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1.
Anal Chim Acta ; 1191: 339361, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033238

RESUMO

A method for highly sensitive determination of trace antimony was proposed by using cobalt ion enhanced photochemical vapor generation (PCVG) for sample introduction into atomic fluorescence spectrometry (AFS) or inductively coupled plasma-mass spectrometry (ICP-MS) for elemental detection. During the PCVG process, the sample introduction efficiency of Sb could be significantly improved by addition of 5 mg L-1 Co2+ in the mixed acid medium of 10% (v/v) formic acid and 20% (v/v) acetic acid, with a final 12-fold and 133-fold enhancement of AFS and ICP-MS intensity, respectively. The experimental conditions including enhancement ions, acid medium, UV irradiation, working gas as well as potential interference were investigated in detail. Under the optimal experimental conditions, the limit of detection (LOD) for Sb was 0.05 and 0.001 µg L-1 by using AFS and ICP-MS determination, respectively. The method was successfully used for analysis of real water samples, with satisfactory recoveries of 92-94%.


Assuntos
Antimônio , Cobalto , Íons , Espectrometria de Fluorescência , Água
2.
Anal Chim Acta ; 1191: 339209, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033241

RESUMO

Acupuncture needles are regarded as ideal materiel for the development of microelectrodes for in vivo sensing. In this work, an all-solid-state ion-selective microelectrode (ISµE) has been developed by coating a calcium ion-selective membrane on an acupuncture needle tip with a diameter of less than 80 µm, which is modified with poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) as solid contact. The proposed Ca2+-ISµE shows a Nernstian response toward Ca2+ in the range from 1.0 × 10-6 to 3.1 × 10-3 M with a slope of 30.8 ± 0.9 mV/decade (R2 = 0.999), and the detection limit is 1.2 × 10-7 M. The Ca2+-ISµE has been used for in vivo monitoring of the calcium changes in rat cerebrospinal fluid (CSF) under the injury of spinal cord transection. The results demonstrate that the calcium concentration in CSF increases sharply from the normal level of 20.6 ± 1.72 µM (n = 3) to 133.2 ± 7.63 µM (n = 3) with a severe fluctuation after spinal cord damage. Thus, the proposed Ca2+-ISµE is available for in vivo monitoring of calcium ions with high temporal resolution and flexibility. The detection system can be extended to measure other ions in CSF by changing different ion-selective membranes.


Assuntos
Terapia por Acupuntura , Cálcio , Animais , Íons , Microeletrodos , Agulhas , Ratos
3.
Anal Chim Acta ; 1191: 339311, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033242

RESUMO

Compared to water-soluble carbon dots (CDs) the properties and applications of hydrophobic CDs are rarely addressed. In this study, a one-pot, simple chemical oxidation approach has been applied to synthesize hydrophobic carbon dots (TO-CDs) at room temperature from triolein (TO) in concentrated sulfuric acid solution. Sodium copper chlorophyllin (SCC) quenches the fluorescence of TO-CDs by a photoinduced electron transfer process. Upon excitation at 400 nm, the fluorescence intensity of TO-CDs probe at 500 nm shows a linear response against the SCC concentration ranging from 1.0 to 10 µM, with a limit of detection (LOD) of 0.61 µM. Quantitation of SCC in flavored drinks shows percentage recovery (%R) vaues of 98-103% and relative standard deviation (RSD) values less than 6.5%. The hydrophobic TO-CDs can be converted into hydrophilic TO-CDs through hydrolysis in NaOH solution. The presence of sulfonyl groups on the hydrophilic TO-CDs enhances the coordination ability of the CDs toward Cu2+ ions, leading to fluorescence quenching which allows for the detection of Cu2+ ions with LOD of 0.21 µM and a linear range of 0.5-10 µM. The hydrophilic TO-CD probe possesses high selectivity toward Cu2+ ions (tolerance at least ten-fold comparative to other metal ions). The assay has been validated with the analysis of spiked soil samples, with %R values of Cu concentration of 97.8-99.0% and RSDs below 2.0%. The surface tunable CD probes demonstrate their potential for the rapid screening of Cu2+ ions in environmental samples and SCC in foods.


