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1.
An aggregation-induced emission (AIE)-active fluorescent chemosensor based on a tetraphenylethene (TPE) unit has been successfully designed and synthesized. Interestingly, the luminogen could detect Zn 2+ selectively in a THF solution with the detection limit of 1.24 × 10 −6 mol L −1. Meanwhile, the luminogen could also detect Hg 2+ selectively in a THF-water mixture with the water content of 90%, and the detection limit was 2.55 × 10 −9 mol L −1. Furthermore, the solid-state mechanochromic fluorescence behavior of the luminogen was investigated systematically. Indeed, the AIE-active luminogen also exhibited reversible mechanofluorochromic phenomenon involving fluorescent color change from blue to green, and powder X-ray diffraction results indicated that the switchable morphology conversion between crystalline and amorphous states was responsible for this mechanochromism phenomenon. 相似文献
2.
A low‐molecular‐weight fluorescent probe 1 (M.W. = 238.24) based on aurone was synthesized, and its application in fluorescent detection of Hg 2+ in aqueous solution and living cells was reported. It exhibited an “on–off” fluorescent response toward Hg 2+ in aqueous solution. Both the color and fluorescence changes of the probe were remarkably specific for Hg 2+ in the presence of other common metal ions, satisfying the selective requirements for biomedical and environmental monitoring application. The probe has been applied in direct measurement of Hg 2+ content in river water samples and imaging of Hg 2+ in living cells, which further indicates the potential application values in environmental and biological systems. 相似文献
3.
The heavy metal mercury (Hg) is a threat to the health of people and wildlife in many environments. Among various chemical forms, Hg 2+ salts are usually more toxic than their counterparts because of their greater solubility in water; thus, they are more readily absorbed from the gastrointestinal tract into circulation. Therefore, new chemical receptors for detecting Hg 2+ ions in circulation are needed. In this study, we developed a rhodamine-based turn-on fluorescence probe to monitor Hg 2+ in aqueous solution and in blood of mice with toxicosis. The chemodosimeter responds to Hg 2+ ions stoichiometrically, rapidly, and irreversibly at room temperature as a result of a chemical reaction that produces strongly fluorescent oxadiazole. The new fluorescent probe shows good fluorescence response, with high sensitivity and selectivity, toward Hg 2+ ions in aqueous solution and in blood from mice with toxicosis and facilitates the naked-eye detection of Hg 2+ ions. 相似文献
4.
Novel rhodamine B (RB) derivatives bearing mono and bis-boronic acid groups were investigated as Hg 2+ selective fluorescent and colorimetric sensors. These derivatives are first examples of reversible fluorescent chemosensors for Hg 2+ which utilized boronic acid groups as binding sites. Two new RB-boronic acid derivatives displayed selective ‘ Off- On’-type fluorescent enhancements and distinct color changes with Hg 2+. Selective fluorescent enhancement of two rhodamine derivatives was attributed to ring opening from the spirolactam (nonfluorescent) to ring-opened amide (fluorescent). 相似文献
5.
A new bipyridyl derivative 1 bearing rhodamine B as visible fluorophore was designed, synthesized and characterized as a fluorescent and colorimetric sensor for metal ions. Interaction with Cu 2+, Zn 2+, Cd 2+, Hg +, and Hg 2+ ions was followed by UV/Vis and emission spectroscopy. Upon addition of these metal ions, different colorimetric and fluorescent responses were observed. “Off-on-off” (Cu 2+, Zn 2+, and Hg 2+) and “off-on” (Hg + and Cd 2+) systems were obtained. Probe 1 was explored to mimic XOR and OR logic operations for the simultaneous detection of Hg +–Cu 2+ and Hg +–Zn 2+ pairs, respectively. DFT calculations were also performed to gain insight into the lowest-energy gas-phase conformation of free receptor 1 as well as the atomistic details of the coordination modes of the various metal ions. 相似文献
6.
