查找使用阿拉丁产品的科研文献

A novel fluorescent “OFF-ON” sensing strategy for Hg (II) in water based on functionalized gold nanoparticles

Gufeng Li,Mingrong Lu,Shaoqing Li,Min Yang,Yuanling Zhang,Yanli Zhang,Hongbin Wang,Wenrong Yang

Mercury ion (Hg 2+ ) is a heavy metal pollutant that can affect the safety of water environment and endanger human health. A novel detection strategy (GNPs- L -Cys-Rh6G2) for Hg 2+ based on a fluorescence “OFF-ON” was proposed. Gold nanoparticles (GNPs) were assembled with l -cysteine ( L -Cys), which was used as a “bridge” to link with rhodamine 6G derivatives (Rh6G2). The fluorescence state transition of GNPs- L -Cys-Rh6G2 switching from “OFF”-“ON” was observed because Hg 2+ opened the spirolactam ring through a catalytic hydrolysis mechanism. The fluorescence signal of the GNPs- L -Cys-Rh6G2 system mixed with Hg 2+ in the concentration range of 10–100 μM was analyzed and determined with a limit of detection (LOD) of 2 μM ( S/N  = 3). Moreover, the spiked Hg 2+ concentration in real water samples were successfully quantified by GNPs- L -Cys-Rh6G2, which was in line with the ideal average recovery rate and relative standard deviation. The proposed strategy exhibited high specificity, sensitivity and stability, providing a novel sensing platform for heavy metal ions detection in water environment.

Chitosan based fluorescent interpenetrating network polymeric probes for the sensitive detection and efficient removal of Hg+ ions

Junyu Chen,Lian Duan,Jinlei Xu,Xinjian Cheng

Chitosan (CS) based interpenetrating polymer network (IPN) is formed by cross-linking of CS with another polymer. It exhibits the ability of detecting environmental pollutants. In this work, the cross-linked CS was used as the network skeleton, the RAFT agent could produce an interpenetrating network with CS during the polymerization process, thereby forming a fluorescent hydrogel-type IPN (CS-Cy-PMAm and CS-Cy-PHD). The basic properties of CS-based hydrogels were analyzed by NMR, MS, FT-IR, SEM, TEM, AFM, and so on. This hydrogel prepared by in-situ synthesis technology not only has excellent film-forming properties but also EGME and toluene solvent molecules can significantly enhance the fluorescence of the hydrogel by infiltrating or squeezing the CS network. Due to the chelation of C N, C O, and thioester bonds with Hg + to block the PET process, the hydrogel exhibited a highly sensitive 46-fold fluorescence enhancement up the Hg + addition. The detection limit (LOD) of Hg + was 13 nM, and the adsorption capacity was 84.0 mg·g −1 . At the same time, the fluorescent film is made into a colorimetric card, which can realize real-time and portable detection of Hg + . This method expands the application of CS-based IPNs in environmental science and engineering.

Framework-derived Fe2O3/Mn3O4 nanocubes as electrochemical catalyst for simultaneous analysis of Cu(II) and Hg(II)

Jinrui Li,Zhongxin Zhuang,Zheng Guo,Zhonggang Liu,Xingjiu Huang

Exploiting advanced bimetallic oxide as sensing materials for electroanalysis offers new opportunity to improve the electrochemical performance, but still presents a tough challenge. Herein, we synthesized the uniform Fe 2 O 3 /Mn 3 O 4 nanocubes from a framework structure in a facile approach, which were developed as the electrochemical catalyst for individual and simultaneous analysis of Cu(II) and Hg(II) in 0.1 M HAc-NaAc buffer solution (pH5.0). It showed the excellent electrochemical behavior for the simultaneous analysis Cu(II) and Hg(II) with high sensitivities of 69.29 and 190.55 μA μM cm −2 . The corresponding limit of detection values (LODs) were calculated to be 3.94 nM and 1.39 nM, respectively. The excellent electrochemical behavior of Fe 2 O 3 /Mn 3 O 4 could be attributed to the large specific surface area, which could provide a large number of adsorption sites for Cu(II) and Hg(II). Meanwhile, the bimetallic Fe and Mn atoms arranged in the porous nanocubes could offer a synergistic effect and improve the electrochemical activity. Moreover, it could be successfully applied for the simultaneous analysis of Cu(II) and Hg(II) in real water samples with the favorable recovery rate. The results confirmed that the Fe 2 O 3 /Mn 3 O 4 nanocubes could serve as a reliable platform for the simultaneous analysis of Cu(II) and Hg(II).