Assuntos
Carbono , Pontos Quânticos , Clorofilídeos , Cobre , Corantes Fluorescentes , Íons , Espectrometria de Fluorescência
4.
Anal Chim Acta ; 1191: 339251, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033275

RESUMO

Owing to the high risk to human and environmental health, heavy metal pollution has become a global problem. Rapid, accurate and multiplexed determination of heavy metal ions is critical. In this work, we reported a promising approach to designing ratiometric fluorescent nanoprobes for multiplexed determination of Hg2+, Cu2+, and Ag+ ions. The nanoprobes (CDs-QDx) were designed by mixing the CDs and multicolor CdTe QDs without the involvement of recognition elements. The CDs were insensitive to heavy metal ions while CdTe QDs showed the size-dependent fluorescence response to different heavy metal ions, thereby establishing a ratiometric detection scheme by measuring the fluorescence intensity ratios of CDs-QDx systems. By evaluating the detection performance, the CDs-QDx (x = 570, 650, and 702) were successfully used for differentiation and quantification of Hg2+, Cu2+, and Ag+ ions. In addition, we also carried out the detection of heavy metal ions in actual samples with acceptable results. We believed that this work offers new insight into the design of ratiometric fluorescent nanoprobe for multiplexed determination of not only heavy metals but also some other analytes by combining the CDs with CdTe QDs with fine-tuned sizes.


Assuntos
Compostos de Cádmio , Metais Pesados , Pontos Quânticos , Carbono , Humanos , Íons , Telúrio
5.
Anal Chim Acta ; 1191: 339297, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033277

RESUMO

Hydrophilic interaction liquid chromatography (HILIC) coupled to drift tube ion mobility spectrometry (DTIMS) was used to separate diastereomers of five-unit oligonucleotides containing 0, 1, 2 or 3 phosphorothioate (PS) linkages. Multiplexed DTIMS (where ions are pulsed into the drift tube according to a pre-encoded sequence) and post-acquisition processing using an innovative demultiplexing tool were investigated. The electric field inside the drift tube was optimized to achieve the highest resolving power. The entrance voltage providing the best two-peak resolution was -1000V with 3-bit multiplexing. Under optimized conditions, the eight diastereomers of an oligonucleotide with three PS linkages (5'-TC∗G∗T∗G-3') could be separated unambiguously. Indeed, those diastereomers differed in their collision cross section (CCS) values. The minimal CCS values difference between two adjacent diastereomers was 0.9% with maximal RSD on CCS values of 0.3%. The use of multiplexed ion mobility and the novel high-resolution demultiplexing tool represents a real breakthrough for resolution enhancement of diastereomers in linear DTIMS.


Assuntos
Espectrometria de Mobilidade Iônica , Oligonucleotídeos , Cromatografia Líquida , Íons , Espectrometria de Massas
6.
Se Pu ; 40(1): 74-81, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-34985218

RESUMO

Adsorbable organic halogens (AOX) are often introduced or produced in textile and dyeing processes, such as the chlorination shrink proof process of wool, the bleaching process by sodium hypochlorite and chlorite, the dry-cleaning process by chlorinated solvent, etc. However, part of AOX is difficult to biodegrade and is a persistent bioaccumulative toxic substance with high fat solubility. To promote clean production of textiles and to protect the health of consumers, a conventional method for the detection of AOX in textiles must be established urgently. In this study, a new method was developed for the determination of AOX in textiles by ultrasonic extraction-high temperature combustion absorption-ion chromatography (IC). In this method, AOX in textiles were extracted by ultrasonic extraction at room temperature with ultra-pure water as solvent. Activated carbon was added to the extraction solution for oscillatory adsorption and removal of inorganic halides with acidic sodium nitrate solution. The AOX adsorbed on activated carbon were cracked, burned, and gasified by the oxidative combustion method with a programmed heating mode. The product hydrogen halide gas entered the absorption solution with the carrier gas, followed by separation and determination by IC with external standard method of quantification. During the experiment, the pretreatment conditions were optimized, including the extraction time of AOX, the amount of activated carbon, the combustion gas and its flow rate, the temperature program for high-temperature oxidation combustion, the absorption method, and the absorption solution. The instrument conditions of ion chromatography, including the chromatographic column, column temperature, eluent, and its flow rate, were also optimized. The results showed that the method was linear in the range of 0.02-10 mg/L for the standard solutions of fluorine, chlorine, bromine, and iodine ions, and the correlation coefficients (R2) were greater than 0.999. The limits of quantification of the method for AOX were 0.10-0.50 mg/kg. The negative textile samples of cotton, wool, and polyester were used as the sample matrix, and typical organic halogens were selected for standard addition and recovery. At low, medium, and high spiked levels, the average recoveries of AOX in cotton, wool, and polyester fiber were 82.3%-98.7%. The corresponding relative standard deviations (RSDs, n=7) were 2.0%-5.7%, indicating that the method had good recovery and precision. This method was used to determine actual textile samples, and AOX at different contents were detected in blue coated polyester fabric and black modal fabric with good repeatability. The established method improved the recoveries of AOX converted into inorganic halogens via oscillating adsorption of activated carbon, high-temperature oxidation combustion with a programmed heating mode, and secondary absorption using a porous absorption bottle. Meanwhile, the separation and detection of halogen ions was successfully conducted using the ion chromatography instrument with good selectivity and high sensitivity, without any interference of impurity ions. The method is simple, accurate, and reliable, and fully meets the limit requirements of domestic and foreign regulations and textile standards; the method is also suitable for the detection and analysis of AOX in textiles.


