Environmental Water Samples Research Articles

Approach for concurrent detection and removal of diclofenac in wastewater: Integration of MOF with Poly(deep eutectic solvent) imprinting method

Diclofenac in medical wastewater poses a significant threat to the environment and human health. A simple and efficient enrichment strategy has been established for the selective identification and removal for diclofenac in environmental water samples applying MOF based polymeric deep eutectic solvent (Poly(DES)@MOF). Poly(DES)@MOF was synthesized using a surface imprinting method. The components included MOF-199 as the support material, diclofenac as the template, and a deep eutectic solvent (DES) composed of choline chloride and methacrylate (1:2) as the functional monomer. Density functional theory calculated the Gibbs free energy change during the reaction process, confirming that DES improved the binding performance and selectivity of polymer. Related experiments have shown that Poly (DES) @ MOF has high adsorption capacity, reaching equilibrium within 2 h. In real sample experiments, the maximum adsorption capacity of diclofenac in lake water by the extraction device was 19.39 mg·g−1, with an average recovery rate between 99.4 % and 105.8 %. After 5 repeated uses, the performance did not show significant degradation. After evaluating the principles of green analytical chemistry using agree software, the total score was 0.68, reflecting the high greenness of this study. This study combined molecular imprinting technology and computer theory simulation of MOF based and DES mediated polymerization processes to construct an extraction device that was easy to operate and could extract diclofenac from environmental water samples with high selectivity and adsorption capacity. It showed great potential in the field of environmental monitoring and provided a new approach for the detection of other pollutants in the environment.

Fabrication of Cu-BTC@PW12/GO for multivariate sensing dopamine and acetaminophen as electrochemical sensor

Dopamine (DA) and acetaminophen (AP) are closely associated with many physiological and pathological processes, monitoring their levels precisely is of significance in the early diagnosis of diseases. Herein, a polyoxometalate-based metal-organic framework (POMOF) based on phosphotungstate (Cu-BTC@PW12) was immobilized on graphene oxide (GO) to fabricate Cu-BTC@PW12/GO (CPG) as an electrochemical sensor for the quantification of DA and AP. The spatial confinement effect of copper-based MOF (Cu-BTC) remained the catalytic activity phosphotungstate (PW12) avoiding the aggregation, facilitating electro-catalysis performance for detection of DA and AP. The CPG electrochemical sensor achieved the analysis of DA and AP with the limit of detection (LOD) of 24.8 nM and 62.3 nM, respectively. Furthermore, CPG can be applied for the quantification of DA and AP in real human serum and environmental water samples with satisfied recoveries. Therefore, this work expanded the utilization of POMOF in electrochemical analysis and has promising prospects for the early diagnosis of diseases and environmental treatment.

β-cyclodextrin-modulated ratiometric supramolecular BODIPY fluoroprobe for highly selective and sensitive detection of thiophenol

Thiophenol (PhSH) is an important industrial intermediate but displays significant toxicity towards environmental and biological systems. Here, we introduce a supramolecular system based on β-cyclodextrin (β-CD) and boron dipyrromethene (BODIPY) as a ratiometric fluorescence probe to discriminate PhSH in environmental water samples, cells, and in vivo. In aqueous solutions, BODIPY shows extremely weak fluorescence intensity due to its aggregation into nanometer-sized clusters, which prevents its interaction with thiols. However, within a β-CD environment, it can selectively and sensitively detect PhSH. Also, the stability of the probe was significantly improved. The mechanism studies based on stoichiometry, NMR spectroscopy, and theoretical calculation revealed distinct intermolecular interactions between β-CD and BODIPY, including host-guest interactions and hydrogen bonds. Low limit of detection (10.7 nM) and rapid response time (5 min) have been achieved, and the practicality of the supramolecular system (BODIPY@β-CD) has been verified by actual sample analysis. Furthermore, the first hydrogel-based sensing system for portable PhSH detection has been developed, facilitating rapid and on-site colorimetric visualization across both liquid and gas phases. Most importantly, using a low amount of the probe, early stages of low-dose exposure to PhSH can be visualized in living cells and zebrafish. Therefore, BODIPY@β-CD is a robust new monitoring tool for the detection of PhSH in various scenarios, indicating the promising application value of the host-guest supramolecular probe in detecting highly toxic substances.