CdTe quantum dot-based fluorescent probes for selective detection of Hg (II): The effect of particle size

Jian Zhu,Zhu-Jun Zhao,Jian-Jun Li,Jun-Wu Zhao

Mercury ions-induced fluorescence quenching properties of CdTe quantum dots (QDs) have been studied using the fluorescence spectroscopic techniques. By using the hydrothermal method , the CdTe QDs with different particles sizes from 1.98 to 3.68   nm have been prepared, and the corresponding fluorescence emission wavelength is changed from 518 to 620   nm. The fluorescence of QDs is enhanced after linking Bovine serum albumin (BSA) onto the surface of the QDs. Experimental results show that the fluorescence intensity of BSA-coated CdTe QDs could be effectively quenched when Hg 2   + react with BSA-coated CdTe QDs. Interestingly, both the sensing sensitivity and selectivity of this fluorescence probe could be improved when the particle size of the QDs decreases. Thus the BSA-coated CdTe QDs with green fluorescence emission have better advantages than the BSA-coated CdTe QDs with red fluorescence for Hg 2   + detection. Interference experiment results indicate that the influence from other metal ions could be neglected in the detection, and the Hg 2   + could be specifically detected. By using this BSA-coated CdTe QDs-based fluorescence probe, the Hg 2   + could be detected with an ultra-low detection limit of nanomole level, and the linear range spans a scope from 0.001 to 1   μmol/L.

Critical Addition Point-Based Trace Sensing of Hg²+ Through Surface Plasma Polaritons Properties Analysis of Ag Nanoparticles

Xia Zhang,Yu-Ying Wang,Ya-Nan Xu,Meng-Xiao Xu,Hua-Ling Zhang,Guan-Xi Li

Adsorption behavior and mechanism of Hg (II) on a porous core-shell copper hydroxy sulfate@MOF composite

Ling Zhang,Jinghua Zhang,Xinglin Li,Cuijie Wang,Ajuan Yu,Shusheng Zhang,Gangfeng Ouyang,Yuanyuan Cui

Herein, a porous core-shell copper hydroxy sulfate@metal-organic framework decorated by 2,5-dimercapto-1,3,4-thiadiazol (DMTZ) was synthesized via a facile self-template strategy for the capture of Hg 2+ . The strategy of assembling MOF shell on copper hydroxy sulfate (CHS) core avoided the self-nucleation of MOF(Cu 3 (BTC) 2 ) in the solution and complex multistep procedures by means of in situ transformation the metal source CHS into well-defined Cu 3 (BTC) 2 crystal. The structure and properties of the DMTZ modified CHS@Cu 3 (BTC) 2 (CHS@Cu 3 (BTC) 2 -DMTZ) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA) and N 2 sorption–desorption isotherms (BET). The adsorption behavior followed Langmuir adsorption model and the maximum adsorption capacities for the removal of Hg 2+ was up to 627.6 mg g −1 . 99.96% Hg 2+ was rapidly captured by CHS@Cu 3 (BTC) 2 -DMTZ within 10 min from 40 mg L -1 to 0.014 mg L -1 . Meanwhile, not only X-ray photoelectron spectroscopy (XPS) but also Raman spectra verified the selective and strong interaction between Hg 2+ and thiol/nitrogen-containing functional groups of DMTZ on CHS@Cu 3 (BTC) 2 -DMTZ. These results manifested that this novel thiol-functionalized MOF adsorbent had superior adsorption capacity and selective for Hg 2+ .

Removal of Pb(II), Cd(II) and Hg(II) from aqueous solution by mercapto-modified coal gangue

Zhongbo Shang,LiWen Zhang,Xuyang Zhao,Shanhu Liu,Deliang Li

A low-cost mercapto-modified coal gangue (CG-SH) was fabricated by modification of coal gangue (CG) with (3-mercaptopropyl) trimethoxysilane. The structure and composition for as-prepared CG-SH were characterized by using X-ray diffraction (XRD), Fourier transfer infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray fluorescence (XRF). Results indicated that larger amounts of mercapto-groups (-SH) was successfully introduced onto CG, which followed by acted as active sites for the removal of heavy metal cations, such as Pb(II), Cd(II) and Hg(II). The factors that affected the adsorption equilibrium as well as the removal efficiency, i.e., contact time, initial concentration, pH and temperature, were investigated in detail. The adsorption isotherms for Pb(II), Cd(II) and Hg(II) were well fitted with Langmuir model. The maximum adsorption capacity of CG-SH for Pb(II), Cd(II) and Hg(II) were calculated to be 332.8, 110.4 and 179.2 mg g −1 , respectively. The adsorption for Pb(II), Cd(II) and Hg(II) on CG-SH could be well described by pseudo-second-order kinetic model . And thermodynamic analysis suggests that the adsorption process for Pb(II) is exothermal, while that for Cd(II) and Hg(II) are endothermal. The results suggest CG-SH have great potential to be used as efficient absorbent for the removal of heavy metal cations from water.