An efficient strategy for simultaneously detecting and removing Hg 2+ from water is vital to address mercury pollution. Herein a supramolecular assembly G ⊂ H with photoluminescent properties is facilely constructed through the self-assembly of a functional pillar[5]arene bearing two N,N-dimethyldithiocarbamoyl binding sites ( H ) and an AIE-active tetraphenylethene derivative ( G ). Remarkably, the fluorescence of G ⊂ H can be exclusively quenched by Hg 2+ among the 30 cations due to the formation of non-luminous ground state complex and only L-cysteine can restore fluorescence in the common 20 amino acids. Meanwhile, the probe G ⊂ H has a considerable thermal and pH stability, a good anti-interference property from various cations, and a satisfactory sensitivity. More importantly, G ⊂ H exhibits a prominent capability of Hg 2+ removal with rapid capture rate (within 1 h) and excellent adsorption efficiency (98 %), as well as a highly efficient recyclability without losing any adsorption activity. 相似文献
7.
A small organic molecule P was synthesized and characterized as a fluorometric and colorimetric dual-modal probe for Hg 2+. The sensing characteristics of the proposed probe for Hg 2+ were studied in detail. A fluorescent enhancing property at 583 nm (>30 fold) accompanied with a visible colorimetric change, from colorless to pink, was observed with the addition of Hg 2+ to P in an ethanol-water solution (8:2, v/ v, 20 mM HEPES, pH 7.0), which would be helpful to fabricate Hg 2+-selective probes with “naked-eye” and fluorescent detection. Meanwhile, cellular experimental results demonstrated its low cytotoxicity and good biocompatibility, and the application of P for imaging of Hg 2+ in living cells was satisfactory. 相似文献
8.
In the present study, a dual recognition strategy for ultrasensitive detection of Hg 2+ was successfully developed for the first time based on aptamer functionalized sulfur quantum dots (Apt-SQDs). The developed Apt-SQDs not only retained the good fluorescence properties of quantum dots but also overcame the problem of poor selectivity of SQDs for heavy metal ions. This system used the dual recognition strategy, including the combination of S x2? and Hg 2+ and T-Hg 2+-T structures to excellently identify and capture Hg 2+, and an ultrahigh sensitivity fluorescent aptasensor was fabricated. The fluorescent aptasensor had a good response to Hg 2+ at concentrations ranging of 10 ?15 to 10 ?7 M with an ultralow limit of detection of 0.3 fM, and the response to other metal ions was far less than that to Hg 2+. It was successfully applied to detect Hg 2+ in nearby environmental water samples (tap water, lake water and river water) with a good recovery rate. Moreover, portable test papers that would be useful for Hg 2+ monitoring in environmental water were designed. The dual recognition strategy not only achieves ultrasensitive fluorescent detection of Hg 2+ but also provides a new insight into the further expansion of the application of SQDs. 相似文献
9.
We described herein a new AIE-active polymer sensor incorporating triazole moiety for Hg 2+ detection in aqueous solution. The polymer sensor P1 was synthesized from tetraphenylethene and diazidobenzene via click reaction. It shows typical AIE feature, and emits cyan fluorescence in the mixture of tetrahydrofuran and water, reaching the strongest fluorescence when the fraction of water ( fw) is 90%. In aqueous solution ( fw?=?90%), the polymer sensor can exhibit fluorescence quenching response towards Hg 2+ over other competing metal ions, with the fluorescence color changed from cyan to almost no emission, which can be clearly observed by the naked eyes under 365?nm UV lamp. 相似文献
10.
Novel 1,4-dihydropyridine (DHP) derivatives containing 3 carboxylic acid units are synthesized via cyclotrimerization of N-substituted β-aminoacrylates followed by basic hydrolysis of the triester. These DHP derivatives are readily soluble in aqueous media buffered at pH 8.0 and the solutions give blue fluorescent signals with quantum yields of 7–23%. One of these compounds, bearing a p-methoxyphenyl N-substituted group, shows specific fluorescent quenching with the mercuric ion (Hg 2+). The fluorescent signal of the DHP derivative decays over a period of minutes to hours depending on the Hg 2+ concentration, which implies that the sensing mechanism involves chemical reaction between the Hg 2+ ion and the DHP compound. The 1H NMR and MS data suggest that Hg 2+ mediates the oxidation of the DHP ring into a pyridinium ring. The event is useful for fluorescent detection of Hg 2+ at the micromolar level within 30 min, with a detection limit of 0.2 μM in aqueous medium. 相似文献
11.
