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1.
Talanta ; 236: 122835, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635225

RESUMO

Enrofloxacin (ENR) is a broad-spectrum fungicide that has been largely applied in pharmacy and animal-specific medicine. In this paper, a simple, novel and highly sensitive molecularly imprinted electrochemiluminescence (MIP-ECL) sensor based on mercaptopropionic acid-functionalized copper nanoclusters (MPA-Cu NCs) was developed to selectively detect enrofloxacin (ENR). MPA-Cu NCs prepared by a one-step method were used to modify the glassy carbon electrode. A molecularly imprinted polymer film containing the cavity was constructed after electropolymerization and elution. Under optimized conditions, the MIP-ECL sensor could detect ENR in the range of 0.1 nM-1 µM (R2 = 0.9863) with a low limit of detection of 27 pM, and the recovery rates of ENR in biological and lake water samples were 88.20-105.0%. The MIP-ECL sensor provided path to improve the stability issues of Cu NCs, which might open promising avenues to develop new ECL systems for biological analysis and environmental water monitoring.


Assuntos
Técnicas Biossensoriais , Impressão Molecular , Cobre , Eletrodos , Enrofloxacina
2.
Talanta ; 236: 122865, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635247

RESUMO

A sandwich-type electrochemical immunosensor was designed utilizing ferrocene-functionalized cuprous oxide superparticles (Au/Fc@CuxO SPs) as the signal label and graphene supported by hollow carbon balls (HCNs-GR) as the substrate. The CuxO SPs possess a superparticle structure with synergistic properties of isotropy and promising catalytic activity. Ferrocene (Fc) was deposited on the CuxO SPs to act as the electronic transmission medium. The Au/Fc@CuxO SPs played a pivotal role in improving the sensitivity of the immunosensor. The graphene supported by hollow carbon balls (HCNs-GR) was used to modify the electrode surface. The embedding of hollow carbon nanospheres (HCNs) reduced the decrease of the effective surface area caused by the stacking of graphene nanotubes. Meanwhile, the load of carbon balls further increases the surface area of graphene, enabled HCNs-GR to immobilize antibodies more effectively, improved the sensitivity of the immunosensor. The proposed immunosensor showed a linear range from 500 fg/mL to 100 ng/mL, with the detection limit to 25.7 fg/mL.


Assuntos
Técnicas Biossensoriais , Cobre , Técnicas Eletroquímicas , Imunoensaio , Metalocenos
3.
Food Chem ; 368: 130811, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34399177

RESUMO

Since excessive use of synthetic dyes has negative effects on human health, their determination in foodstuff is necessary. A sensitive sensor was developed based on copper BTC metal-organic framework (Cu-BTC MOF) and 1-ethyl-3-methylimidazolium chloride as an ionic liquid (IL) in an attempt to modify the carbon paste electrode and to improve the active surface area and electric conductivity so that electron transfer is faster for electro analysis. For the first time, high sensitivity, excellent conductivity, and appropriate selectivity of the electrochemical sensor have been evaluated as a new study for simultaneous determination of tartrazine, patent blue V, acid violet 7 and ponceau 4R. Excellent sensing performance of the proposed electrode was confirmed for patent blue V as an outstanding sensor, according to the low limit of detection of 0.07 µM, with a wide linear concentration range of 0.08 to 900 µM and reasonable recovery. In order to characterize the electrochemical behavior of electrode, cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy are used. Various techniques such as scanning electron microscopy (SEM) with energy dispersive X-Ray analysis (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) are employed to verify the structure of copper BTC metal-organic framework. The results revealed close packing of hierarchically porous nanoparticles and crystal structure of Cu-BTC MOF, with the edge of each particle around 20-37 nm. The analytical performance of the suggested electrochemical sensor is acceptable in foodstuffs such as jellies, condiments, soft drinks, and candies.