Highly enhanced adsorption for the removal of Hg(II) from aqueous solution by Mercaptoethylamine/Mercaptopropyltrimethoxysilane functionalized vermiculites

Lytuong Tran,Pingxiao Wu,Yajie Zhu,Lin Yang,Nengwu Zhu

Vermiculites modified with Mercaptoethylamine (MEA) and 3-Mercaptopropyltrimethoxysilane (MPTMS) were used as effective adsorbents for the removal of Hg(II) from aqueous solution. The physicochemical characteristics of the pristine and functionalized vermiculites were analyzed by XRD, BET, FTIR, SEM, TEM and Zeta potentials, confirming that the vermiculite was successfully functionalized by the organic ligands containing the thiol (SH) metal-chelating groups. Batch adsorption experiments demonstrated that the factors such as initial pH, contact time, temperature, coexisting cations and initial Hg(II) concentration could significantly influence the adsorption behaviors typically for VER and MEA-VER, whereas the adsorption capacity of MPTMS-VER showed negligible dependence on such factors. The maximum adsorption capacity of Hg(II) ions was greatly improved after functionalization, which was in the order of MPTMS-VER>MEA-VER>VER (286.29 μg g(-1), 176.33 μg g(-1), 99.95 μg g(-1), respectively). The adsorption isotherm could be well described with Langmuir model and the kinetic studies indicated that the adsorption process fitted well with the pseudo-second-order model. The calculated thermodynamic parameters suggested that the adsorption process was feasible and spontaneous. The adsorption mechanism of Hg(II) on thiol groups was studied through XPS analysis. Considering the favorable adsorption capacities, thiol-functionalized vermiculites show a promising application in the removal of Hg(II) from wastewater.

A homogeneous thiol-functionalized chitosan membrane as a DGT binding phase for trace Hg(II) determination in seawater

Xianghua Wu,Dongjun Li,Haiying Lin,Qingge Feng,Lixin Huang,Qiuyan Hu,Chun Lv,Jie He,Guanjian He

A homogeneous membrane enabled Hg(II) capture and trace-level Hg(II) determination. • S- and N-containing groups dominated Hg(II) binding with a capacity of 639.12 mg/g. • The assembled DGT achieved superior performance with additional correction. • Field trials in coastal aquaculture area yielded Hg(II) concentrations of 1.24–2.62 ng/L. Background Mercury is highly toxic. Hg(II) methylation produces methylmercury, which biomagnifies in aquatic food webs and poses neurological risks. Grab sampling may not represent average labile Hg(II) concentrations during deployment in estuarine and coastal aquaculture waters. Diffusive gradients in thin films (DGT) provides time-integrated measurements, but matrix interference and ion-dependent corrections limit some binding phases. Reliable monitoring requires a matrix-tolerant binding phase. Results A homogeneous thiol-functionalized chitosan membrane (CS-MSA/PVA) was fabricated as a DGT binding layer. The membrane exhibited a maximum Hg(II) capacity of 639.12 mg/g and high affinity at trace levels, with S- and N-containing sites jointly participating in binding. CS-MSA/PVA@DGT achieved 99.0–100.5% elution within 20 min using HCl-thiourea. Hg(II) was measured by hydride generation-atomic fluorescence spectrometry (HG-AFS). The method blank and LOD were 0.45 ± 0.094 ng and 0.28 ng/disc. Hg(II) accumulated linearly in ultrapure water, river water and seawater, with effective diffusion coefficients of 17.9, 16.8 and 16.2 × 10 −6  cm 2 /s, respectively. C DGT /C SOL remained within 0.90–1.10 across pH 3.6–9.6, ionic strength 0–800 mmol/L, fulvic acid below 25 mg/L, major seawater ions, and Mg 2+ /Cl − gradients, requiring no Mg 2+ or Cl − correction. Static and stepwise dynamic spike-recovery tests confirmed time-weighted average Hg(II) determination in river water and seawater ( C DGT /C SOL  = 0.91–1.08). After temperature and diffusive boundary layer correction, field DGT-labile Hg(II) concentrations were 1.24–2.62 ng/L, agreeing with purge-trap HG-AFS measurements within 10% deviation. Significance The homogeneous membrane combines efficient Hg(II) capture and quantitative elution with tolerance to coastal water matrices. CS-MSA/PVA@DGT supports labile Hg(II) monitoring and assessment of Hg exposure and aquaculture water quality. Download: Download high-res image (455KB) Download: Download full-size image

Green synthesis of fluorescent carbon nanospheres from chrysanthemum as a multifunctional sensor for permanganate, Hg(II), and captopril

