric and fluorimetric reversibility via the addition of KI. This reversibility in fluorescence showed potential applicability of chemosensor L3 as 'on–off–on' naked eye sensor.
关键词： Molecular logic gate,Red-shift,DFT,Off–on–off Hg2+ chemosensor,Naked eye detection,Ratiometric fluorescence
更新于2025-09-19 17:15:36
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A colorimetric and fluorescent chemosensor for Hg <sup>2+</sup> based on a photochromic diarylethene with a quinoline unit
摘要： A new colorimetric and fluorescent 'on–off' chemosensor, 1O, based on a photochromic diarylethene with a quinoline unit was designed and synthesized. The chemosensor 1O demonstrated selective and sensitive detection of Hg2+ ions in the presence of other competitive metal ions in acetonitrile. The stoichiometric ratio of the sensor 1O for Hg2+ was determined to be 1 : 1, and the limit of detection of the probe 1O was calculated to be 56.3 nM for Hg2+. In addition, a molecular logic circuit with four inputs and one output was successfully constructed with UV/vis light and metal-responsive behavior. ESI-MS spectroscopy, Job's plot analysis, and 1H NMR titration experiments confirm the binding behavior between 1O and Hg2+.
关键词： quinoline,logic circuit,fluorescent,Hg2+,colorimetric,diarylethene,chemosensor,photochromic
更新于2025-09-19 17:15:36
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Formation of emissive nanoparticles from tetraphenylethylene-containing boronate macrocycles: preparation, characterization and functionalization
摘要： Formation of emissive nanoparticles from tetraphenylethylene-containing boronate macrocycles: preparation, characterization and functionalization. [2+2] Macrocycles composed of two tetraphenylethylenes (TPEs) and two linkers, namely 1a (R = H) and 1b (R = NO2), were prepared in a facile manner through the one-pot dehydration of gem-di(boronic acid)-appended TPEs 2a (R = H) and 2b (R = NO2) with di(trimethylolpropane) 3 in MeOH. Considering that use of THF instead of MeOH as the reaction solvent gave a mixture of boronate esters, hydrophobicity-induced non-covalent interactions involving mono(boronate ester) intermediates produced by the dehydration of 2 and 3, may be responsible for the selective cyclization in MeOH. We found that these boronate macrocycles formed emissive nanoparticles of 1a (λem = 483 nm, λex = 365 nm, ΦF = 31%) and 1b (λem = 539 nm, λex = 365 nm, ΦF = 11%) in H2O, with average diameters of 312 ± 44.6 nm and 146 ± 25.5 nm, respectively. The dynamic features of these particles endow them with reversible thermoresponsive properties; indeed, emissiveness responded linearly to temperature over the tested range. The hysteresis-free temperature sensitivity (S) of the 1a-based nanoparticles was determined to be 0.75% K?1 in H2O. Such behavior was rationalized by dynamic light scattering (DLS) experiments, which facilitated the detection of particle-size changes in response to temperature. As a control, bis(pinacolboryl)-appended TPE 6, which does not form nanoparticles in H2O, was poorly responsive to changes in temperature. Furthermore, effective emission quenching was observed upon addition of 2,6-dichloro-4-nitroaniline (DCN), a toxic pesticide, at a detection limit of 2.00 ppm in H2O/MeOH (3 : 2 v/v). Although DCN-induced quenching is ascribable to the nature of the TPE units, the self-assembled nanoparticle morphologies were altered upon addition of DCN, as determined by DLS and field-emission scanning electron microscopy (FE-SEM), and appeared to involve an Ostwald ripening process.
关键词： boronate macrocycles,tetraphenylethylene,thermoresponsive,nanoparticles,aggregation-induced emission,chemosensor
更新于2025-09-19 17:15:36
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Bismuth Ions Selective Fluorescent Chemosensor Based on Rhodamine-B
摘要： A new rhodamine-based compound (L1) has been synthesized and applied as an "off-on" chemosensor for Bi3+. The complexation behaviour of chemosensor with different metal ions including Bi3+ ions in EtOH/H2O (4:1, v/v) was studied on UV-visible absorption spectra and fluorescent spectra. Results showed that the chemosensor (L1) is highly selective for Bi3+ over other cations such as Hg2+, Fe2+, Mn2+ and Ca2+. This selectivity can be attributed to the photoinduced electron transfer mechanism (PET) of the sensor in the presence of Bi3+. The complex solution (L1-Bi3+) exhibited reversibility with EDTA.