A multi-dimensional anti-counterfeiting nanocomposite based on fluorescent CDs and Eu-MOFs with dual function for continuous detection of Cu2+ and Bacillus anthracis

Traditional luminescent materials for anti-counterfeiting usually adopt encryption of low-level systems with limited security, which seriously hinders their application in preventing counterfeiting and information leakage. Therefore, it is urgent to develop materials for higher-level anti-counterfeiting. In this work, a stimulus-responsive intelligent luminescent material (AC@CDs-Eu-MOFs) was prepared by co-loading green-fluorescence CDs and red-fluorescence Eu-MOFs on Amino clay (AC). 5D security barcodes, which were easy to observe while difficult to clone, were ulteriorly designed based on the nanocomposite owing to the tunable fluorescence by optical stimulation and chemical stimulus. Owing to the large capacity, low cost, and easy authentication, the 5D security barcodes possess enormous potential in optical data storage and multi-dimensional information encryption. In addition, the chemical stimulus-response enables the nanocomposite achievable in detection of Cu2+ and Bacillus anthracis. Particularly, quantitative determination of copper in environmental water samples could be realized with a detection limit as low as 10.67 nM. Therefore, the material shows potential for detection of environmental pollutants besides advanced anti-counterfeiting.

Ionic Liquid-Solidified Floating Organic Drop Microextraction for the Preconcentration of Lead in Environmental Water Samples Prior to Its Determination with Electrothermal Atomic Absorption Spectrometry.

This research investigates the utilization of an ionic liquid combination of solidified floating organic drop micro-extraction (IL-SFODME) to augment the concentration of trace amounts of lead, working as a preliminary stage before electrothermal atomic absorption spectrometry (ETAAS) analysis without the use of chelating agents. Key parameters impacting the microextraction efficiency-including pH, the volume of the ionic liquid (1-Hexyl-3-methylimidazolium hexafluorophosphate, HMIMPF6), temperature, extraction time, and stirring speed-were methodically examined to determine optimal conditions. Under detected optimized conditions, an enhancement factor of 71.2 was obtained for a 15 mL sample solution. The calibration curve exhibited linearity within the concentration range of 0.2-2.5 µg/L, with a detection limit (3σ) of 0.054 µg/L and a quantification limit (10σ) of 0.18 µg/L. For seven replicate measurements of 0.5 µg/L lead, the relative standard deviation (RSD) was ±2.30%. This method was effectively implemented to extract and quantify lead in both reference water and different real water samples, showcasing significantly efficient extraction performance.

Monomer-mediated growth of β-cyclodextrin-based microporous organic network as stationary phase for capillary electrochromatography.

CD-MONs (β-cyclodextrin-based microporous organic networks), derived from β-cyclodextrin, possess notable hydrophobic characteristics, a considerable specific surface area, and remarkable stability, rendering them highly advantageous in separation science. This research aimed to investigate the utility of CD-MONs in chromatography separation. Through a monomer-mediated technique, we fabricated an innovative CD-MON modified capillary column for application in open-tubular capillary electrochromatography (OT-CEC). The CD-MON-based stationary phase on the capillary's inner surface was analyzed using Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). We assessed the performance of the CD-MON modified capillary column for separation purposes. The microstructure and pronounced hydrophobicity of CD-MON contributed to enhanced selectivity and resolution in separating diverse hydrophobic analytes, such as alkylbenzenes, halogenated benzenes, parabens, and polycyclic aromatic hydrocarbons (PAHs). The maximum column efficiency achieved was 1.5 × 105 N/m. Additionally, the CD-MON modified capillary column demonstrated notably high column capacity, with a methylbenzene mass loading capacity of up to 197.9pmol, surpassing that of previously reported porous-material-based capillaries. Furthermore, this self-constructed column was effectively utilized for PAHs determination in actual environmental water samples, exhibiting spiked recoveries ranging from 93.2 to 107.9% in lake water samples. These findings underscore the potential of CD-MON as an effective stationary phase in separation science.