A novel 8-hydroxyquinoline derivative 3 was synthesized. Significant fluorescent quenching was found in the presence of Cu 2+ and Hg 2+ with notably higher selectivity for Cu 2+ than Hg 2+. 相似文献
12.
A rhodamine spirolactam derivative ( 1) bearing a hydrophilic carboxylic acid group is developed as a fluorescent chemodosimeter for bivalent mercury ions (Hg 2+) in 100% aqueous solution. It exhibits a highly sensitive “turn-on” fluorescent response toward Hg 2+ with a 42-fold fluorescence intensity enhancement under 1 equiv. of Hg 2+ added. The chemodosimeter can be applied to the quantification of Hg 2+ with a linear range covering from 3.0 × 10 −7 to 1.0 × 10 −5 M and a detection limit of 9.7 × 10 −8 M. Most importantly, the fluorescence changes of the chemodosimeter are remarkably specific for Hg 2+ in the presence of other metal ions, which meet the selective requirements for practical application. Moreover, the experiment results show that the response behavior of 1 towards Hg 2+ is pH independent in neutral condition (pH 5.0–8.0) and the response is fast (response time less than 3 min). Furthermore, the ring-opening mechanism of the rhodamine spirolactam induced by Hg 2+ was supported by NMR, MS, and DFT theoretical calculations. In addition, the proposed chemodosimeter has been used to detect Hg 2+ in water samples and image Hg 2+ in living cells with satisfying results. 相似文献
13.
2-(2′,5′-Dihydroxy-phenyl)-4(3H)-quinazolinone (DHPQ), a new fluorescent dye that exhibits excited state intramolecular proton transfer (ESIPT) reaction and possesses good photophysical properties, is synthesised and used as fluorescent probe for detection of Hg 2+. Mercuric ions can be detected and quantitated by measuring the fluorescent intensity decrease of the probe. The decrease of fluorescence intensity of DHPQ upon the addition of Hg 2+ was attributed to the blocking of ESIPT reactions of DHPQ and quenching its fluorescence. The analytical performance characteristics of the proposed Hg 2+ probe were investigated. The probe can be applied to the quantification of Hg 2+ with a concentration range covering from 8.0?×?10 ?7 to 2.0?×?10 ?4?mol?L ?1, with a working pH range of 5.5–6.5. It shows excellent selectivity for Hg 2+ over other transition metal cations. The proposed method was testified for the Hg 2+ assay in river water samples with satisfying recoveries. 相似文献
14.
A new rhodamine-based Hg 2+-selective fluorescent probe ( I) was designed and synthesized. Compound I displays excellent selective and sensitive response to Hg 2+ over other transition metal ions in neutral aqueous solutions. I itself is a colorless, nonfluorescent compound. Upon addition of Hg 2+ to its solution, the thiosemicarbazide moiety of I undergoes an irreversible desulfurization reaction to form the corresponding 1,3,4-oxadiazole ( II), a colorful and fluorescent product, causing instantaneous development of visible color and strong fluorescence emission.
Based on this mechanism, a fluorogenic probe for Hg 2+ was developed. The fluorescence increases linearly with the Hg 2+ concentration up to 0.8 μmol L −1 with the detection limit of 9.4 nmol L − (3 σ). 相似文献
15.
The selective and efficient monitoring of mercury (Hg 2+) contamination found in the environment and ecosystem has been carried out. Thus, a new 1,8-naphthalimide-based fluorescent probe NADP for the detection of Hg 2+ based on a fluorescence enhancement strategy has been designed and synthesized. The NADP probe can detect Hg 2+ with high selectivity and sensitivity and a low detection limit of 13 nm . The detection mechanism was based on a Hg 2+-triggered deprotection reaction, resulting in a dramatic change in fluorescence from colorless to green at physiological pH. Most importantly, biological investigation has shown that the NADP probe can be successfully applied to the monitoring of Hg 2+ in living cells and zebrafish with low cytotoxicity. 相似文献
16.