Assuntos
Líquidos Iônicos , Estruturas Metalorgânicas , Compostos Azo , Cobre , Técnicas Eletroquímicas , Eletroquímica , Eletrodos , Humanos , Naftalenossulfonatos , Corantes de Rosanilina , Tartrazina
4.
J Hazard Mater ; 421: 126688, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315634

RESUMO

Improper disposal of copper mining wastes can threaten the ecosystem and human health due to the high levels of potentially toxic elements released into the environment. The objective of this study was to determine the properties of Cu mining wastes generated in the eastern Amazon and their potential risks to environment and human health. Samples of forest soil and artisanal/industrial Cu mining wastes were collected and subjected to characterization of properties and pseudo-total concentrations of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, and Zn, in addition to chemical fractionation of Cu. The pH ranged from near neutrality to alkaline. Pseudo-total concentrations of Cu were high in all wastes, mainly in the artisanal rock waste, with 19,034 mg kg-1, of which 61% is concentrated in the most reactive fractions. Pollution indices indicated that the wastes are highly contaminated by Cu and moderately contaminated by Cr and Ni. However, only the artisanal rock waste is associated with environmental risk. Non-carcinogenic and carcinogenic human health risks were detected, especially from exposure to Cr in the artisanal rock waste. Prevention actions and monitoring of the artisanal mining area are necessary to avoid impacts to the local population.


Assuntos
Metais Pesados , Poluentes do Solo , Cobre/toxicidade , Ecossistema , Monitoramento Ambiental , Humanos , Resíduos Industriais/análise , Metais Pesados/análise , Mineração , Medição de Risco , Poluentes do Solo/análise
5.
J Colloid Interface Sci ; 605: 296-310, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34329981

RESUMO

This paper presents the design of a new type of intelligent and versatile all-in-one therapeutic nanoplatform for the co-delivery of chemotherapeutic drugs and photosensitizers to facilitate multimodal antitumor treatment; the system is based on hyaluronic acid (HA)-modified manganese dioxide (MnO2)-enveloped hollow porous copper sulfide (CuS) nanoparticles (CuS@MnO2/HA NPs). In this system, a CuS inner shell allows for the co-loading of doxorubicin (DOX) and indocyanine green (ICG) and induces photothermal effects, and a biodegradable MnO2 external shell affords on-demand tumor microenvironment (TME)-triggered release and catalase- andFenton-like activities. Moreover, the HA modification endows the system with a CD44 receptor-mediated tumor-targeting property. The formulated DOX and ICG co-loaded CuS@MnO2/HA (DOX/ICG-CuS@MnO2/HA) NPs were found to exhibit excellent photothermal performance both in vitro and in vivo. In addition, DOX/ICG-CuS@MnO2/HA NPs were found to display both TME and near-infrared (NIR)-responsive controlled release properties. The NPs also have a superior reactive oxygen species (ROS) generation capacity due to the combination of enhanced ICG-induced singlet oxygen and CuS@MnO2-mediated hydroxyl radicals. The cellular uptake, fluorescence imaging property, cytotoxicity, and thermal imaging of these NPs were also evaluated. In tumor-bearing mice, the DOX/ICG-CuS@MnO2/HA NPs displayeda superior antitumor efficacy (2.57-fold) as compared with free DOX. Therefore, the developed DOX/ICG-CuS@MnO2/HA NPs have a great potential for use as an all-in-one nanotherapeutic agent for the efficient and precise induction of chemo/photothermal/photodynamic/chemodynamic therapy with superior antitumor efficacy and fewer side effects.


Assuntos
Nanopartículas , Preparações Farmacêuticas , Animais , Cobre , Doxorrubicina/farmacologia , Ácido Hialurônico , Compostos de Manganês , Camundongos , Óxidos , Fármacos Fotossensibilizantes , Fototerapia , Sulfetos
6.
J Colloid Interface Sci ; 605: 906-915, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34375785