Rapid and Cost‐Effective Platypus eDNA Detection in Waterways Using Loop‐Mediated Isothermal Amplification Assay: Advancing Conservation Efforts

ABSTRACTFreshwater ecosystems, home to a remarkable diversity of species, are facing severe threats from human activities such as climate change, habitat degradation, over‐extraction of water for irrigation, and pollution. The platypus, an iconic species in freshwater ecosystems around Australia, is threatened by all these activities, both singly and in combination. The scale and complexity of these intersecting and reinforcing threats makes cost‐effective monitoring tools essential to better understand how platypus populations are responding. In this study, we optimized a loop‐mediated isothermal amplification (LAMP) assay for the rapid and cost‐effective detection of platypus DNA in environmental water samples, offering an attractive alternative to quantitative polymerase chain reaction (qPCR). We improved a water filtration protocol for in‐field use, employing suitable filter membranes for processing large volumes of water, thereby maximizing DNA recovery from dilute samples. The limit of detection for the platypus LAMP (Plat‐LAMP) assay was determined to be 12.4 copies/μL using a standard plasmid positive reference and 7 × 10−6 ng/μL when applied to DNA extracted from platypus tissue, with improved sensitivity achieved through the incorporation of locked nucleic acid primers. In comparative testing against qPCR, the Plat‐LAMP assay exhibited greater sensitivity in detecting platypus DNA in known positive water samples collected from platypus habitat at Healesville Sanctuary. Furthermore, the Plat‐LAMP assay demonstrated 100% specificity when performed on water samples collected from non‐platypus habitats. In field testing across waterways in Victoria and New South Wales, the Plat‐LAMP assay detected platypus in 36.96% of samples, compared to 54.35% of samples using qPCR. These findings underscore the Plat‐LAMP assay's potential as a faster and more cost‐effective complementary method to qPCR, rendering it suitable for point‐of‐application water testing. The ability to conduct eDNA surveys without the need for cold‐chain logistics would significantly assist conservation organizations and water managers map platypus distributions and facilitate conservation efforts around Australia.

Design of Selective Nanoparticles of Layered Double Hydroxide (Mg/Al-LDH) for the Analysis of Anti-Inflammatory Non-Steroidal Agents in Environmental Samples, Coupled with Solid-Phase Extraction and Capillary Electrophoresis

A simple, fast, and low-cost pre-concentration methodology based on the application of solid-phase extraction coupled to layered double hydroxides (LDHs) and capillary electrophoresis was developed for the determination of naproxen (NPX), diclofenac (DFC), and ibuprofen (IBP) in environmental sample waters. A systematic study of the LDH composition was designed, including the effects of interlayer anions (NO3−, Cl−, CO32−, BenO−, and SDS−) and the effect of molar ratio (Mg:Al). The optimal composition of MgAl/Cl−-LDH (Mg:Al; 1.5:1.0) was coupled to an SPE system: pH (neutral pH), LDH amount (15 mg), and extraction capacity ranged from 79.71 to 83.11% for the three anti-inflammatory non-steroidal agents analyzed. A recovery rate of up to 80.87% was obtained when 0.01 M chloride acid in methanol was used as the eluent and 50 mL of sample was used. Under optimal conditions, the linear range of the calibration curve ranges from 18.02 to 200 μg L−1, with limits of detection ranging from 6.03 to 18.02 μg L−1 for the three NSAIDs. The precision of the methodology was evaluated in terms of inter- and intra-day repeatability, with %RSD < 10% in all cases. The proposed method was applied to analyze environmental water samples (bottle, tap, cistern, well, and river water samples). The developed method is a robust technique capable of combining with other analytical methods to quantitatively determine anti-inflammatory non-steroidal agents.