Assuntos
Halogênios , Ultrassom , Animais , Cromatografia , Íons , Temperatura , Têxteis
7.
Se Pu ; 40(1): 82-87, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-34985219

RESUMO

Water-soluble ions are important components of solid and liquid aerosols. The ions have a significant impact on the physical and chemical properties of the aerosols and air quality. Thus, determining the concentrations of water-soluble ions in solid and liquid aerosols has far-reaching significance for mitigating pollution and protecting the atmospheric environment. In this study, a technology combining membrane filtration, condensation, and ion chromatography has been established to collect solid aerosols and liquid aerosols and to measure the amount of five water-soluble anions (Cl-, F-, NO3-, NO2-, and SO42-) in these aerosols. First, a solid particle filter was used to collect the solid aerosol, and the condensation collection method was used to collect the liquid aerosol. The solid aerosol was collected in the solid particle filter in the form of solid particles, and the liquid aerosol was collected in the cold trap in the form of a condensate. Next, the amount of water-soluble anions in the solid aerosols and liquid aerosols was detected by ion chromatography using Dionex IonPac AS11-HC-4 µm as the analytical column. The chromatographic separation conditions were as follows: flow rate, 1 mL/min; column temperature, 30 ℃; potassium hydroxide (KOH) concentration of the eluent, 1 to 25 mol/L (linear increase) within 0-40 min; and injection volume, 100 µL. The ions were separated effectively within 40 min. The five anions showed good linear relationships in the range of 0.1-10 mg/L (correlation coefficients ranged from 0.9992 to 0.9997) and the detection limits were 0.02-0.04 mg/L. Finally, the sample collection conditions (sampling time, sampling temperature, and sampling flow rate) for the five water-soluble anions in the solid aerosols and liquid aerosols were optimized, and 2 h, -13 ℃, 1.0 L/min were chosen.Under the optimized conditions, the amounts of the five anions in the solid and liquid aerosols of the actual samples were detected. The mass concentrations of F-, Cl-, NO2-, NO3-, and SO42- ions in the liquid aerosol of the actual sample were 5.7402 µg/m3, 1.1599 µg/m3, 3.3233 µg/m3, 2.4861 µg/m3, and 0.9745 µg/m3, respectively. The mass concentrations of F-, Cl-, NO2-, NO3-, and SO42- ions in the solid aerosol of the actual sample were 14.1037 µg/m3, 5.0398 µg/m3, 9.3052 µg/m3, 8.4528 µg/m3, and 5.6314 µg/m3, respectively. The method can be applied to the detection of actual atmospheric ions detection. In addition, the collection and analysis methods are suitable for exploring the collection and analysis conditions of other ions.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Ânions , Cromatografia , Monitoramento Ambiental , Íons/análise , Água
8.
Food Chem ; 375: 131823, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34920305