RESUMO

The search for ultrafast and simple methods to fabricate non-noble metal catalysts to boost electrocatalytic oxygen reduction reaction (ORR) is still ongoing. Herein, we demonstrate a one-step microwave-assisted heating method to prepare copper nitride/iron/iron carbide nanoparticle hybrids (CuNC/Fe/Fe3C/CNT). This ultrafast heating method induces plentiful carbon-wrapped metal and Fe3C nanoparticles that are attached to the surface of CNT and scattered nanosheets. The CuNC/Fe/Fe3C/CNT exhibit a half-wave potential (E1/2) of 0.886 V toward the ORR in alkaline solution, with 220 mV more positive E1/2 than that of CuNC/CNT and Fe/Fe3C/CNT respectively. The activity of as-prepared catalysts is discussed by investigating their structures and compositions and their relationship with the ORR performance. Detailed analysis results disclose that the high activity of the CuNC/Fe/Fe3C/CNT catalysts could be attributed to the interaction of CuNC and Fe/Fe3C species. To be specific, as the electron donor, Fe/Fe3C nanoparticles induce electron localization and promote the formation of Cu (δ + )-NC (0 < Î´ < 2), therefore leading to the improvement of the ORR performance. This work may offer an ultrafast way to construct efficient catalysts with enhanced ORR performance.


Assuntos
Carbono , Cobre , Catálise , Oxigênio
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120233, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34358780

RESUMO

Investigation of the adsorption properties croconic acid (CCA) with metal clusters (mC: Ag, Au and Cu) are reported using DFT method. CCA is found to form stable cluster with transition metal clusters of copper, silver and gold. The drug-cluster complexaton energy is slightly more for the copper nanocluster-drug complex. Non-covalent interaction analysis indicated that strong interactions and weak van der Waal interaction is present between drug and metal clusters. Dipole moment of the drug-gold cluster is found to be higher than that of the other systems. SERS studies demonstrates improved Raman signals for multiple wavenumbers of all CCA-metal cluster complexes. Mulliken charge analysis show that all CCA oxygen atom's charge changes due to the interactions with the mCs. Clustering of CCA with metal cages enhances the medicinal properties and the metal nanoclusters will act as a drug carrier of CCA.


Assuntos
Complexos de Coordenação , Prata , Cobre , Eletrônica , Ouro
8.
J Hazard Mater ; 421: 126812, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34396956

RESUMO

Chromium (Cr) pollution is a significant environmental concern with remediation challenge. Hexavalent chromium (Cr(VI)) is more toxic than trivalent chromium (Cr(III)) due to its mutagenicity and oncogenicity. In this investigation, a multi-functional material, copper nanoclusters (CuNCs)-halloysite nanotubes (HNT) composite (CuNCs@HNT), has been synthesised in an eco-friendly manner and utilised for Cr(VI) remediation. Advanced analytical tools confirmed the seeding of ultra-fine CuNCs onto HNT surfaces. The maximum adsorption capacity of CuNCs@HNT is 79.14 ± 6.99 mg/g at pH 5 ± 0.1 with an increment at lower pHs. This performance was comparable for real surface stream water as well as other reported materials. The pseudo-second-order kinetic-, intra-particle diffusion- and Freundlich isotherm models well fit the experimental data implying that the chemisorption, multiphase diffusion and multi-molecular layer distribution occurred during adsorption. The Fourier-transform infrared and the x-ray photoelectron spectra also ensured the transformation of Cr(VI) to Cr(III) indicating the material's suitability for concurrent adsorption and reduction of Cr(VI). While coexisting cations and anions did not overwhelm this adsorption, CuNCs@HNT was regenerated and reused five successive times in adsorption-desorption cycles without significant loss of adsorption capacity and material's integrity. Therefore, this multi-functional, biocompatible, low-cost and stable CuNCs@HNT composite may have practical application for similar toxic metals remediation.


Assuntos
Cobre , Poluentes Químicos da Água , Adsorção , Cromo/análise , Argila , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120257, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34411770

RESUMO

A novel fluorescent probe (DSD) was reasonably designed and synthesized with dansyl-labeled dipeptide (Dan-Ser-Asp-NH2). DSD featured remarkably large Stokes shift (230 nm) and perfect water solubility, and exhibited high selectivity and rapid recognition toward Cu2+via fluorescence quenching. The detection limit of DSD for Cu2+ was 2.4 nM, indicated that DSD has excellent sensitivity. In addition, the stoichiometry between DSD and Cu2+ were detected as 1:1 by fluorescence titration, Job's plot and ESI-HRMS data. As designed, DSD-Cu2+ system was able to sequentially detect CN- according to the displacement approach with fluorescence "off-on" response, and the detection limit for CN- was calculated to be 41.9 nM. Specifically, the response time of DSD with Cu2+ and CN- was less than 40 s, which rendered it suitable for real time detection in actual water samples. In addition, with the alternate addition of Cu2+ and CN-, the reversible cycles could be repeated for at least 10 times, indicated that DSD was a promising reversibility probe. DSD showed low toxicity and good biocompatibility, and was successfully applied to detect Cu2+ and CN- in living cells.