Silicon quantum dots based fluorescent probes for detecting methyl parathion pesticide residues in potato, tap water and Yellow River

In this paper, a novel ratiometric fluorescent probe based on silicon quantum dots (SiQDs) has been developed for the sensitive detection of methyl parathion pesticide residues. The silicon quantum dots were prepared by a simple hydrothermal reaction process using 3-Aminopropyltriethoxysilane (APTES) as silicon resource and were characterized by the analysis of transmission electron microscopy, FTIR spectroscopy, and X-ray photoelectron spectroscopy. The silicon quantum dots displayed characteristic blue fluorescence emission at 440 nm. Tyrosinase can catalyze the oxidation of tyramine to form dopamine. Then, dopamine can interact with silicon quantum dots and effectively change the position of its fluorescence emission for redshiftting to 540 nm. In the presence of organic phosphorus pesticides (OPPs), the activity of tyrosinase was inhibited, resulting in the inability to generate dopamine and the fluorescence emission at 440 nm remaining unchanged. As a model of organic phosphorus pesticides, methyl parathion (MP) was determined using this method, and the fluorescence intensity response values showed a good linear relationship with methyl parathion concentration in the range of 50–90 nM, with a detection limit of 0.149 nM. Due to its good performance of relative low detection limit, good selectivity and high reproducibility, this sensing system has been successfully applied to the detection of methyl parathion in environmental water samples and potato samples, which showed good prospects for application in the detection of organic phosphorus pesticide residues in more real samples.

All-Solid-State PVC-Membrane Cu(II)-Selective Potentiometric Microsensor Based on a Novel Calix[4]arene Derivative

In this study, 25,27-dihydroxy-26,28-bis(ethoxycarbonylbutyoxy)-5,11,17,23-p-tert-butylcalix[4]arene was used as an ionophore for the preparation of a novel all-solid-state type microsensor to make a selective potentiometric response towards Cu(II) ions. The optimum membrane composition of the microsensor was determined as 2% (w/w) ionophore, 67% (w/w) bis (2-ethylhexyl) sebacate (DOS), 30% (w/w) polyvinylchloride (PVC), and 1%(w/w) potassium tetrakis 4-chlorophenyl borate (KTpClPB). The Cu(II)-selective microsensor exhibited a highly selective Nernstian response of 31.3±2.1 mV slope (R2: 0.997) with a short response time (15 s) over the concentration range of 10−5 to 10−1 mol L−1 of Cu(II) ions for 8 weeks with no significant difference in potentials. The microsensor was effectively performed in the pH range of 5.0–8.0, with low detection limit as 7.63×10−7 mol L−1, and a temperature range of 15−40 °C. The prepared microsensor was successfully used both as an indicator electrode in the potentiometric titration of Cu(II) ions with EDTA and also in the determination of the Cu(II) content of environmental water samples. When the potentiometric results were compared with ICP-OES, they were found to be in good agreement with ICP-OES results at a 95% confidence level.

Ultrasound assisted upper critical solution temperature type switchable deep eutectic solvent based liquid-liquid microextraction for the determination of triazole in water

