Practical Water Samples Research Articles

A “turn-on” fluorescence probe based on a novel hypochlorous acid-induced cyclization response mechanism, and its applications in real water samples and bioimaging in vitro and in vivo

Hypochlorous acid (HOCl), as an important reactive oxygen species (ROS), plays key roles in normal physiological activities. Simultaneously, HOCl is also an efficient and strong oxidant, and is widely used in disease prevention and disinfection. Nevertheless, abnormal expression or excessive intake of HOCl may cause some serious diseases. Accordingly, the high sensitivity and specificity detection of HOCl in organisms and the environment is significant for understanding its roles in biology and environmental protection. Herein, a novel responsive 1,8-naphthalimide-based fluorescence probe PNL for the detection of HOCl was reported by a novel recognition mechanism. In the presence of HOCl, the PET effect of PNL was inhibited by the HOCl-induced cyclization reaction, leading to the “turn-on” fluorescence response. The recognition mechanism of PNL towards HOCl was determined by HR-MS, and the fluorescence “turn-on” sensing mechanism was rationalized via DFT calculation. PNL possesses the advantages of short response time (10 s), excellent selectivity, low cytotoxicity and reliability at a wide range of pH (3.0–11.5). Furthermore, the quantitative determinations of HOCl in practical water samples were achieved via the smartphone using PNL as the probe. Most importantly, the applications of PNL in fluorescent imaging of HOCl in vitro and the visualization of HOCl in an inflammatory model were successfully demonstrated. The development of PNL would also provide more abundant design strategies for the construction of HOCl fluorescence probes in the future.

Sulfate radical-dominated colorimetric sensing platform for ultrafast and portable monitoring of tetracycline in environment

Tetracycline (TC) is one of the most frequently detected antibiotics in environmental. Monitoring the concentration of TC is essential for understanding environmental fate of antibiotics. In this work, bimetallic N-doped carbon catalysts of M/Co@NC (M= Ni, Mn, Cu, Zn, Fe) were rationally synthesized via molten salt-assisted pyrolysis. The distinctive synergistic interplay between Cu and Co endowed Cu/Co@NC superior activation capacity for peroxymonosulphate (PMS). Inspired by the advantages of sulfate radical (SO4•−), an original colorimetric sensing platform was developed by using PMS as oxidant and rhodamine B (RhB) as chromogenic agents. Notably, this platform achieved an ultrafast visual reaction within 60 s and exhibited broad pH applicability under pH 2–9. Then, leveraging a competitive inhibition mechanism, dual-mode colorimetric and fluorescent sensing platforms were established for TC detection under neutral conditions. The fluorescent platform exhibited a reliable liner range from 0.001 to 15 μg/mL with limit of detection of 2 ng/mL. Excellent selectivity was found for TC even among different antibiotics. Theoretical calculations elucidated that the superior selectivity arises from a higher electrophilic attack (f-) of TC. Based on these finding, a smartphone-assisted test strip was developed and successfully deployed for the rapid monitoring of TC in practical water samples. This work not only synthesized an efficient PMS activator, but also proposed a novel visual sensing mode with ultrafast detection times, wide pH applicability and portable operation.

Dual-mode fluorescence and colorimetric sensor based on a novel Wurster-type twisted covalent organic framework for determination of HSO4ˉ with excellent selectivity and sensitivity in water and serum

A novel wurster-type twisted covalent organic framework (TNCOF) composed of N, N, N', N'-tetrakis(4-aminophenyl)-1,4-benzenediamine and 2,6-naphthalenedicarbaldehyde was synthesized and characterized. TNCOF exhibits exceptional crystallinity, as well as remarkable thermal and chemical stability. TNCOF in 1,4-dioxane exhibits highly selective and sensitive “on-off” fluorescent and colorimetric sensing ability towards HSO4ˉ over the other anions with fast response time. The fluorescence color of TNCOF suspension changes from pink to blue under the 365 nm UV lamp. Meanwhile, the color also changes under day light from grapefruit color to colorless. Both the fluorescence intensity at 597 nm and absorbance at 255 nm are linear relationship against the concentration of HSO4ˉ over a broad range, with lower limits at the micromolar level. The XPS, FTIR spectra and DFT calculation prove that TNCOF forms complex with HSO4ˉ via the hydrogen bonding. TNCOF demonstrates high recovery for detecting HSO4ˉ in practical water samples and serum, making it a suitable chemosensor for the identification and detection of HSO4ˉ.