In this study, we have developed a label-free, dual functional detection strategy for highly selective and sensitive determination of aqueous Ag + and Hg 2+ by using cytidine stabilized Au NCs and AuAg NCs as fluorescent turn-on and turn off probes, respectively. The Au NCs and AuAg NCs showed a remarkably rapid response and high selectivity for Ag + and Hg 2+ over other metal ions, and relevant detection limit of Ag + and Hg 2+ is ca. 10 nM and 30 nM, respectively. Importantly, the fluorescence enhanced Au NCs by doping Ag + can be conveniently reusable for the detection of Hg 2+ based on the corresponding fluorescence quenching. The sensing mechanism was based on the high-affinity metallophilic Hg 2+–Ag + interaction, which effectively quenched the fluorescence of AuAg NCs. Furthermore, these fluorescent nanoprobes could be readily applied to Ag + and Hg 2+ detection in environmental water samples, indicating their possibility to be utilized as a convenient, dual functional, rapid response, and label-free fluorescence sensor for related environmental and health monitoring. 相似文献
17.
A dual‐function fluorescence resonance energy transfer (FRET)‐based fluorescent and colorimetric probe was rationally fabricated from an energy donor coumarin moiety and an energy acceptor rhodamine moiety linked by a thiohydrazide arm for selective detection of Hg 2+ and Cu 2+. Two distinct mechanisms were used for the selective detection. Results revealed that probe 1 showed high fluorescent selectivity towards Hg 2+ and evident colorimetric selectivity for Cu 2+, which was suitable for ‘naked‐eye’ detection. 相似文献
18.
Mercury is one of the major toxic pollutants and has many adverse effects on human health. The main mercury species in the environment or in living organisms are inorganic mercuric ion (Hg 2+) and organic methylmercury (CH3Hg+). Detection of the two mercury ions is a particularly active topic in the molecular sensing field during the past decade. However, efficient sensors that can sensitively detect and discriminate the two species are rare. In this work, we adopt the concept of restriction of intramolecular rotations which is the basis of aggregation induced emission, and design a molecular probe with pyridyl group as the chelating unit and 1,8-naphthalimide as the fluorescent unit for the detection of both Hg 2+ and CH 3Hg +. When the probe is free in solution, it exhibits weak fluorescence because free intramolecular rotations of the 1,8-naphthalimide moieties non-radiatively annihilate its excited state. However, upon coordination with Hg 2+ or CH 3Hg +, the rotation of 1,8-naphthalimide moieties would be restricted due to the chelation between 1,8-naphthalimide and Hg 2+ or CH 3Hg +, leading to significantly enhanced fluorescent emission. The response induced by Hg 2+ is much stronger than CH 3Hg +; but for specific detection of CH 3Hg +, we introduced a T-rich DNA fragment which could completely mask Hg 2+ in solution. Furthermore, we have employed the sensor for confocal imaging of Hg 2+ and CH 3Hg +in immobilized cells. We expect the probe design tactics can be generally useful for sensing many other analytes. 相似文献
19.
A fluorescent and colorimetric sensor based on rhodamine 6 g (RD6g) was designed, synthesized, and characterized using microwave irradiation. The sensing behavior of this compound was studied by UV–visible and fluorescence spectroscopy. Sensor RD6g exhibits a high selectivity and an excellent sensitivity and is a dual-responsive colorimetric and fluorescent Hg2+-specific sensor in aqueous buffer solution. Mercury ions give rise to the development of a very fluorescent ring-open amide spirolactam system. The detection limit for Hg2+ was found to be 1.2?×?10?8 M. The binding ratio of RD6g-Hg2+ complex was determined to be 1:1 according to the Job’s plot. The reversibility of RD6g?Hg2+ complex has been achieved with CN? anions. The test strip based on RD6g was developed, which could be used as a suitable and methodical Hg2+ test kit.
相似文献
20.
A new anthracene fluorophore senses Hg 2+ selectively in aqueous solution. Among the metal ions examined, fluorescent chemosensor 1 shows selective large CHEQ effects with Hg 2+ and Ag + at pH 7. 相似文献
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