BackgroundThe use of pesticides to protect crops has long been an important measure to provide healthy and safe agricultural products, but excess pesticides flow into fields and rivers, causing environmental pollution. Earlier methods utilizing organic solvent liquid-liquid microextraction for pesticide residue detection were not environmentally friendly. Therefore, it is significant to find a greener and more convenient detection method to determine pesticide residues. ResultsA new method was established to detect three triazole fungicides (TFs), including myclobutanil, epoxiconazole and tebuconazole, in environmental water samples. And the determination was conducted using a high-performance liquid chromatography with the ultraviolet detector (HPLC-UV). The switchable deep eutectic solvent (SDES) can be reversibly switched between hydrophilic and hydrophobic states through temperature modulation. Additionally, the method exhibited excellent linearity for all target analytes within the concentration range of 10–2000 μg L−1, with satisfactory R2 values (≥0.9975). The limits of detection (LODs) ranged from 2.3 to 2.6 μg L−1, and the limits of quantification (LOQs) ranged from 7.8 to 8.7 μg L−1. The accuracy of the method was assessed through intra-day and inter-day precision tests, yielding relative standard deviations (RSDs) in the ranges of 2.8%–6.7% and 2.2%–7.5%, respectively. Density functional theory (DFT) results indicated that hydrogen bonding is a significant factor affecting the binding of DES with triazoles. Three different green assessment tools were used to prove that the SDES-HLLME method had good greenness and broad applicability. SignificanceThis is a homogeneous liquid-liquid microextraction (HLLME) method based on the upper critical solution temperature (UCST) type switchable deep eutectic solvent program, which can complete the extraction within a few minutes without dispersant. In terms of pesticide detection, the analytical method is simple and more conducive to environmental protection.

Facile Preparation of Tannic Acid-Gold Nanoparticles for Catalytic and Selective Detection of Mercury(II) and Iron(II) Ions in the Environmental Water Samples and Commercial Iron Supplement.

Tannic acid (TA), a plant-derived polyphenol rich in hydroxyl groups, serves as both a reducing agent and stabilizer for synthesizing gold nanoparticles (TA-AuNPs). This study presents a groundbreaking method that utilizes TA to fabricate TA-AuNPs and develop two distinct colorimetric detection systems for mercury (Hg2+) and iron (Fe2+) ions. The first detection system leverages the interaction between TA-AuNPs and Hg2+ to enhance the peroxidase-like activity of TA-AuNPs, facilitating the production of hydroxyl radicals upon reaction with hydrogen peroxide, which subsequently oxidizes 3,3',5,5'-tetramethylbenzidine (TMB) into a blue-colored product (ox-TMB). The second system capitalizes on TA-AuNPs to catalyze the Fenton reaction between Fe2+ and hydrogen peroxide in the presence of 2, 6-pyridinedicarboxylic acid, boosting the generation of hydroxyl radicals that oxidize TMB into a blue-colored ox-TMB. Absorbance measurements at 650 nm display a linear relationship with Hg2+ concentrations ranging from 0.40 to 0.60 μM (R2 = 0.99) and Fe2+ concentrations from 0.25 to 2.0 μM (R2 = 0.98). The established detection limits for Hg2+ and Fe2+ are 18 nM and 96 nM, respectively. Applications to real-world samples achieved an excellent spiked recovery, spanning 101.6% to 108.0% for Hg2+ and 90.0% to 112.5% for Fe2+, demonstrating the method's superior simplicity, speed, and cost-effectiveness for environmental monitoring of these ions compared to existing techniques.

Ultrasensitive electrochemical sensor based on dimethylglyoxime/carbon paste electrode modified with a bimetallic nanocomposite for nickel detection in environmental water samples

To date, research in the monitoring of heavy metal pollution focuses on developing an advanced and selective sensor. In this study, an electrochemical sensor-based bimetallic nanocomposite modified dimethylglyoxime carbon paste electrode (DMG/CPE) was created to detect Ni2+ selectively. The bimetallic nanocomposite was prepared by depositing a thin layer of silver nanoparticles (AgNPs) on the surface of the magnetite (Fe3O4)/DMG/CPE electrode. The incorporation of Fe3O4 and AgNPs results in a synergistic effect, increasing electron transfer and expanding the electroactive surface area (from 2.78 mm2 to 3.81 mm2), hence leading to an increase in the peak current response (ΔIp = 26.15 ± 0.33 µA at modified CPE). The prepared AgNPs/Fe3O4/DMG/CPE electrode demonstrated excellent properties, allowing for a broad linear dynamic range lying between 2–10 nM; 10–100 nM; and 100–1000 nM and a limit of detection value of 0.6 nM (S/N = 3). Additionally, the developed sensor showed great sensitivity, selectivity, and reliability in the detection of Ni2+ in river water samples, making it promising for a sensitive and selective detection of Ni-contaminated water.