关键词： Fluorescent chemosensor,Rhodamine-B,Bismuth ions.
更新于2025-09-19 17:15:36
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Selective Ultrasensitive Optical Fiber Nanosensors Based on Plasmon Resonance Energy Transfer
摘要： The facet of optical fibers coated with nanostructures enable the development of ultraminiature and sensitive (bio)chemical sensors. The reported sensors until now lack of specificity and the fabrication methods offer poor reproducibility. Here, we demonstrate that by transforming the facet of conventional multimode optical fibers onto plasmon resonance energy transfer (PRET) antenna surfaces the specificity issues may be overcome. To do so, a low cost chemical approach was developed to immobilize gold nanoparticles on the optical fiber facet in a reproducible and controlled manner. Our nanosensors are highly selective as PRET is a nanospectroscopic effect that only occurs when the resonant wavelength of the nanoparticles matches that of the target parameter. As an example, we demonstrate the selective detection of picomolar concentrations of copper ions in water. Our sensor is 1,000 times more sensitive than state of the art technologies. An additional advantage of our nanosensors is their simple interrogation; it comprises of a low-power light emitting diode, a multimode optical fiber coupler, and a miniature spectrometer. We believe that the PRET-based fiber optic platform reported here may pave the way of the development of a new generation of ultra-miniature, portable, and hypersensitive and selective (bio)chemical sensors.
关键词： plasmonics,chemosensor,nanoparticles,optical fiber,metal ion
更新于2025-09-19 17:13:59
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CdS quantum dots embedded in PVP: Inorganic phosphate ion sensing in real sample and its antimicrobial activity
摘要： Polyvinyl-pyrrolidone capped spherical cadmium sulphide quantum dots (CdS-PVP QDs), 2–6 nm in size, were developed as a selective turn-on fluorescence nanosensor for monohydrogen phosphate ion (HPO4 2?) in aqueous medium. Fluorescence intensity of CdS-PVP QDs significantly increased with addition of HPO4 2? ions, whereas the other common inorganic ions had very little effect on the fluorescence intensity. The proposed sensor may be efficiently used for the detection of HPO4 2? ions at a low level of concentration up to 213 nM in real urine sample. Cell imaging study indicates that the CdS-PVP QDs are cell permeable and can detect the intracellular distribution of HPO4 2? ions under fluorescence microscope. The CdS-PVP QDs showed considerable activity against Staphylococcus aureus also.
关键词： Chemosensor,CdS,Antimicrobial activity,Cell image,Quantum dots,Phosphate ion sensing
更新于2025-09-19 17:13:59
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Synthesis and application of a surface ionic imprinting polymer on silica-coated Mn-doped ZnS quantum dots as a chemosensor for the selective quantification of inorganic arsenic in fish
摘要： A novel room temperature phosphorescence chemosensor probe has been successfully developed and applied to the selective detection and quantification of inorganic arsenic (As(III) plus As(V)) in fish samples. The prepared material (IIP@ZnS:Mn QDs) was based on Mn-doped ZnS quantum dots coated with (3-aminopropyl) triethoxysilane and an As(III) ionic imprinted polymer. The novel use of vinyl imidazole as a complexing reagent when synthesizing the ionic imprinted polymer guarantees that both inorganic arsenic species (As(III) and As(V)) can interact with the recognition cavities in the ionic imprinted polymer. After characterization, several studies were performed to enhance the interaction between the targets (As(III) and As(V) ions) and the IIP@ZnS:Mn QDs nanoparticles. The optimization and validation process showed that the composite material offers high selectivity (high imprinting factor) for inorganic arsenic species. The limit of quantification for total inorganic As was 29.6 μg kg?1, value lower than the EU/EC regulation limits proposed for other foodstuffs than fish, such as rice. The proposed method is therefore simple, requires short analysis times and offers good sensitivity, precision (inter-day relative standard deviations lower than 10%), and quantitative analytical recoveries. The method has been successfully applied to assess total inorganic arsenic in several fishery products, showing good agreement with the total inorganic arsenic concentration (As(III) plus As(V)) found after applying other advanced and expensive methods such those based on high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry.