Xuemei Dong,Minhui Wang,Yecang Tang

A simple and green method for the synthesis of fluorescent carbon nanospheres (CNs) was proposed using chrysanthemum as a natural precursor and ethylenediamine as the co-reagent. The prepared CNs show strong blue fluorescence in water with quantum yield of 13.7 %, and distinguished fluorescent stability against photobleaching and ion strength. Meanwhile, the fluorescence signal of CNs is reversible and sensitive to temperature in the range of 20–80 °C, which makes CNs useful as a temperature sensor. More importantly, the CNs can serve as excellent fluorescent sensors for detecting MnO 4 − and Hg 2+ with the detection limit of 0.72 and 0.26 μM, respectively. MnO 4 − quenches the fluorescence of CNs through inner filter effect and static quenching mechanism, while Hg 2+ forms a stable complex with the amino group on the surface of CNs, resulting in the fluorescence quenching of CNs. However, the stronger affinity between Hg 2+ and captopril (Cap) results in the fluorescence quenched by Hg 2+ recovery after the addition of Cap. Thus, the CNs-Hg 2+ system is employed as a novel sensitive and selective fluorescence “turn-on” sensor for Cap in the range of 0–75 μM. Inspired by the sensing results, the developed sensors were successfully used for the determination of MnO 4 − , Hg 2+ in river water samples and Cap in the pharmaceutical and urine samples.

Highly efficient and selective Hg(II) removal from water by thiol-functionalized MOF-808: Kinetic and mechanism study

Chenghan Ji,Yi Ren,Hang Yu,Ming Hua,Lu Lv,Weiming Zhang

Mercury pollution poses a serious threat to the ecological environment and public health due to its high toxicity and persistence, but there is still a lack of rapid and effective Hg(II) removal technology, especially emergency response of Hg(II) leakage. Herein, an effective metal-organic framework adsorbent, MOF-808-SH, was fabricated by grafting thioglycollic acid on MOF-808 for Hg(II) removal. The MOF-808-SH demonstrated high adsorption capacity of 977.5 mg/g, impressively ultrafast adsorption kinetics (C 0  = 10 mg/L, removal > 99 % in 10 s) with a rate constant k of 36.89 g mg −1 min −1 , which is dozens of times faster than that of ever reported Hg(II) adsorbents. Batch experiments show that MOF-808-SH exhibits high selectivity toward Hg(II) with a distribution coefficient K d as high as 5.0×10 6 mL/g. Moreover, MOF-808-SH exhibits excellent recyclability with a negligible loss of capacity after 6 adsorption-regeneration cycles. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometry (XPS) unveil that the –SH groups in MOF-808-SH are the key adsorption sites, and specific inner-sphere coordination with Hg(II) is responsible for the high selectivity. In addition, large surface area, well-developed porous structures and high –SH loading of MOF-808-SH reasonably explains ultrafast kinetics and high adsorption capacity for Hg(II). This study indicates the potential of MOF-808-SH to remove Hg(II) from wastewater.

Pre-grafting effect on improving adsorption efficiency of cellulose based biosorbent for Hg (II) removal from aqueous solution

Ming Li,Siqi Zhang,Shiyu Cui,Kexin Qin,Yuling Zhang,Ping Li,Qianyong Cao,Huining Xiao,Qindan Zeng

Adsorption technique is considered to be an effective way to remove heavy metal species from aqueous solutions and cellulose based materials are widely used as good candidates of adsorbents. However, low grafting efficiency of functional groups has been a major challenge reducing the heavy metal adsorption capacity of cellulose based adsorbents. In this work, a diethylenetriaminepentaacetic acid modified cellulose is synthesized by an efficient catalyzed approach on the basis of glycidyl methacrylate pre-grafting (G-DMC). As a contrast, epichlorohydrin is employed as coupling side chain to react with the same polyacid (DMC) to evaluate the effect of pre-grafting. It is verified that “pre-grafting technique” significantly improves the load efficiency of polyacid and enhances the adsorption performance that the as-prepared adsorbent using pre-grafting technique shows much higher adsorption capacity ( Q m ) towards mercury in aqueous solutions with Q m of 443.8 mg/g, which is 3.5 folds of the epichlorohydrin grafted one. In addition, the kinetic adsorption experiments confirm that G-DMC achieves its adsorption equilibrium in a shorter time of 10 min. After five cycles of regeneration process, G-DMC could maintain 88.13% of its original adsorption capacity. Moreover, the live/dead cell fluorescence staining demonstrates the good biological safety of the material that the cell viability of murine L929 fibroblasts could retain close to 100% after 24 h of cultivation with G-DMC. Thus, this pre-grafting strategy is expected to provide an environmentally friendly method to amplify the adsorption capacity of the designed receptor for guest species.