A ratiometric nanoplatform for fluorimetric and visual detection of Cu2+ and biothiols based on Eu MOFs and carbon dots

Herein, a ratiometric nanoplatform was established for fluorimetric and visual detection of Cu2+ and biothiols based on europium-based metal–organic frameworks (Eu MOFs) and carbon dots (CDs). Fluorescent Eu MOFs with red emission was facilely prepared via the coordination of Eu3+ with tetracycline (TC) and 2-[4-(2-hydroxyethyl)piperazin-1-yl] ethanesulfonic acid (Hepes). However, with addition of Cu2+, the fluorescence of Eu MOFs significantly decreased due to higher affinity of Cu2+ with TC, whereas the green fluorescence of CDs was not influenced by Cu2+, which served as an internal standard of the sensing platform. Interestingly, after introducing biothiols, the stronger coordination between Cu2+ and the sulfydryl of biothiols induced the release of TC to coordinate with Eu3+, thus recovering the fluorescence of Eu MOFs. The ratio changes of these two emissions accompanying by the distinct color variations of the solution under a 365 nm ultraviolet lamp could be used as output signals for fluorimetric and visual detection of Cu2+ and biothiols. The nanoplatform exhibited excellent sensing performance with limit detection as low as 0.57 μM for Cu2+, 0.54 μM for glutathione, 0.14 μM for homocyeteine and 0.42 µM for cysteine, respectively. In addition, it was successfully applied to detecting Cu2+ in environment water samples and biothiols in human serum samples, suggesting great potential for Cu2+ and biothiols determination in environmental and biological samples.

Development of a triplex RT-qPCR assay for simultaneous quantification of Japanese encephalitis, Murray Valley encephalitis, and West Nile viruses for environmental surveillance.

The co-circulation of mosquito-borne Japanese encephalitis virus (JEV), Murray Valley encephalitis virus (MVEV), and West Nile virus (WNV) has impacted human and animal health in multiple countries worldwide. To facilitate early warnings and surveillance of the presence of these viral infectious agents in the environment, a triplex reverse transcription-quantitative PCR (RT-qPCR) was developed for simultaneous quantification of JEV, MVEV, and WNV in potential hotspots such as piggery and urban wastewater and environmental water samples. The performance of the developed triplex RT-qPCR assay was compared with that of simplex counterparts, all using the same primer and probe sequences. The quantifiable results showed a concordance rate of 93.9%-100% (Cohen's kappa) between the triplex and simplex assays. The mean concentrations of exogenous JEV, MVEV, and WNV using the triplex and simplex RT-qPCR assays were remarkably similar in piggery/urban wastewater and environmental water samples. However, the impacts of the matrix effects (i.e., sample composition and PCR inhibition) of environmental water samples on the accurate quantification of these viruses need to be considered. Taken together, this newly developed triplex RT-qPCR assay of JEV, MVEV, and WNV will allow for a more rapid and cost-efficient sample analysis and data interpretation. The application of the triplex assay for environmental surveillance may be a valuable tool to complement the existing disease and mosquito surveillance approaches used to safeguard the health of both humans and animals.IMPORTANCEThe co-circulation of mosquito-borne Japanese encephalitis virus (JEV), Murray Valley encephalitis virus (MVEV), and West Nile virus (WNV) poses significant threats to human and animal health globally. In this study, a triplex RT-qPCR assay was developed for simultaneous quantification of these viruses in wastewater and environmental water samples. Results demonstrated high concordance and sensitivity of the newly developed triplex RT-qPCR assay compared to simplex assays, indicating its efficacy for environmental surveillance. This cost-effective and rapid assay offers a vital tool for timely monitoring of mosquito-borne viruses in environmental samples, enhancing our ability to mitigate potential outbreaks and safeguard public health.

Pathways of exposure to Vibrio Cholerae in an urban informal settlement in Nairobi, Kenya.