关键词： Ionic imprinted polymer,Silica-coated Mn-doped ZnS quantum dots,Fish,Room temperature phosphorescence,Chemosensor probe,Inorganic arsenic
更新于2025-09-16 10:30:52
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Pyridine-hydrazone-controlled cyanide detection in aqueous media and solid-state: tuning the excited-state intramolecular proton transfer (ESIPT) fluorescence modulated by intramolecular NH?Br hydrogen bonding
摘要： A new efficient pyridine-hydrazone-substituted naphthalimide receptor 4a-E has been synthesized as a selective colorimetric and fluorescent chemosensor for cyanide sensing in aqueous environments through a unique excited-state intramolecular proton transfer (ESIPT) mechanism. The addition of a Br group to the fluorophore skeleton at the ortho-position of hydrazone generates reference compounds (4b-E and 4c-Z). Interestingly, the potential intramolecular NH?Br hydrogen bonding might compete with the anion-induced intermolecular NH?A? hydrogen bonding, resulting in dramatic ESIPT suppression. The high emission of probe 4a-E and other control probes in solid-state is also investigated. Moreover, probe 4a-E preloaded on test papers, upon cyanide treatment, shows obvious changes in color which demonstrates that 4a-E is a writable platform. More importantly, it exhibits great potential application for the detection of cyanide in food materials and excellent performance in real-world water samples.
关键词： ESIPT,colorimetric,pyridine-hydrazone,fluorescent chemosensor,cyanide sensing
更新于2025-09-12 10:27:22
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Laser systems for time-resolved experiments at the Pohang Accelerator Laboratory X-ray Free-Electron Laser beamlines
摘要： Investigation of highly sensitive and selective fluorescent materials for transition metal ions has attracted significant interest because of their important roles in biological and environmental importances. Because the second most plentiful transition metal ion in human body, Zn2+ plays various critical roles in biological functions including neuronal signal transmission, enzymatic regulations, influencing DNA synthesis, and numerous cellular functions. In this respect, sensitive and noninvasive technique to detect free zinc ions, which are spectroscopically silent due to its 3d10 electron configurations, is one of the important research areas. However, most of the reported wavelengths of the chemosensors and their emissions are still lies in blue or green region, and only a few molecules showed red or orange emissions, which are better wavelengths in cellular bioimaging.
关键词： Zn2+ ion,Specific binding,Excited-state intramolecular proton transfer,Thiazole,Chemosensor
更新于2025-09-11 14:15:04
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Carbon Dots as Cosensitizers in Dye-Sensitized Solar Cells and Fluorescence Chemosensors for 2,4,6-Trinitrophenol Detection
摘要： Carbon dots (CDs) are a unique class of fluorescent nanomaterials, whose emissions can be tuned by manipulating the reaction conditions of their formation. Herein, we report a facile solvothermal route for producing CDs with tunable properties by employing N,N-dimethylformamide (DMF) as the solvent medium. Using completely green carbon sources, two types of CDs are synthesized: citric acid produces green emitting CDs (G-CDs) while gallic acid produces blue emitting CDs (B-CDs). The optical analysis of the G-CDs suggests their application as co-sensitizers along with N719 dye in dye sensitized solar cells (DSSCs). Following this, the effect of G-CDs in DSSCs was studied and a photo-conversion efficiency of 6.9% was extracted from the device. Meanwhile, the B-CDs produced from gallic acid are hydrophobic in nature and their blue colored emission is quenched in the vicinity of TNP in less than 1 min with a limit of detection of 0.75 μM.
关键词： Carbon dots,Fluorescence chemosensor,Dye sensitized solar cells,2,4,6-Trinitrophenol detection
更新于2025-09-11 14:15:04