A new oligo(N,O-donor)-like ratiometric fluorescent probe with FRET effect for dual-channel recognition of B4O72- ions in practical water samples

B4O72- ions are widely found in various production and living environments, and can cause serious effects on human health. For this reason, it is necessary to develop a high-efficiency method for the detection of B4O72- ions. Here a oligo(N,O-donor)-like dual-channel ratiometric fluorescence probe H3L was designed and synthesized for the detection of B4O72- ions in environmental samples. The recognition of B4O72- is based on the FRET effect by the probe H3L, the naphthalene ring partially serves as an energy donor, benzene ring partially serves as an energy acceptor, and phenolic oxygen acts as a reaction site for B4O72-. The probe H3L mainly displays the blue fluorescence of the donor; the presence of the B4O72- ions turns on the FRET effect, which will lead to yellow fluorescence of the benzene ring acceptor, enabling a ratiometric fluorescence recognition process. The probe has a large Stokes red shift (Δλ = 123 nm), which makes the emission wavelength after red shift more than 500 nm, and the obvious colourless to yellow color change can be observed by naked eyes, which solves the background fluorescence interference problem of short-wavelength fluorescence probe. At the same time, the probe has high selectivity and high sensitivity (low detection limit of 17.3 nM). In addition, we have successfully used this probe to detect B4O72- ions in actual samples. These results showed that the probe has a broad application prospect.

Dielectric barrier discharge plasma promotes disinfection-residual-bacteria inactivation via electric field and reactive species

Traditional disinfection processes face significant challenges such as health and ecological risks associated with disinfection-residual-bacteria due to their single mechanism of action. Development of new disinfection processes with composite mechanisms is therefore urgently needed. In this study, we employed liquid ground-electrode dielectric barrier discharge (lgDBD) to achieve synergistic sterilization through electric field electroporation and reactive species oxidation. At a voltage of 12 kV, Pseudomonas fluorescens (ultraviolet and ozone-resistant) and Bacillus subtilis (chlorine-resistant) were completely inactivated within 8 and 6 min, respectively, surpassing a 7.0-log reduction. The lgDBD process showed good disinfection performance across a wide range of pH values and different practical water samples. Staining experiments suggest that cellular membrane damage contributes to this inactivation. In addition, we used a two-dimensional parallel streamer solver with kinetics code to fashion a representative model of the basic discharge unit, and discovered the presence of a persistent electric field during the discharge process with a peak value of 2.86 × 106 V/m. Plasma discharge generates excited state species such as O(1D) and N2(C3Πu), and further forms reactive oxygen and nitrogen species at the gas-liquid interface. The physical process, which is driven by electric field-induced cell membrane electroporation, synergizes with the bactericidal effects of reactive oxygen and nitrogen species to provide effective disinfection. Adopting the lgDBD process enhances sterilization efficiency and adaptability, underscoring its potential to revolutionize physicochemical synergistic disinfection practices.

A smartphone-based nanoenzyme-modulated aptasensor using an infrared camera for rapid detection of kanamycin

The detection of antibiotics in water is crucial to ensure the safety of drinking water and prevent the spread of antibiotic resistance in the environment. In this study, we present a novel strategy for the selective and sensitive detection of kanamycin (KAN) in water by combining infrared thermography with aptamer detection technology. The aptamers specific to KAN were immobilized on the surface of gold nanoparticles (AuNPs), thereby enhancing the catalytic activity of AuNPs in the 3,3′,5,5′-tetramethylbenzidine (TMB)-hydrogen peroxide system to produce oxidized TMB with photothermal conversion capability. KAN competitively binds to the aptamer and modulates the catalytic capacity of the AuNPs surface, resulting in different photothermal conversion capacities of the final solution. Under near-infrared laser irradiation, the target KAN concentration is converted into a measurable thermal signal. To fabricate a portable sensing setup, we integrated the device with a smartphone. The aptasensor can selectively detect KAN with a limit of detection of 1.55 ng·mL−1 and a limit of quantification of 13.62 ng·mL−1. The detection time of our sensor is real time with a reaction time of 30 min. It demonstrates excellent stability and recoveries ranging from 96.9 % to 106.1 % for practical water samples. This portable aptasensor offers rapid detection, simplicity, and affordability, enabling real-time analysis of antibiotic residues in water.