Assuntos
Cobre , Corantes Fluorescentes , Peptídeos , Espectrometria de Fluorescência , Água
10.
J Environ Manage ; 301: 113819, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34592666

RESUMO

Silicon (Si) deficiency and heavy metals (HMs) pollution are common for farmland soil because of long-term intensive farming. In this study, a novel citrate-modified biochar (C-BC) was introduced as a soil conditioner to simultaneously increase the amount of plant-available Si (PASi) and immobilize HMs. The maximum amount of PASi released was 33.00 mg⋅g-1 from C-BC pre-treated with 0.1 mol⋅L-1 citrate (C-BC0.1). A formation-transport coupling mechanism for increasing the amount of PASi released was developed. Stable Si in the biomass was pyrolyzed to give silicate that was relatively mobile via nucleophilic attack of citrate and hydrolysis of amorphous Si. Silicate species were then released through the porous surface and widening cracks caused by pyrolysis. At citrate concentrations >0.1 mol⋅L-1, the surface and cracks were easily blocked by precipitates formed during pyrolysis. The ability of C-BC to remove HMs was assessed using Cu as an example. C-BC0.1 was optimal for adsorbing Cu, and the maximum adsorption capacity was 271.73 mg⋅g-1. The Cu adsorption mechanism mainly involved surface precipitation, surface complexation, electrostatic attraction and hydrogen bonding. Our research provides important implications for simultaneously addressing Si deficiency and HMs contaminant problems by these materials for soil amendment in agro-ecosystem.


Assuntos
Cobre , Silício , Adsorção , Carvão Vegetal , Ácido Cítrico , Ecossistema
11.
J Environ Manage ; 301: 113888, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619584

RESUMO

In this study, chelating surfactant N-lauroyl ethylenediamine triacetate (N-LED3A) was used as strengthening agent for electrokinetic (EK) remediation of copper (Cu) and decabromodiphenyl ether (BDE209) co-contaminated low permeability soil. The results indicated that negligible amount of N-LED3A would be adsorbed on the experimental soil. The synchronous elution efficiencies (SEEs) of Cu and BDE209 had reached 65.4% and 49.9%, respectively, when the concentration of N-LED3A was 4000 mg/L, and they kept almost unchanged as the concentration of N-LED3A further increased. Meanwhile, the optimal SEEs were obtained at the pH condition within 6-8. The removal efficiencies of Cu (55.3%-65.8%) and BDE209 (31.4%-46.4%) would be increased with the applied voltage gradient and concentration of N-LED3A. In addition, BDE209 and Cu contaminants were also detected in the catholyte and anolyte, respectively, and their concentrations still showed an uptrend by the end of the experiments. While in the control experiments, the removal efficiency of Cu was in the range of 18.2%-23.6%, and almost no BDE209 was migrated out. The electric current would be increased with N-LED3A concentration increased, further resulting in the enhancement of cumulative electro-osmotic flow (EOF). However, the increment of EOF was limited after an 8-day treatment due to the declined capacity of the soil water supply, and the removal efficiency of BDE209 did not change proportionally to the cumulative EOF as a consequence. The accumulated (21 days) energy consumption under the optimal operation conditions (voltage gradient 1 V/cm, N-LED3A 1 g/L) was 377.28 KWh/m3. Efficiently synchronous removal of BDE209 and Cu could be achieved by the N-LED3A enhanced EK technique, exhibiting a promising application potential in the organic pollutant and heavy metal co-contaminated soil remediation.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Cobre/análise , Etilenodiaminas , Éteres Difenil Halogenados , Permeabilidade , Solo , Poluentes do Solo/análise , Tensoativos
12.
J Environ Manage ; 301: 113895, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634724

