- 标题
- 摘要
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- 实验方案
- 产品
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Highly Sensitive and Selective Fluorescent Sensor based on a Multi-Responsive Ultrastable Amino-Functionalized Zn(II)-MOF for Hazardous Chemicals
摘要： A microscale amino-functionalized Zn(II)-MOF, namely [Zn(NH2-bdc)(4,4’-bpy)] (1) (NH2-H2bdc = 2-amino-1,4-benzenedicarboxylic acid and 4,4’-bpy = 4,4’-bipyridine), has been successfully synthesized, structurally characterized and further utilized as multi-responsive fluorescent sensor for highly sensitive and selective detection of Cr(VI) and 2,4,6-trinitrophenol (TNP). Compound 1 features non-porous 5-fold interpenetrated 3D framework with the Lewis basic sites including the uncoordinated amino and carboxylate groups on the framework for anchoring and recognizing the guest. 1 exhibits not only excellent water and thermal stability but also tolerance to acidic and basic media over an extensive pH range of 2-12. This ultrastable material can sensitively and selectively detect Cr2O7 2- and CrO4 2- in water based on the luminescent quenching with relatively low limits of detection (2.21 μM for CrO4 2- and 1.30 μM for Cr2O7 2-). Moreover, the unprecedented solvent-dependent luminescent response of 1 as a fluorescent probe for high-efficiency TNP detection was observed. Significantly, 1 not only displays high sensitive fluorescent enhancement upon TNP binding in ethanol but also exhibits fluorescent quenching toward TNP in water with very low limits of detection of 4.47 nM and 0.32 μM in ethanol and water, respectively. This work reports the first example of the utilization of MOF as a sensor for the detection of TNP based on dual responsive luminescence. Importantly, 1 can be simply and rapidly regenerated, displaying excellent recyclability after the sensing experiments.
关键词： Multi-responsive fluorescent sensors,Fluorescent quenching,Metal-organic framework,2,4,6-trinitrophenol,Fluorescent enhancement,Cr(VI)
更新于2025-11-19 16:46:39
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Fluorescent Sensors Based on a Novel Functional Design: Combination of an Environment-sensitive Fluorophore with Polymeric and Self-assembled Architectures
摘要： The fluorescence properties, e.g., fluorescence intensity, of fluorescent sensors can change due to covalent derivatization or noncovalent complexation with a target chemical species (i.e., molecules and ions) or by variations in circumstantial physical parameters (e.g., temperature and viscosity). The internal charge transfer (ICT) character and photoinduced electron transfer (PET) efficiency can be used to tune the fluorescence switching mechanism, facilitating the development of new fluorescent sensors. In addition, the utilization of an environment─ sensitive (i.e., polarity─ and hydrogen bonding─ sensitive) fluorophore in stimulus─ responsive macromolecules to design novel fluorescent sensors has been proposed. Based on this concept, highly sensitive fluorescent polymeric thermometers and (extremely sensitive) digital fluorescent pH sensors have been developed. These thermometers are being used to measure the temperature of live cells in biological and medical studies. This concept has also allowed nanoscale proton mapping near membranes, which exemplifies the downsizing of targets for fluorescent sensing from a micrometer─ scale to a nanometer─ scale.
关键词： digital fluorescent pH sensors,polymeric thermometers,nanoscale proton mapping,fluorescent sensors,environment─ sensitive fluorophore
更新于2025-09-23 15:19:57
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Method of the Year 2018: Imaging in freely behaving animals
摘要： Neuronal imaging in unrestrained animals has expanded the range of behaviors amenable to circuit-level studies in several model organisms. Advances in imaging technology and in fluorescent sensors have allowed detailed analyses of the neuronal activity underlying a variety of behaviors in animals as diverse as rats, mice, fish, flies and worms. Restraining animals gives experimenters exquisite control over the sensory environment of their subjects, which can be advantageous for studies of visually guided or olfactory-guided behaviors, for example. However, restrained animals are limited in their ability to exhibit more complex behaviors, particularly social behaviors. Technological developments in recent years have made it possible to image neuronal activity in freely behaving animals. For its potential to allow scientists to study the neuronal basis of naturalistic behaviors at the cell, circuit and whole-brain levels, we have chosen imaging in freely behaving animals as Method of the Year 2018.
