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1.
In this study, a multiplex fluorescence sensor for successive detection of Fe 3+, Cu 2+ and Hg 2+ ions based on “on–off” of fluorescence of a single type of gold nanoclusters (Au NCs) is described. Any of the Fe 3+, Cu 2+ and Hg 2+ ions can cause quenching fluorescence of Au NCs, which established a sensitive sensor for detection of these ions respectively. With the introduction of ethylene diamine tetraacetic acid (EDTA) to the system of Au NCs and metal ions, a restoration of fluorescence may be found with the exception of Hg 2+. A highly selective detection of Hg 2+ ion is, thus, achieved by masking Fe 3+ and Cu 2+. On the other hand, the masking of Fe 3+ and Cu 2+ leads to the enhancement of fluorescence of Au NCs, which in turn provides an approach for successive determination of Fe 3+ and Cu 2+ based on “on–off” of fluorescence of Au NCs. Moreover, this assay was applied to the successful detection of Fe 3+, Cu 2+ and Hg 2+ in fish, a good linear relationship was found between these metal ions and the degree of quenched fluorescent intensity. The dynamic ranges of Hg 2+, Fe 3+ and Cu 2+ were 1.96 × 10 −10–1.01 × 10 −9, 1.28 × 10 −7–1.27 × 10 −6 and 1.2 × 10 −7–1.2 × 10 −6 M with high sensitivity (the limit of detection of Fe 3+ 2.0 × 10 −8 M, Cu 2+ 1.9 × 10 −8 M and Hg 2+ 2 × 10 −10 M). These results indicate that the assay is suitable for sensitive detection of these metal ions even under the coexistence, which can not only determine all three kinds of metal ions successively but also of detecting any or several kinds of metal ions. 相似文献
2.
A fluorescent organic small molecule, hexaphenylsilole (HPS), has been used as a sensing material, while a HPS/polymethyl methacrylate composite film with a lotus leaf like structure is prepared by a simple electrospin method. The film shows high stability and excellent sensitivity for the metal ions Fe 3+ and Hg 2+, respectively. The special surface morphology containing micro‐/nanocomposite structure is attributed to the exhibition of these unusual properties. 相似文献
3.
The synthesis of a novel, and highly selective Fe 3+ ion sensor based on anthrone-spirolactam and its quinoline hybrid ligand is reported. The designed ligand displayed selective detection of Fe 3+ ions with enhanced fluorescence emission. The complexation of Fe 3+ ion led to a red shift of 32 nm from 420 nm to 452 nm, and a several fold increase in intensity with fluorescent green emission. The complexation (detection) of Fe 3+ ions with ligand resulted in chelation enhanced fluorescence and intramolecular charge transfer through the inhibition of C=N isomerization. This hybrid sensor shows high sensitivity and selectivity, spontaneous response, and works on a wide pH range a minimum detection limit of 6.83 × 10 −8 M. Importantly, the sensor works through the fluorescence turn-on mechanism that overcomes the paramagnetic effect of Fe 3+ ions. The binding mechanism between the ligand and the Fe 3+ ions was established from the Job's plot method, optical studies, Fourier transfor infrared spectroscopy, NMR titration, fluorescence life-time studies, and density functional theory optimization. The sensor displayed excellent results in the quantification of Fe 3+ ions from real water samples. Furthermore, due to its biocompatibility nature, fluorescent spotting of Fe 3+ ions in live cells revealed its bioimaging applications. 相似文献
4.
我们方便地合成了上沿修饰四丹磺酰胺基团的杯[4]芳烃衍生物1,发现该化合物在含50%水的乙腈中显示出对汞离子高选择性和灵敏性的识别作用,竞争实验表明多数金属离子对其检测干扰较小。机理研究结果表明荧光萃灭源于由丹磺酰胺基团到汞离子的光致电子转移过程。另外,通过研究1和1-Hg2+的荧光衰减实验,以及对比双丹磺酰胺杯[4]芳烃2和单丹磺酰胺杯[4]芳烃3对汞离子的识别作用,发现化合物1的四丹磺酰胺基团具有很好的预组织和协同作用。化合物1对汞离子的检测限为3.41×10-6 mol·L-1,这可以使1成为一个潜在的汞离子荧光化学传感器。 相似文献
5.
A new fluorescent sensor based on the BODIPY fluorophore and the carboxyl-thiol metal bonding receptor for Hg 2+ was designed and synthesized. The sensor is highly selective for Hg 2+ (about 630-fold fluorescence enhancement) over relevant competing metal ions, sensitive to ppb levels of Hg 2+ (with detection limit of 5.7?nM), and fast response toward Hg 2+ (within 30?s) in aqueous solution. 相似文献
6.