RESUMO

Copper leached from recreational vessel antifouling paints can pose a threat to aquatic organisms. To date, leaching rates have mainly been studied in seawater and brackish water. The aim of this study was to investigate the copper input from antifouling paints to freshwater using field and laboratory studies. Therefore, a large sailing area in Berlin was sampled. According to a risk assessment, the use of copper containing antifouling paints in Berlins is predicted to have no significant impact on aquatic organisms. An exception was found in sport boat marinas where, in dependence on the boat number, the sediment copper concentrations were up to 2 times higher than the German environmental quality standard for sediments. The most important result revealed by the laboratory batch tests is that the copper leaching rate in freshwater is much lower compared to seawater and brackish water. The dissolution of copper from antifouling paints into freshwater is overestimated up to now. Nevertheless, the leached copper from antifouling paints is the second largest anthropogenic copper source in the urban area of Berlin and the third largest anthropogenic copper source in German freshwaters.


Assuntos
Incrustação Biológica , Poluentes Químicos da Água , Berlim , Incrustação Biológica/prevenção & controle , Cobre/análise , Água Doce , Pintura , Poluentes Químicos da Água/análise
13.
Food Chem ; 367: 130659, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343800

RESUMO

This study presents a sensitive approach for electrochemical determination of 5-hydroxymethylfurfural (5-HMF) in food. The electrochemical sensor was fabricated on a copper electrode (CuE) modified with co-electrodeposited Cu-Ni bimetallic particles. This sensor, fabricated by 30 cycles of cyclic voltametric scanning with a scan rate of 50 mV s-1, exhibits good electrocatalytic ability to 5-HMF oxidation. Under the optimal conditions, linear scan voltammetry (LSV) and chronoamperometry were conducted for the determination of 5-HMF. The results of LSV show that a linear dependency within the 0.4-10 mM range with a detection limit (LOD) of 3.51 µM (S/N = 3) was achieved, while a linear range in 1 × 10-4-11 mM with a LOD of 0.043 µM (S/N = 3) was obtained by chronoamperometric measurement. The electrochemical sensor was finally applied in determination of 5-HMF in various foods, and the reliability and accuracy of the method were assessed by adopting an UV method as a standard method. Results show that the concentrations of 5-HMF in real samples are close to those measured by the standard method. In addition, standard addition method was further performed to evaluate the accuracy of our approach. The recoveries ranged from 90.0% to 110.0% are calculated, demonstrating good accuracy of the electrochemical sensor.


Assuntos
Cobre , Técnicas Eletroquímicas , Eletrodos , Furaldeído/análogos & derivados , Limite de Detecção , Reprodutibilidade dos Testes
14.
Food Chem ; 367: 130669, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34365252

RESUMO

Analysis of digital images by smartphone was used for copper quantification in sugarcane spirit (cachaça) samples through the formation of blue complex between copper and cuprizone. An experimental design was carried out to evaluate the best complexation reaction conditions. Moreover, different image acquisition procedures (external camera coupled to a smartphone or the smartphone camera) with different regions of interest sizes, distances in image acquisition, and concentration ranges of the calibration curve and the influence of processing the curve in univariate and multivariate modes, by PLS, were evaluated. The results obtained in three real samples and two spikes were compared with those of UV-Vis spectrophotometry, used as a reference method, and they show the potential of the proposed method for the accurate determination of copper. When compared to traditional techniques, the proposed method has the advantages of portability and low cost in addition to requiring a smaller amount of reagents.


Assuntos
Cobre , Saccharum , Grão Comestível , Projetos de Pesquisa , Smartphone
15.
Food Chem ; 367: 130748, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34375894

RESUMO

The development of a collaborative study as a requirement for the preparation of a laboratory reference material candidate is reported in this paper. The evaluation was performed by 13 laboratories invited to quantify the calcium, potassium, magnesium, phosphorus, copper, iron, manganese and zinc; 8 of them presented results for all the analytes under investigation. The data were statistically analyzed by applying the z-score robust technique as recommended by ISO Guide 35. For the potassium element, laboratories 4 and 13 presented questionable results. Laboratory 5 proved to be unsatisfactory for calcium and zinc. ANOVA-PCA and DD-SIMCA were also applied to evaluate stability and interlaboratory studies results, respectively. It has been demonstrated that multivariate data analysis can be successfully applied as an alternative method to the recommendations made by ISO 13528 and ISO Guide 35 with defined confidence intervals.