Cholera is a diarrhoeal disease caused by Vibrio cholerae (V. cholerae) bacterium, with strains belonging to serogroups 01 and 0139 causing a huge proportion of the disease. V. cholerae can contaminate drinking water sources and food through poor sanitation and hygiene. This study aimed to identify environmental routes of exposure to V. cholerae within Mukuru informal settlement in Nairobi. We collected nine types of environmental samples (drinking water, flood water, open drains, surface water, shaved ice, raw produce, street food, soil, and public latrine swabs) over 12 months. All samples were analysed for V. cholerae by culture and qPCR, then qPCR-positive samples were quantified using a V. cholerae DNA standard. Data about the frequency of contact with the environment was collected using behavioural surveys. Of the 803 samples collected, 28.5% were positive for V. cholerae by qPCR. However, none were positive for V. cholerae by culture. V. cholerae genes were detected in majority of the environmental water samples (79.3%), including open drains, flood water, and surface water, but were only detected in small proportions of other sample types. Vibrio-positive environmental water samples had higher mean V. cholerae concentrations [2490-3469 genome copies (gc) per millilitre (mL)] compared to drinking water samples (25.6 gc/mL). Combined with the behavioural data, exposure assessment showed that contact with surface water had the highest contribution to the total V. cholerae exposure among children while ingestion of municipal drinking water and street food and contact with surface water made substantial contributions to the total V. cholerae exposure for adults. Detection of V. cholerae in street food and drinking water indicates possible risk of exposure to toxigenic V. cholerae in this community. Exposure to V. cholerae through multiple pathways highlights the need to improve water and sanitation infrastructure, strengthen food hygiene practices, and roll out cholera vaccination.

Superhydrophobic Metal-Organic Framework-Based Composite Featuring Removal of Hydrophobic Drugs and Pesticides and Antibacterial Activities.

The widespread use and contamination of natural sources by new-generation drugs and pesticides have enhanced concern about environmental pollution. Understanding the above importance, we developed a superhydrophobic metal-organic framework (MOF) (SHMOF': [Zr6O4(OH)4(BDC-NH-CO-R)2.4(BDC-NH2)0.6(CF3COO)6]·2.5H2O·4DMF) for ecological remediation via adsorption-based separation of hydrophobic drugs (flurbiprofen) and pesticides (fluazinam). The newly developed SHMOF' has a high adsorption capacity toward flurbiprofen and fluazinam, i.e., 435 and 575 mg/g, respectively. The adsorption equilibrium time of the MOF is very short (15 and 10 min for flurbiprofen and fluazinam, respectively). The outstanding superhydrophobic nature of the MOF was employed to separate flurbiprofen and fluazinam from highly alkaline and acidic media and environmental water samples. The SHMOF' has excellent selectivity toward the adsorption-based separation of flurbiprofen and fluazinam in the coexistence of common analytes. Again, we developed a polypropylene (PP) fabric-based composite of SHMOF' (SHMOF'@PP) to separate the hydrophobic targeted analytes by using a zero-energy-consuming filtration-based separation method, which made this separation process cost-efficient and user-friendly. Moreover, Ag nanoparticles were doped to the superhydrophobic composite. The Ag-doped reusable SHMOF'@PP@Ag composite exhibited excellent bacterial antiadhesion and antibacterial properties toward Staphylococcus aureus bacteria.

In Situ growth of high-crystallinity MOF@CTF core-shell hybrid heterostructures and their application in photoelectrochemical sensing of vancomycin