2-Amino-6-methyl-4-phenyl-nicotinonitrile 1, a 2-aminopyridine-based fluorescent compound, was found to be a fluorescent chemosensor for the detection of Fe 3+ and Hg 2+ ions over a number of other metal ions. Compound 1 was synthesized in one step using a multicomponent reaction, and characterized using common spectroscopic tools. During Fe 3+/Hg 2+ sensing the compound 1 followed a ‘switch-off’ mechanism. Further, compound 1 could sense Fe 3+ over Hg 2+ by its distinct absorption and fluorescence quenching behaviors. 1:1 complex formation of 1 with Fe 3+ and Hg 2+ was clearly understood from Job’s plot. The present work brings additional evidence on the importance of multicomponent reactions which could lead to the development of fluorescence chemosensor in one step for the selective detection of biologically important metal ions. 相似文献
7.
Metal cations can be selectively detected by restoring and quenching the fluorescent intensity of an “ON–OFF” gold nanocluster (Au NC ) sensor. The fluorescent intensity of Au NCs with metal cations can be restored by chelating with ethylenediaminetetraacetic acid except for Hg 2+ ions. A highly selective detection of Hg 2+ ion is also achieved under the coexistence of Fe 3+ or Cr 3+ ions. This assay was applied successfully for detecting Hg 2+ in a water sample. The dynamic range of the system was 1 ppm to 25 ppb, and the limit of detection was 25 ppb. 相似文献
8.
A new thiacalix[4]arene derivative in a 1,3-alternate conformation bearing four naphthalene groups through crown-3 chains has been synthesized, which exhibits high selectivity toward Hg 2+ by forming a 1:2 complex, among other metal ions ( Na +, K +, Mg 2+, Ba 2+, Ca 2+, Sr 2+, Cs +, Mn 2+, Fe 2+, Cd 2+, Co 2+, Ni 2+, Cu 2+, Li +, and Zn 2+) with a low detection limit (3.30×10 ?7 M). The metal ion-binding properties were studied by fluorescence, AFM, and 1H NMR spectroscopy. The in situ prepared [Hg 2++L] complex shows well recognition ability for cysteine with a low detection limit (2.23×10 ?7 M) through fluorescence turning on. The mechanism of fluorescence turning on is the host L releasing from [L+Hg 2+] for [Cys+Hg 2+] complex formed. Thus the paper reports secondary-sensor design: Hg 2+ as a first sensor for [L+Hg 2+] form, cysteine as a second sensor for Hg 2+ releasing from the [L+Hg 2+] complex after cysteine adding in. 相似文献
9.
A new phenothiazine-based sensor PHE-Ad for monitoring Hg 2+ has been designed and synthesized based on the intramolecular charge transfer (ICT) mechanism. The probes were characterized by FTIR, 1H NMR, and HRMS, and their optical properties were detected by UV and FL. It's showed the probes detection of Hg 2+ compared to other metal ions (Mg 2+, Cu 2+, Hg 2+, Ag +, Co 2+, Cr 3+, Al 3+, Ni 2+, Zn 2+, Ca 2+, Fe 3+, Fe 2+, K +, Na +, and Cd 2+) based on the test results. Besides, the detection limits were determined to be 2.12 × 10 −8 M through the standard curve plot. In addition, sensor PHE-Ad shows high selectivity and sensitivity for Hg 2+ with a fast response in a suitable pH range. Furthermore, taking into account its good “turn-on” fluorescent sensing behavior and low cell cytotoxicity, PHE-Ad was successfully applied to detect and image Hg 2+ in real water samples and living cells, which shows great potentials for application in environmental and biological systems. 相似文献
10.
A pyrene based chemosensor was designed and synthesized. The pyrene fluorophore was connected with a pyridine unit through a Schiff base structure to give the sensor ( L). L was tested with a variety of metal ions and exhibited high colorimetric selectivities for Cu 2+ and Fe 3+ over other ions. Upon binding with Cu 2+ or Fe 3+, L showed an obvious optical color change from colorless to pink for Cu 2+ or orange for Fe 3+ over a wide pH range from 3 to 12. Moreover, the fluorescence of L at 370 nm decreased sharply after bonding with Fe 3+, while other metal ions including Cu 2+ had no apparent interference. Thus, using such single chemosensor, Cu 2+ and Fe 3+ can be detected independently with high selectivity and sensitivity. The limits of detection toward Cu 2+ and Fe 3+ were 8.5 and 2.0 μM, respectively. DFT calculation results also proved the formation of stable coordination complexes and the phenomenon of fluorescence quenching by Fe 3+. Furthermore, L was also successfully used as a bioimaging reagent for detection of Fe 3+ in living cells. 相似文献
11.