Assuntos
Laboratórios , Zea mays , Análise de Variância , Cálcio , Cobre , Farinha , Magnésio
16.
Sci Total Environ ; 803: 150001, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34492493

RESUMO

Copper oxide nanoparticles (CuO-NPs) have been increasingly released in aquatic ecosystems over the past decades as they are used in many applications. Cu toxicity to different organisms has already been highlighted in the literature, however toxicity mechanisms of the nanoparticulate form remain unclear. Here, we investigated the effect, transfer and localization of CuO-NPs compared to Cu salt on the aquatic plant Myriophyllum spicatum, an ecotoxicological model species with a pivotal role in freshwater ecosystems, to establish a clear mode of action. Plants were exposed to 0.5 mg/L Cu salt, 5 and 70 mg/L CuO-NPs during 96 h and 10 days. Several morphological and physiological endpoints were measured. Cu salt was found more toxic than CuO-NPs to plants based on all the measured endpoints despite a similar internal Cu concentration demonstrated via Cu mapping by micro particle-induced X-ray emission (µPIXE) coupled to Rutherford backscattering spectroscopy (RBS). Biomacromolecule composition investigated by FTIR converged between 70 mg/L CuO-NPs and Cu salt treatments after 10 days. This demonstrates that the difference of toxicity comes from a sudden massive Cu2+ addition from Cu salt similar to an acute exposure, versus a progressive leaching of Cu2+ from CuO-NPs representing a chronic exposure. Understanding NP toxicity mechanisms can help in the future conception of safer by design NPs and thus diminishing their impact on both the environment and humans.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Poluentes Químicos da Água , Cobre/análise , Cobre/toxicidade , Ecossistema , Humanos , Nanopartículas Metálicas/toxicidade , Óxidos , Análise Espectral , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
17.
Sci Total Environ ; 803: 150084, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500274

RESUMO

Currently, the environmental and ecological damage caused by As(V) and Sb(V) co-contamination has attracted widespread attention worldwide. Due to the similar intrinsic structure configuration and electrostatic repulsion of As(V) and Sb(V), the long-standing issue of their low co-removal capacity remains unresolved. In this study, novel Fe-Cu (FC) binary materials with varied Fe/Cu proportions were synthesized via a simple co-precipitation method to co-eliminate aquatic As(V) and Sb(V). A 2/1 ratio of Fe/Cu was determined to be a suitable proportion with a higher co-adsorption capacity, specifically 70.9 mg·g-1 for As(V) and 94.3 mg·g-1 for Sb(V). Detailed morphological and structural analyses indicated that the FC material gradually changed from microscale aggregates to nanoscale spheres with increasing Cu content, accompanied by an increasing crystalline degree and higher surface area. Additionally, the transformation of amorphous ferrihydrite (FO) into FeO(OH) was suppressed by Fe-Cu complexion during the co-adsorption process, in which ferrihydrite (FO) had more adsorption sites than FeO(OH). In addition, the addition of Cu promoted the pHpzc of FC materials from the acidic range into the neutral or alkaline range. The increased potential difference of FC materials accelerated the As(V) and Sb(V) diffusion rate and effectively offset native electrostatic repulsion, which exhibited a considerable effect than the adsorption sites. Through detailed kinetic data analysis, it was determined that the proportion of the diffusion layer thickness around Sb(V) was suppressed to the As(V) level, and the adsorption kinetics of the two species were both promoted by the self-driven force field. All the results indicated that the co-adsorption capacity depended on the coupling contribution of Fe and Cu, where Fe oxide acted as the major adsorption potential and Cu provided a self-driven force for As(V) and Sb(V) diffusion. This study may provide a novel prospective for homogeneous metal ion co-removal.