RESUMO

Suppressing toxic aldehydic lipid oxidation product (LOP) generation in culinary oils is now considered vital, since the deleterious effects arising from their ingestion are implicated in a wide range of disease conditions. Partial substitution involves the replenishment of thermally-stressed culinary oils with corresponding unheated ones. This technique was tested by employing 10%, 25%, 50%, and 75% (v/v) partial substitutions of coconut, olive, rapeseed, and sunflower oils at 180℃ for a 300 min continuous thermo-oxidation duration. Oil samples were analysed by proton nuclear magnetic resonance (1H NMR) spectroscopy. Trace metal levels, including oxidation-reduction (redox)-active metal ions credited with enhancing cooking oil oxidation were also analysed using inductively coupled plasma-optical emission spectroscopy (ICP-OES). As expected, the degree of oil unsaturation, and the % partial substitutions significantly influenced their susceptibility to thermo-oxidation. In view of the very low polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) contents of coconut oil, both the class and concentrations of evolved LOPs were found to be least affected by this partial substitution process. Aldehydic LOPs were greatly suppressed in partially-substituted rapeseed oil. The % suppression activity of LOPs evaluated for the partially substituted oils were generally high making partial oil substitutions an effective chemical-free method in suppressing LOPs at both industrial and commercial levels. In general, the % partial oil substitutions were directly related to the dilution effect observed for LOPs quantified in the oils. Furthermore, trace metal ion concentrations measured in the culinary oils did not influence the evolution of LOPs in the oils.


Assuntos
Gorduras Insaturadas na Dieta , Óleos , Íons , Peroxidação de Lipídeos , Azeite de Oliva , Oxirredução , Óleos Vegetais , Óleo de Girassol
9.
Food Chem ; 375: 131858, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34923397

RESUMO

The paper provides a comprehensive survey of the use of capillary and microchip electrophoresis in combination with contactless conductivity detection (C4D) for the analysis of drinking water, beverages and foodstuffs. The introduction sets forth the fundamentals of conductivity detection anddescribes an axialC4Dversion. There is also a detailed discussion of the determination of inorganic ions, organic acids, fatty acids, amino acids, amines, carbohydrates, foreign substances and poisons from the standpoint of separation conditions, sample treatment and detection limits. Special attention is paid to the analysis of foodstuffs at microchips with emphasis on the employed material and connection of the microchip with the C4D. The review attempts to draw attention to modern trends, such as dual-opposite injection, field-enhanced sample injection, electromembrane extraction and on-line combination of microdialysis with CE. CE/C4D is characterised by high universality, high speed of analysis, simple sample preparation, small consumption of sample and other chemicals.


Assuntos
Eletroforese em Microchip , Bebidas/análise , Condutividade Elétrica , Eletroforese Capilar , Íons
10.
J Chromatogr A ; 1662: 462732, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-34910963

RESUMO

The analysis of mineral oil hydrocarbons in vegetable oils is challenging especially regarding the analysis of mineral oil aromatic hydrocarbons (MOAH) since native terpenes like squalene or ß-carotene are usually extracted along with the MOAH fraction and interfere their detection. When applying a recently developed screening method for the analysis of mineral oil saturated hydrocarbons (MOSH) and MOAH in paper and cardboard by planar solid phase extraction (pSPE) to vegetable oils, native terpenes expectably interfered with MOAH analysis. Thus, an adaption of pSPE employing silver ions, named silver ion-planar solid phase extraction (Ag-pSPE), was developed in this study. Impregnation of thin-layers with silver nitrate (AgNO3) was found to be very successful in retaining squalene and ß-carotene. MOAH analysis of vegetable oils after saponification showed good repeatability (relative standard deviation (%RSD) <10%) and recoveries of 73.4-112.4% at a spiking level of 4.5 mg/kg (n = 4). For MOSH analysis, a simple solid phase extraction (SPE) clean-up with aluminum oxide removed native n-alkanes prior to Ag-pSPE. Recoveries for MOSH were 55.3-84.5% with %RSD <11% at a spiking level of 45.5 mg/kg (n = 4). Limits of decision and quantitation were at 7.2 and 22.2 ng/zone for MOSH and 1.1 and 3.4 ng/zone for MOAH, respectively, which corresponded to the recently introduced pSPE method, thus showing that analytes were not affected by the impregnation of HPTLC plates with AgNO3. The method comparison with LC-GC showed similar results for MOSH, while the amounts for MOAH determined by Ag-pSPE were higher.


Assuntos
Óleo Mineral , Óleos Vegetais , Contaminação de Alimentos/análise , Hidrocarbonetos/análise , Íons , Óleo Mineral/análise , Extração em Fase Sólida
11.
Enzyme Microb Technol ; 154: 109962, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34915246

RESUMO

Nanobiohybrid CAL-B/MNPs were synthesized through enzyme in situ reduction of metal ions, including noble and non-noble metals. Lipase CAL-B acted as multifunctional reagents (reducing and supporting agents). The hybrid catalysts were systematically characterized by HRTEM, EDX, MALDI-TOF-MS, and XPS analysis, confirming that highly dispersed 3-5 nm nanoparticles were evenly dispersed on lipase matrix without agglomeration. The mechanism of CAL-B reducing metal ions was investigated, revealing that AGLFFSSKDL in the amino acid sequence of CAL-B from 111 to 128 formed a stable spatial structure through hydrogen bonding, which was the key factor for enzyme in situ reduction of metal ions into highly dispersed nanoparticles.