Heavy metal ions such as Hg and Pb are hazardous due to very high toxicity, mobility, and ability to accumulate through the food chain or atmosphere in the environment system. Therefore, ultrasensitive determination of mercury and lead is important to provide an evaluation index of ions in aqueous environment. This paper describes the investigation of surface modified quantum dots (QDs) as a sensing receptor for Hg 2+ and Pb 2+ ion detection by optical approach. Water-soluble L-cysteine-capped CdS QDs have been synthesized in aqueous medium. These functionalized nanoparticles were used as a fluorescence sensor for Hg 2+ and Pb 2+ ions, involved in the fluorescence quenching. The effect of foreign ions on the intensity of CdS QDs showed a low interference response toward other metal ions except Cu 2+ and Fe 2+ ions. The limit of detection (LOD) of this system is found to be 1.0 and 3.0 nM for Hg 2+ and Pb 2+ ions, respectively. 相似文献
12.
In this study, a nanocomposite consisting of three-dimensional reduced graphene oxide (3D-rGO) and plasma-polymerized propargylamine (3D-rGO@PpPG) was prepared and used as a highly sensitive and selective DNA sensor for detecting Hg 2+. Given the high density of amino groups in the resultant 3D-rGO@PpPG nanocomposite, thymine-rich and Hg 2+-targeted DNA was preferentially immobilized on the fabricated sensor surface via the strong electrostatic interaction between DNA strands and the amino-functionalized nanocomposites, followed by detecting Hg 2+ through T–Hg 2+–T coordination chemistry between DNA and Hg 2+. The results of electrochemical measurements revealed that the anchored amount of DNA strands anchored on the 3D-rGO@PpPG nanofilm surface affects the determination of Hg 2+ in aqueous solution. It showed high sensitivity and selectivity toward Hg 2+ within concentrations ranging from 0.1 to 200 nM and displayed a low detection limit of 0.02 nM. The new strategy proposed also provides high selectivity of Hg 2+ against other interfering metal ions, good stability, and repeatability. The excellent applicability of the developed sensor confirms the potential use of plasma-modified nanofilms for the detection of heavy metal ions in real environmental samples and water. 相似文献
13.
Two novel rhodamine-based fluorescence enhanced molecular probes (RA 1 and RA 2) were synthesized, which were both designed as comparative fluoroionophore and chromophore for the optical detection of Hg 2+. The recognizing behaviors were investigated both experimentally and computationally. They exhibited high selectivity and sensitivity for Hg 2+ over other commonly coexistent metal ions in CH 3CN/H 2O (1:1, V/ V) solution. Test shows that hydroxy benzene of rich electron was beneficial to the chelate of Hg 2+ with sensors. The detection limit was measured to be at least 0.14 μmol/L. After addition of Hg 2+, the color changed from colourless to pink, which was easily detected by the naked eye in both solution and hydrogel sensor. 相似文献
14.
In this study, kumquat was first time used for synthesizing carbon dot structures (CDs) with the hydrothermal method. These newly synthesized CDs was characterized structurally and optically. The ion sensor application of the new CDs was carried out using 20 different metal ions. It was observed that CDs have high selectivity only for Fe3+ ions among the metal ions studied. Detection limit for Fe3+ ions was calculated as 0.70 µM. The results showed that these new CDs are highly selective against Fe3+ ions and have a very short response time such as 0.5 min. The Fe3+ ions selectivity of CDs was tested on real (tap water) samples. The results exhibited that this new CDs, obtained with green synthesis from Kumquat fruit without using chemical agents in one-pot simple and economical process, can be used as fluorometric sensor for detection of Fe3+ ions with high selectivity and sensitivity, low detection limit and rapid response time. 相似文献
15.
Nanostructured polypyrrole (PPy) film doped with Tiron was electrodeposited from aqueous solution on the surface of transparent electrode and used for sensitive, selective and rapid electrically controlled fluorescence detection of Fe 3+ in aqueous media. The fluorescence intensity of PPy-Tiron film decreases linearly in the presence of Fe 3+ by applying negative potential over a concentration range from 5.0 × 10 −8 to 1.0 × 10 −6 mol L −1, with a relatively fast response time of less than 30 s at pH 7.4. The detection is not affected by the coexistence of other competitive metal ions such as Al 3+, Ce 3+, Tl 3+, La 3+, Bi 3+, Cr 2+, Mn 2+, Fe 2+, Co 2+, Ni 2+, Cu 2+, Zn 2+, Cd 2+, Hg 2+, Pb 2+, Na +, K +, Mg 2+, Ca 2+, Sr 2+ and Ba 2+. The proposed electro-fluorescence sensor has a potential application to the determination of Fe 3+ in environmental and biological systems. The fluorescent thin film sensor was also used as a novel probe for Fe 3+/Fe 2+ speciation in aqueous solution. 相似文献
16.