A novel electrochemical sensing method based on an amino-functionalized MXene for the rapid and selective detection of Hg2.

Mercury is a highly toxic element that is widely present in all types of environmental media and can accumulate in living organisms. Prolonged exposure to high levels of mercury can lead to brain damage and death, so the detection of mercury is of great importance. In this study, a cost-effective and easy-to-operate electrochemical sensing method was successfully developed based on an amino-functionalized titanium-based MXene (NH2-Ti3C2Tx) for the rapid and selective detection of Hg2+ that could have a coordination effect with the -NH2 group of NH2-Ti3C2Tx to promote the efficient accumulation of Hg2+. In this strategy, the NH2-Ti3C2Tx was first modified on glassy carbon electrodes (GCE) to fabricate the electrochemical sensor. Benefiting from the excellent electrical conductivity, abundant active sites, and strong adsorption capacity performance of the NH2-Ti3C2Tx, the NH2-Ti3C2Tx modified GCE (NH2-Ti3C2Tx/GCE) exhibited satisfactory selectivity and enhanced square wave anodic stripping voltammetry (SWASV) measurement for the rapid detection of trace amounts of Hg2+ in aqueous solutions. The electrochemical sensor was found to be capable of detecting Hg2+ with a low detection limit of 8.27 nmol L-1 and a linear range of 0.5 μmol L-1 to 50 μmol L-1. The response time of the electrochemical sensing method was 308 s. In addition, the electrochemical sensing method has good selectivity, repeatability and stability, and multiple heavy metal ions have no effect on its detection, with repeatability and stability RSDs of 1.68% and 1.43%, respectively. Furthermore, the analysis of practical water samples demonstrated that the developed method was highly practical for the actual determination of Hg2+ with recoveries in the range of 99.22-101.90%.

β-Diketone functionalized covalent organic framework for detection of europium(III) and successive detection of tetracycline antibiotics

A new covalent organic framework (M-TT-COF) was designed and prepared by grafting Meldrum’s acid on the scaffold of TT-COF via esterification. M-TT-COF retained the crystal structure and high thermal stability of TT-COF. M-TT-COF as a “turn-on” fluorescence sensor can selectively identify and detect Eu3+ and tetracycline antibiotics in successive mode, the other metal ions, anions and antibiotics did not exert an obvious influence on the selective detection performance. The sensing performance has high sensitivity with low detection limits, 3.94 μM of M-TT-COF for Eu3+ and 0.56 μM of Eu@M-TT-COF for tetracycline antibiotics (oxytetracycline). In addition, both M-TT-COF and Eu@M-TT-COF have satisfactory recovery in the detection of Eu3+ and tetracycline antibiotics in the practical water samples, respectively. The mechanism of the fluorescence enhancement is attributed to the energy transfers from the β-diketone structure to Eu3+. This work successfully exploits a covalent organic framework as a “turn-on” fluorescence sensor in the identification and detection of rare earth metal ions and antibiotics.

Self-assembly flexible SERS imprinted membrane based on Ag nanocubes for selective detection of microcystin-LR.

Silver nanocubes monolayer-modified polydimethylsiloxane (Ag NC/PDMS) flexible SERS substrates have been prepared by a three-phase interface self-assembly procedure. The combination of this method with membrane technology brings nanoparticles in close proximity, densely, and regularly arranged in monolayers over a large area, leading to excellent SERS properties. Considering the complexity of practical detection, molecular imprinted polymers (MIPs) were anchored on the surface of SERS substrate and applied to selective detection of microcystin-LR (MC-LR). It isworth mentioning that the SERS imprinted membranes (AP-MIMs) were still clearly detected at aconcentration of 0.1µg·L-1 of MC-LR in drinking water, and the detection limit was as low as 0.0067µg·L-1. The substrate exhibited excellent uniformity with a relative standard deviation (RSD) of 6.1%. In the presence of interference molecules, AP-MIMs exhibited excellent selectivity for MC-LR. Furthermore, in the spiking and recovery tests of practical lake water samples, the method showed excellent recoveries ranging from 96.47 to 105.31%. It has been demonstrated that the prepared AP-MIMs can be applied to sensitive and specific detection of trace amounts of MC-LR in drinking water.