Assuntos
Lipase , Metais , Catálise , Íons
12.
Plant Physiol Biochem ; 170: 234-248, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34920320

RESUMO

Sesuvium portulacastrum is a true halophyte and shows an optimal development under moderate salinity with large amounts of salt ions in its leaves. However, the specific proteins in response to salt ions are remained unknown. In this study, comparative physiological and proteomic analyses of different leaves subject to NaCl, KCl, NaNO3 and KNO3 were performed. Chlorophyll content was decreased under the above four kinds of salt treatments. Starch and soluble sugar contents changed differently under different salt treatments. A total of 53 differentially accumulated proteins (DAPs) were identified by mass spectrometry. Among them, 13, 25, 26 and 25 DAPs were identified after exposure to KCl, NaCl, KNO3, and NaNO3, respectively. These DAPs belong to 47 unique genes, and 37 of them are involved in protein-protein interactions. These DAPs displayed different expression patterns after treating with different salt ions. Functional annotation revealed they are mainly involved in photosynthesis, carbohydrate and energy metabolism, lipid metabolism, and biosynthesis of secondary metabolites. Genes and proteins showed different expression profiles under different salt treatments. Enzyme activity analysis indicated P-ATPase was induced by KCl, NaCl and NaNO3, V-ATPase was induced by KCl and NaCl, whereas V-PPase activity was significantly increased after application of KNO3, but sharply inhibited by NaCl. These results might deepen our understanding of responsive mechanisms in the leaves of S. portulacastrum upon different salt ions.


Assuntos
Aizoaceae , Plantas Tolerantes a Sal , Íons , Folhas de Planta , Proteômica , Salinidade , Cloreto de Sódio/farmacologia
13.
Chemosphere ; 286(Pt 1): 131572, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34303910

RESUMO

Superparamagnetic nanocomposites integrated with multiple metals, and surface engineered nanoparticles play a vital role in the removal of heavy metals. In the present study, amino-functional silica-coated magnetic nanocomposites with biochar synthesised from Cynodon dactylon plant residues are prepared in a single step reaction process. The synthesised nanocomposites are characterized using various analytical techniques such as FTIR to determine their functional entities, SEM, TEM, EDX and VSM to analyse the size (~50 nm), elements and magnetic nature of the nanocomposites. Characterization reveals that the prepared nanobiochar was coated with silica and a specific amine group. The magnetic saturation value of 50 emu/g confirms the prepared sorbent was superparamagnetic. Kinetics, isotherm and thermodynamics parameters are evaluated to study the metal interaction mechanism with the nanocomposites where the system follows pseudo-second-order kinetics and the four-parameter Fritz Schlunder model for both metal ions. The nanocomposites showed the enhanced adsorption capacity of copper (Cu(II)) ions with 220.4 mg/g and 185.4 mg/g for lead (Pb(II)) ions. The nanocomposites also showed the excessive reusing ability of 15 times with the maximum removal efficiency for Cu(II) and Pb(II) metal ions. Column studies are evaluated to demonstrate the vital performance in the removal of Cu(II) ions and the breakthrough point was inferred for the parameters such as concentration (100-300 mg/L), bed height (1-3 cm) and flow rate (2-4 mL/min). The breakthrough point was attained at 1400 min and the removal efficiency of about 64.58% was obtained.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Adsorção , Cobre , Cynodon , Concentração de Íons de Hidrogênio , Íons , Cinética , Chumbo
14.
J Hazard Mater ; 421: 126657, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315023

RESUMO

The study aims to prepare a novel low-cost and environmentally friendly adsorbent by using date pits (DP) impregnated with cellulose nanocrystals (CNCs) and ionic liquid (IL), named IL-CNC@DP. The batch adsorption of lithium onto IL-CNC@DP and DP were studied at different pH values, initial lithium concentrations, and temperatures. The thermodynamics constants of the adsorption process showed that the IL-CNC@DP was exothermic, did not favor a high level of disorder, and spontaneous in nature. At pH 6, there is a significant increase in the removal efficiency where it increased to 90%. This also could be explained by the fact that electrostatic attraction forces and hydrogen bonding existed between the protonated Li+ and the less protonated IL-CNC@DP adsorbent surface, which enhanced the percentage of Li+ removal. A strong inter- and intra-hydrogen bonding (O-H) stretching absorption is seen at 3311 cm-1 that occurs in cellulose components. In conclusion, the IL-CNC@DP in comparison to the DP confirmed exceptional results proving that the modification enhanced the remediation of the Li+ from water. Furthermore, the selectivity of IL-CNC@DP towards real groundwater samples isolated in Qatar depends upon the physicochemical characteristics of each element.