Assuntos
Óxidos , Poluentes Químicos da Água , Adsorção , Antimônio , Cobre , Concentração de Íons de Hidrogênio , Estudos Prospectivos , Água
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120313, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34474223

RESUMO

Copper ion (Cu2+) is an essential part of the living organisms. Cu2+ ions play a vital role in many biotic processes. An abnormal amount of Cu2+ ions may result in serious diseases. Herein, a novel "fluorescent ON" probe NC-Cu to trace minute levels of Cu2+ ions in presence of various biological active species has been developed. Lysosomal cells targeting group (Morpholine) was added to the probe. The spectral properties of probe NC-Cu were recorded in HEPES buffer (0.01 M, pH = 7.4, comprising 50% CH3CN, λex = 430 nm, slit: 5 nm). The synthesized probe NC-Cu work based on copper promoted catalytic hydrolysis of hydrazone and shows remarkable fluorescence enhancement. The reaction of the probe with Cu2+ ions was completed within 20 min. An excellent linear relationship (R2 = 0.9952) was found and the limit of detection (LOD, according to the 3σ/slope) for Cu2+ ions was calculated to be 5.8 µM. Furthermore, NC-Cu was effectively functional in the living cells (KYSE30 cells) to trace Cu2+ ions.


Assuntos
Cumarínicos , Corantes Fluorescentes , Cobre , Íons , Espectrometria de Fluorescência
19.
Food Chem ; 369: 130964, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479006

RESUMO

Based on the electrostatic interaction, we constructed a ratiometric fluorescence nanomixture of graphene quantum dots-gold nanoclusters (GQDs-AuNCs) for the quantitative detection of Cu2+ and Cd2+. When Cu2+ or Cd2+ was added into the reaction system, the fluorescence of GSH-AuNCs at 565 nm can be quenched by Cu2+ and enhanced by Cd2+ while the intensity of N-GQDs at 403 nm stayed constant. Under the optimized conditions, the fluorescence intensity ratio (I565/I403) of the GQDs-AuNCs system was proportional to the concentration of Cu2+ and Cd2+ in the range of 8×10-8 mol/L-6×10-6 mol/L and 1×10-6 mol/L-4×10-5 mol/L, respectively, with detection limits of 4.12×10-9 mol/L and 9.43×10-7 mol/L, respectively. In the presence of Cu2+ and Cd2+, the paper-based vision sensor would produce visible fluorescent color changes, which can be used for rapid detection on site. The method has been successfully applied to the determination of Cu2+ and Cd2+ in scallops with satisfactory results.


Assuntos
Grafite , Nanopartículas Metálicas , Pectinidae , Pontos Quânticos , Animais , Cádmio , Cobre , Corantes Fluorescentes , Ouro , Íons , Nitrogênio , Espectrometria de Fluorescência
20.
J Colloid Interface Sci ; 606(Pt 1): 898-911, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34481249

RESUMO

Developing photocatalysts that are inexpensive and efficient in degrading pollutants are essential for environmental remediation. Herein, a novel system of perylene diimide (PDI)/CuS p-n heterojunction was synthesized by a two-step self-assembly strategy for removal of tetracycline in waste water. Results showed that PDI/CuS-10% exhibited highest photocatalytic behavior. The apparent rate constants for tetracycline (TC) degradation for the blend were 5.27 and 2.68 times higher than that of CuS or PDI, respectively. The enhancement of photocatalytic activity was mainly attributed to the π-π stacking and p-n junction, which can accelerate the separation of the photo-generated h+-e- pairs. Besides, the light absorption of PDI/CuS from 800 to 200 nm was significantly enhanced and the absorption edge even reached the near-infrared region, which also played an important role in providing desired photocatalytic properties. Surprisingly, PDI/CuS could maintain high catalytic activity even after 5 cycles under simulated conditions, indicating that the composite had high potential for practical applications. Owing to high efficiency, low cost and wide application range, the PDI/CuS nanocomposites are promising candidates for environmental remediation.


Assuntos
Recuperação e Remediação Ambiental , Perileno , Cobre , Luz
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