关键词： naturalistic behaviors,freely behaving animals,circuit-level studies,fluorescent sensors,neuronal imaging
更新于2025-09-23 15:19:57
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Ultrafast, sensitive and visual sensing of copper ions by a dual-fluorescent film based on quantum dots
摘要： The use of fluorescent sensors is one of the most promising approaches for meeting the growing demand for a sensitive, convenient and cost-effective detection method of metal ions. However, visual sensing based on fluorescent materials remains a challenge due to the hard-to-see changes in fluorescence intensity, long response time and poor stability. Here, a simple and effective film sensor was developed for the visual detection of Cu2+ using quantum dots (QDs) modified by polyethylenimine (PEI) and poly(vinylidene fluoride) (PVDF) by electrospinning and dip-coating methods. QDsr-PEI on the surface of nanofibers could be used as a responsive red fluorescence signal, while the QDsg dispersed in the nanofibers were used as a green background signal. Due to the high Cu2+ binding capacity of PEI and the contrast-color sensitivity of the two kinds of QDs, it realized an obvious fluorescence change from red to green toward Cu2+ in the liquid phase with a short response time of 30 s and a low detection limit of 2 mM by observation. Furthermore, the film exhibited excellent fluorescence stability to a high temperature and UV light, which is beneficial for satisfying much more possible applications. These results demonstrate that the dual fluorescent film sensor has a great potential for the real-time and visual detection of Cu2+.
关键词： dip-coating,fluorescent sensors,visual detection,Cu2+,quantum dots,electrospinning
更新于2025-09-16 10:30:52
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PEGylation of protein-imprinted nanocomposites sandwiching CdTe quantum dots with enhanced fluorescence sensing selectivity
摘要： Fluorescent sensors combining the selective recognition of protein molecularly imprinted polymers (MIPs) and the fluorescent sensing of quantum dots (QDs) have been studied considerably, but their fluorescence sensing selectivity for the target proteins remains to be increased. Herein, we propose a strategy for increasing the sensing selectivity by post-imprinting PEGylation of surface protein-imprinted nanocomposites with embedded QDs. With bovine hemoglobin (BHb) as a model protein template, protein MIP nanolayers were anchored over the CdTe QD decorated SiO2 nanoparticles by the sol–gel process using aminopropyltriethoxy silane and tetraethoxysilicane. PEG chains were then grafted onto the surface of the imprinted nanostructures via the nucleophilic reaction of the surface amine groups with N-hydroxysuccinimide ester-terminal methoxy-PEG, followed by template removal. The resultant PEGylated sensors showed significantly improved aqueous dispersion stability compared with the non-PEGylated controls. More importantly, such PEGylation greatly increased the fluorescence response selectivity, with the Stern–Volmer equation based imprinting factor increasing from 2.7 to 5.4. The PEGylated sensors were applied to determine BHb in bovine serum samples with satisfactory recoveries at three spiking levels ranging from 94.3 to 103.7%, indicating their potential application in real samples.
关键词： PEGylation,Fluorescent sensors,Protein molecularly imprinted polymers,Quantum dots,Stern–Volmer equation,Bovine serum samples,Sol–gel process,Bovine hemoglobin
更新于2025-09-16 10:30:52
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Comprehensive Supramolecular Chemistry II || Polymers and Molecular Wires as Chemical Sensors
摘要： Sensors provide a critical interface between humans and the world around them. A sensor, according to the Oxford English dictionary, is “a device that detects or measures a physical property and records, indicates, or otherwise responds to it.” A sensor responds to an external stimulus and converts it into a signal that can be recorded. The human body has at least ?ve sets of sensors, i.e., nose, tongue, ears, eyes, and skin; and human beings sense the world by their smell, taste, hearing, sight, and touch. Examples of some commercially available sensors include temperature sensors, pressure sensors, ?ow sensors, stress/strain sensors, and conductivity sensors.
关键词： Polymers,Fluorescent Sensors,Molecular Wires,Chemical Sensors,Metallopolymers
更新于2025-09-11 14:15:04
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Polymer-Bound 4-Pyridyl-5-hydroxyethyl-thiazole Fluorescent Chemosensors for the Detection of Organophosphate Nerve Agent Simulants
摘要： Fluorescent sensors have been synthesized for organophosphate nerve agent detection. The resulting 4-pyridyl-5-hydroxyethyl structures react with organophosphate nerve agent simulants such as diethylchlorophosphate and diisopropylfluorophosphate and cyclize to form a dihydroquinolizinium ring that results in an increased fluorescence response to long-wave UV excitation. These sensors have been functionalized with monomeric substitutions that allow for covalent incorporation into a polymer matrix for organophosphate detection to develop a fieldable sensor. In addition, inclusion of silicon dioxide into the polymer matrix eliminated false-positive responses from mineral acids, greatly advancing this class of sensors.