Assuntos
Água Subterrânea , Líquidos Iônicos , Nanopartículas , Adsorção , Celulose , Íons , Lítio
15.
Chemosphere ; 286(Pt 1): 131654, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34325260

RESUMO

This study reports the thermally assisted solid-state synthesis of a cathode comprising a biowaste-derived nitrogen-doped carbon coating on LiFePO4 (LFP) for Li-ion batteries. The eggshell membrane (ESM), which mainly consists of collagen, is converted into nitrogen-doped carbon with good ionic and electrical conductivity during thermally driven decomposition. The ESM-coated LFP (ESM@LFP) containing pyrrolic nitrogen, pyridinic nitrogen, and oxidized pyridinic nitrogen has been motivated to improve its ionic and electrical conductivity, that promotes the movement of Li-ions and electrons on the LFP surface. ESM@LFP exhibits stable cyclability and ~16.3% of increased specific discharge capacity for 100 cycles at a current rate of 1C compared to bare LFP.


Assuntos
Fontes de Energia Elétrica , Lítio , Carbono , Eletrodos , Íons
16.
J Colloid Interface Sci ; 605: 173-181, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34325339

RESUMO

A rapid, cost-effective and accurate detection of heavy metal ions is crucial for human health monitoring and environmental protection. Surface-enhanced Raman spectroscopy (SERS) has become a reliable method due to its outstanding performance for the identification of contaminants. In this paper, silver phosphate microcubes (Ag3PO4) were fabricated using two different precipitation methods for ultrasensitive SERS detection of heavy metal ions. The use of an organic linker (BPy) with Ag3PO4 enabled the immobilization of Hg2+ and Pb2+ ions. The formation of Ag3PO4 was confirmed by XRD, UV-DRS, FESEM coupled with EDX and HRTEM. The analytical enhancement factor (AEF) obtained was 1010 with a detection limit of 10-15 M indicating high sensitivity. Based on these results, the possible SERS mechanism has been proposed and discussed. Moreover, an excellent reusability of Ag3PO4 substrate for at least four cycles was achieved upon the light exposure on heavy metal loaded substrate due to its superior catalytic ability for the degradation of heavy metal ions. The as-prepared substrate demonstrated remarkable stability, selectivity and SERS sensitivity towards real samples. The results conclude that Ag3PO4 microcubes offer a great prospect in recyclable SERS applications.


Assuntos
Mercúrio , Nanopartículas Metálicas , Humanos , Íons , Fosfatos , Compostos de Prata , Análise Espectral Raman
17.
J Hazard Mater ; 421: 126722, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34332480

RESUMO

The novel sulfomethylated lignin-grafted-polyacrylic acid (SL-g-PAA) hydrogel was fabricated in this work via a facile and green synthetic strategy for the efficient removal of heavy metal ions from wastewater, and then successively reused for chemiluminescence (CL). The sulfomethylation of lignin was first performed to improve its water solubility and introduce numerous active sites for adsorption of heavy metal ions. The as-synthesized SL-g-PAA hydrogel with high content of lignin exhibited the highly efficient and rapid removal of various metal ions from simulated wastewater. More importantly, the spent hydrogel (M2+@SL-g-PAA) after adsorption was reused for the first time to develop a new CL system by an ingenious strategy, in which these metal ions adsorbed on M2+@SL-g-PAA act as heterogeneous catalytic sites to catalyze the CL reaction between N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and H2O2. The resultant CL system displayed high CL intensity and long duration time, which could be observed by naked eye in the dark and lasted for > 24 h. The combination of facile fabrication process, renewable raw materials, and ingenious strategy for successive application in adsorption and CL endows this lignin-based composite hydrogel with a great potential for application in wastewater treatment, biological imaging and cold light sources.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Hidrogéis , Peróxido de Hidrogênio , Íons , Lignina , Luminescência , Águas Residuárias , Poluentes Químicos da Água/análise
18.
J Hazard Mater ; 421: 126728, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34339990