Vancomycin is a first-line drug for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant bacterial infections. It is of great significance to develop rapid detection methods for vancomycin in different matrices. In this work, a novel method for the in-situ preparation of MOF@CTF core-shell hybrid heterogeneous structures was proposed and applied to the photoelectrochemical detection of vancomycin. The insolubility of the imine precursor structure in homogeneous solvents and the Lewis acidic centers in the MOF structure induced the initial arrangement of CTF on the surface of PCN-224. By encapsulating a layer of highly crystalline CTF structure onto the initial morphology of PCN-224, a MOF@CTF heterogeneous structure was formed. Importantly, the introduction of anthracene-based electron-donating groups into the CTF structure and the formation of a donor-acceptor system with triazine rings enhanced the photoconversion efficiency of the heterogeneous structure by establishing a continuous separated built-in electric field within the core-shell structure. The successful in-situ synthesis of the core-shell hybrid heterogeneous structure was confirmed through microscopic morphology, PXRD, XPS, and FT-IR. Furthermore, investigations into the semiconductor properties of the heterogeneous structure, including semiconductor type, bandgap, and photo-voltage, were conducted. Results showed that the heterogeneous structure exhibited a doubled photocurrent density compared to the original PCN-224. Additionally, a molecularly imprinted photoelectrochemical sensor (MIPECS) for vancomycin was constructed. Under optimized conditions, the sensor demonstrated a superior concentration response range (0.1 nM - 1 μM) and detection limit (0.031 nM, 3σ/S, n = 11). Simultaneously, the potential applicability of the sensor in animal-derived foods, serum, and environmental water samples was evaluated, yielding satisfactory results.

Simultaneous determination of quaternary phosphonium compounds and phosphine oxides in environmental water and solid samples by ultrahigh performance liquid chromatography–tandem mass spectrometry

Quaternary phosphonium compounds (QPCs) and phosphine oxides (POs) are emerging contaminants that are attracting increasing attention. In the present study, a method for the quantification of QPCs and POs in multiple environmental media was developed using ultrahigh performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Analytes were extracted from water samples using solid phase extraction, and for the solid samples, ultrasonic extraction was employed. Compared with analytical methods established by previous studies, the approach developed in this study is more suitable for the quantitative analysis of compounds along with high sensitivity. The method quantification limit reached 0.12–2.55 ng⋅L–1 in water samples and 0.004–0.10 ng⋅g–1 in solid samples. The recoveries of target analytes spiked at low, medium and high concentrations in water and solid samples were in the range of 56.4–120 %, with relative standard deviations below 20 % (n = 6). Furthermore, the validated method succeeded in applying to analyse of eight QPCs and four POs in real environmental samples. At least five QPCs and two POs were detected in each environmental medium. This quantitative method would assist in further investigations on the occurrence, migration and the source of QPCs and POs.

Chitosan-stabilized gold nanoparticles decorated with a thiodiacetic acid nanoprobe for selective detection of arsenic(iii) in rice and water samples.

A sensitive and selective method for the detection of arsenic(iii) (As3+) based on chitosan-stabilized gold nanoparticles (CS/AuNPs) decorated with a 2,2'-thiodiacetic acid (TDA) nanoprobe was developed and used to detect and indicate the contamination of rice, drinking water and environmental water samples. AuNPs were reduced and stabilized with CS and subsequently functionalized with TDA. As3+ interacted with the carboxylate group of TDA to form an As-TDA complex, inducing the aggregation of CS/AuNPs@TDA. The aggregation of CS/AuNPs@TDA was accompanied with a change in color from red to bluish purple and a shift in surface plasmon resonance wavelength from 525 nm to 645 nm. The response for the detection of As3+ was linear at concentrations from 10 to 1000 μg L-1 with a limit of detection of 6.1 μg L-1. The method exhibited selectivity toward As3+ among various cations (As5+, Cu2+, Fe3+, Fe2+, Hg2+, Al3+, Cr3+, Cd2+, Co2+, Ni2+, Pb2+ and Zn2+) and anions (Br-, Cl-, F-, SO4 2-, NO3 - and PO4 2-). The CS/AuNPs@TDA nanoprobe was applied to detect As3+ in rice, drinking water and environmental water samples. The results were consistent with those obtained via inductively coupled plasma-optical emission spectrometry (ICP-OES). Satisfactory recoveries ranging from 88.22% to 105.74% (RSDs of 0.25-2.99%) were obtained from spiked samples.