关键词： silicon dioxide,dihydroquinolizinium ring,organophosphate nerve agent detection,polymer matrix,Fluorescent sensors
更新于2025-09-10 09:29:36
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Comprehensive Supramolecular Chemistry II || Fluorescent Sensors Based on Indicator Displacement
摘要： Indicator displacement assays (IDAs) provide a different, more versatile approach to chemical sensing. In these systems, introduced to supramolecular chemists by Inouye, and popularized by Anslyn soon thereafter, there is no covalent linkage between the receptor and the indicator moieties. Instead, the indicator is typically chosen to be capable of binding at the same position in the receptor as the analyte, therefore establishing a competition between the indicator and the analyte for the receptor’s binding site. One typically prepares a receptor–indicator complex as the sensing system, which is then exposed to the analyte. The analyte displaces the indicator from the receptor, either by way of its stronger affinity or through mass action, thereby freeing the indicator back into the solution bulk. Decomplexation is typically accompanied by drastic changes in one or more macroscopic properties of the indicator (e.g., color, absorbance, fluorescence, electrochemical properties): monitoring this property allows the experimenter to follow the otherwise silent binding event between the analyte and the receptor.
关键词： Supramolecular Chemistry,Indicator Displacement,Chemical Sensing,Fluorescent Sensors
更新于2025-09-10 09:29:36
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Comprehensive Supramolecular Chemistry II || Fluorescent Sensors for Biological Metal Ions
摘要： All living organisms require metals. They have vital roles as catalysts, osmotic regulators, signaling molecules, and transport molecules. Many different metals are present in the human body, and carry out a range of essential functions: for example, oxygen travels in the blood bound to iron in hemoglobin, neurons communicate by changing their sodium and potassium levels, and metal catalysts like manganese in superoxide dismutase speed up biochemical reactions.1 Although metals are so essential, they make up less than 3% of the human body by weight. The most abundant metals found in the body belong to periodic groups I and II, including calcium (1.5%), potassium (0.4%), sodium (0.2%), and magnesium (0.1%). Essential transition metals are considered to be trace elements because they collectively make up less than 0.1% of body mass. These include zinc, chromium, vanadium, cobalt, copper, manganese, molybdenum, and tin.2,3
关键词： Fluorescent Sensors,Biological Metal Ions,Fluorescence Imaging,Metal Probes,Ratiometric Probes
更新于2025-09-10 09:29:36
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Streptavidin-conjugated gold nanoclusters as ultrasensitive fluorescent sensors for early diagnosis of HIV infection
摘要： We have engineered streptavidin-labeled fluorescent gold nanoclusters to develop a gold nanocluster immunoassay (GNCIA) for the early and sensitive detection of HIV infection. We performed computational simulations on the mechanism of interaction between the nanoclusters and the streptavidin protein via in silico studies and showed that gold nanoclusters enhance the binding to the protein, by enhancing interaction between the Au atoms and the specific active site residues, compared to other metal nanoclusters. We also evaluated the role of glutathione conjugation in binding to gold nanoclusters with streptavidin. As proof of concept, GNCIA achieved a sensitivity limit of detection of HIV-1 p24 antigen in clinical specimens of 5 pg/ml, with a detection range up to1000 pg/ml in a linear dose-dependent manner. GNCIA demonstrated a threefold higher sensitivity and specificity compared to enzyme-linked immunosorbent assay for the detection of HIV p24 antigen. The specificity of the immunoassay was 100% when tested with plasma samples negative for HIV-1 p24 antigen and positive for viruses such as hepatitis B virus, hepatitis C virus, and dengue. GNCIA could be developed into a universal labeling technology using the relevant capture and detector antibodies for the specific detection of antigens of various pathogens in the future.
关键词： HIV infection,immunoassay,gold nanoclusters,early diagnosis,fluorescent sensors
更新于2025-09-10 09:29:36