RESUMO

The increasing release of nanomaterials has attracted significant concerns for human and environmental health. Similarly, the dissemination of antimicrobial resistance (AMR) is a global health crisis affecting approximately 700,000 people a year. However, a knowledge gap persists between the spread of AMR and nanomaterials. This study aims to fill this gap by investigating whether and how nanomaterials could directly facilitate the dissemination of AMR through horizontal gene transfer. Our results show that commonly-used nanoparticles (NPs) (Ag, CuO and ZnO NPs) and their ion forms (Ag+, Cu2+ and Zn2+) at realistic concentrations within aquatic environments can significantly promote the transformation of extracellular antibiotic resistance genes in Acinetobacter baylyi ADP1 by a factor of 11.0-folds, which is comparable to the effects of antibiotics. The enhanced transformation by Ag NPs/Ag+ and CuO NPs/Cu2+ was primarily associated with the overproduction of reactive oxygen species and cell membrane damage. ZnO NPs/Zn2+ might increase the natural transformation rate by stimulating the stress response and ATP synthesis. All tested NPs/ions resulted in upregulating the competence and SOS response-associated genes. These findings highlight a new concern that nanomaterials can speed up the spread of AMR, which should not be ignored when assessing the holistic risk of nanomaterials.


Assuntos
Resistência Microbiana a Medicamentos , Íons , Nanopartículas Metálicas , Acinetobacter/genética , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Humanos , Íons/toxicidade , Nanopartículas Metálicas/toxicidade
19.
J Colloid Interface Sci ; 605: 547-555, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34340039

RESUMO

A quasi-solid-state Li-Te battery is developed by using a flexible gel polymer electrolyte (GPE), porous carbon/tellurium cathode, and lithium metal anode. The ionic conductivity of GPE is controllable and reaches up to 8.0 × 10-4 S cm-1 at 25 °C. The good interfacial contact with Li metal ensures excellent cycling stability in Li/GPE/Li symmetric cells. Moreover, it is found that, compared to S and Se counterparts, the Li-Te battery exhibits good rate capability due to the high electrical conductivity of Te and excellent interfacial stability among GPE, Li, and Te. This work provides several facile strategies to develop safe and high-performance solid-state Li-Te batteries.


Assuntos
Lítio , Telúrio , Fontes de Energia Elétrica , Íons , Polímeros
20.
Chemosphere ; 286(Pt 2): 131760, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34352536

RESUMO

Heavy metal ions (HMI) have attracted worldwide concern due to their serious environmental pollution which led to the risk of health conditions. From Red Malus floribunda fruits, nitrogen-doped carbon dots (N-CDs) were prepared, followed by hybrid-spherical shaped hydrogel particles (CGCDs) were prepared. The prepared CGCDs were utilized as adsorbents for HMI-(Hg(II), Cd(II), Pb(II), and Cr(III)) from water. N-CDs with about 4.0 nm in diameter were characterized by various techniques such as field emission-scanning electron microscopy (FE-SEM) and attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) that confirm the presence of nitrogen, oxygen, and carbon functionalities. The prepared spherical CGCDs were characterized very well before it was used as HMI adsorbents. The sizes of the CGCDs were ranges between 20 and 300 µm and the degree of swelling was calculated as 1320 %. ATR-FTIR and X-ray diffraction analyses reveal the presence of N-CDs in CGCDs. Further, FE-SEM confirms the spherical shape morphology of CGCDs. Three different concentrations of HMI solutions were 500 mg/L, 1000 mg/L, and 1500 mg/L. Hg(II) adsorbed proficiently by CGCDs in single metal ion systems with ~72 % and almost complete removal of Hg(II) ions (99 %) in multiple metal ion systems was observed. Moreover, all metal ions Hg(II), Cd(II), Pb(II), and Cr(III) were efficiently (>70 %) removed in multiple systems by CGCDs. After HMI adsorption experiments, the elemental mapping from FE-SEM and X-ray photoelectron spectroscopy studies conveys the presence of HMI on CGCDs. This suggests that CGCDs would be a suitable adsorbent for the simultaneous removal of multiple HMI from wastewater.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Carbono , Hidrogéis , Íons , Metais Pesados/análise , Águas Residuárias , Poluentes Químicos da Água/análise
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