A novel organic–inorganic silica‐based fluorescent probe was designed, synthesized and characterized by different techniques such as XRD, BET, TGA, and FT‐IR. The fluorescence properties of the probe were studied in the presence of a variety of metal‐ions in water. The results revealed that various metal‐ions negligibly vary the emission intensity of the probe except for Hg 2+, which quenched the intensity dramatically. The selectivity of the probe toward Hg 2+ ion was further investigated in the presence of common competing metal‐ions and the results demonstrated the high selectivity of the probe toward Hg 2+ ion. The fluorescence emission of the probe was also studied as a function of the concentration of Hg 2+ ion. A nanomolar limit of detection was estimated for Hg 2+, indicating a high sensitivity. Furthermore, the probe showed INHIBIT‐type logic behavior with Hg 2+ and H + as inputs. Also, the optimum pH range was studied in addition to reversibility and real world applicability of the probe. 相似文献
17.
A rapid one-step preparation approach of silver nanoparticles (AgNPs) was reported by employing formamidinesulfinic acid as reducing agent and soluble starch as stabilizing agent. The formation of AgNPs was further confirmed by using UV–Vis absorption spectroscopy, X-ray diffraction spectroscopy and transmission electron microscopy techniques. The resultant AgNPs could be directly used for the colorimetric reaction with metal ions. The results showed that Al 3+, Cr 3+, Fe 3+ and Hg 2+ ions could induce the color change of AgNPs from yellow to pink (Al 3+), orange (Cr 3+) and colorless (Fe 3+ and Hg 2+), respectively, which can be observed by the naked eye. Based on these, a sensitive colorimetric sensor for Al 3+, Fe 3+, Cr 3+ and Hg 2+ ions detection was developed. 相似文献
18.
A new Schiff base fluorescence probe, 3-Allylsalicylaldehyde salicylhydrazone (L), for Mg 2+ was designed and synthesized. The fluorescence of the sensor L was enhanced remarkably by Mg 2+ with 2:1 binding ratio, and the binding constant was determined to be 1.02 × 10 7 M ?1. Probe L had high sensitivity for Mg 2+ in a solution of DMF/water (4:1, v/v, pH 7.5), and the detection limit was 4.88 × 10 ?8 mol/L. Common coexistent metal ions, such as K +, Na +, Ag +, Ca 2+, Zn 2+, Ba 2+, Bi 2+, Cu 2+, Ni 2+, Hg 2+, Fe 3+ , and Al 3+, showed little or no interference on the detection of Mg 2+ in solution. The fluorescence probe L, which was successfully used for the determination of trace Mg(II) in real samples, was shown to be promising for liquid-phase extraction coupled with fluorescence spectra. 相似文献
19.
A novel copper selective sensor 2 based on hydrazide and salicylaldehyde has been designed and prepared. Sensor 2 behaves a single selectivity and sensitivity in the recognition for Cu 2+ over other metal ions such as Fe 3+, Hg 2+, Ag +, Ca 2+, Zn 2+, Pb 2+, Cd 2+, Ni 2+, Co 2+, Cr 3+ and Mg 2+ in DMSO. The distinct color change and the rapid changement of fluorescence emission provide naked‐eyes detection for Cu 2+. The UV‐vis data indicate that 1:2 stoichiometry complex is formed by sensor 2 and Cu 2+. The association constant Ks was 3.51×10 4 mol ?1·L. The detection limitation of Cu 2+ with the sensor 2 was 2.2×10 ?7 mol·L ?1. The sensing of Cu 2+ by this sensor was found to be reversible, with the Cu 2+‐induced color being lost upon addition of EDTA. 相似文献
20.
This paper described an investigation of a novel eco-friendly fluorescence sensor for Hg 2+ ions based on N-acetyl-l-cysteine (NAC)-capped ZnS quantum dots (QDs) in aqueous solution. By using safe and low-cost materials, ZnS QDs modified by NAC were easily synthesized in aqueous medium via a one-step method. The quantitative detection of Hg 2+ ions was developed based on fluorescence quenching of ZnS QDs with high sensitivity and selectivity. Under optimal conditions, its response was linearly proportional to the concentration of Hg 2+ ions in a range from 0 to 2.4 × 10 −6 mol L −1 with a detection limit of 5.0 × 10 −9 mol L −1. Most of common physiologically relevant cations and anions did not interfere with the detection of Hg 2+. The proposed method was applied to the trace determination of Hg 2+ ions in water samples. The possible quenching mechanism was also examined by fluorescence and UV-vis absorption spectra. 相似文献
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