Oxygen vacancies modulation Se-doped ZnMn2O4/NC with high oxidase-mimicking activity for tetracycline hydrochloride detection

Convenient and reliable tetracycline hydrochloride (TC) detection is necessary due to its harmfulness. Herein, Se-doped ZnMn2O4/nitrogen carbon (NC) catalyst was effectively synthesized through step-by-step calcination in an N2 atmosphere, which possessed enhanced oxidase mimetic activity. After Se doping, the oxidase-like activity of the catalyst is 2.75-fold and 1.64-fold higher than that of the Zn-Mn ZIF precursor and ZnO/MnO/NC, respectively. The Michaelis–Menten constant for Se-doped ZnMn2O4/NC with TMB substrate is 0.047 mM, which has higher affinity towards TMB than other manganese-containing materials. More oxygen vacancy in Se-doped ZnMn2O4/NC was recognized as the main sites for activating oxygen to produce reactive oxygen species to oxidize TMB. Based on the inhibitory effect of TC on the colorimetric system of TMB/Se-doped ZnMn2O4/NC, a simple method for TC detection was proposed with a wide linear range of 2–100 µM and 100–500 µM and a low detection limit of 0.88 µM. The method exhibited good selectivity to TC among some ions and antibiotics, and TC in the practical water samples was successfully detected.

BiW9-based electrochemical sensor for the simultaneous determination of cadmium(II) and lead(II) in water

Heavy metal pollution has been considered as an important concern for the environment, and effective detection methods are crucial for the sensitive and selective determination of toxic heavy metal ions such as lead and cadmium. Among various detection methods, electrochemical stripping analysis has been regarded as an efficient approach for the determination of heavy metal ions, especially on bismuth-based materials. Polyoxometalates have been received lots of attention and widely applied in many fields. However, the bismuth-containing polyoxometalate has never been reported for the determination of heavy metals. In this study, Na9[BiW9O33]·16H2O (BiW9) was utilized to construct an electrochemical sensor towards the simultaneous detection of Cd(II) and Pb(II). The prepared bismuth-containing polyoxometalate BiW9 was characterized by X-ray diffraction and Fourier transform infrared spectroscopy, which was then casted onto the surface of glassy carbon electrode (GCE) to test the electrochemical behavior by square wave anodic stripping voltammetry. The results showed that BiW9/GCE possesses a good electroanalytical performance for the simultaneous determination of Cd(II) and Pb(II) with wide linear ranges and low detection limits. Moreover, the sensor shows good selectivity, repeatability, reproducibility and stability, and owns broad application prospects in the detection of practical water samples. The proposed bismuth-based polyoxometalate fabricated electrochemical sensor exhibits good performance towards the heavy metal ions detection, which may benefit the further application in practical fields.

Surfactant-Assisted Synthesis of Bismuth Oxychloride Nanoflowers for Electrochemical Sensing of Heavy Metal Ions

Heavy metal ion contamination of drinking water is a significant, invisible threat to public health which requires active and decentralized monitoring with high sensitivity, accuracy and reliability. The government and regulatory agencies actively survey and maintain established limits on heavy metal contamination, but generally prioritizing localized hotspots in high-risk communities. Their characterization techniques are typically expensive and inaccessible to the public, requiring specialized training and extended sample shipping times, with a purview restricted to public infrastructure. As plumbing systems corrode and contaminants leach into drinking water systems, independent means of oversight are becoming increasingly vital in effectively identifying and mitigating toxic exposure. In this work we propose the development and application of a high surface area bismuth oxychloride nanoflower for the electrochemical detection of zinc and lead ions in drinking water. The flower structure was synthesized via hydrolysis of bismuth chloride salt in a micellar environment of sodium dodecyl sulfate, followed by aqueous chemical reduction and transformation to metallic bismuth. The size and uniformity of the synthesized nanoflower was characterized with scanning electron microscopy (SEM), and the composition and microstructure were investigated using energy dispersive x-ray spectroscopy (EDS) analysis and x-ray diffraction (XRD). The nanoflowers were deposited onto a glassy carbon electrode and coated with a protective Nafion layer, prior to cyclic voltammetry analysis of analyte ion reactivity, achieving detection of lead and zinc ions in buffer and practical drinking water samples. These results indicate the viability of bismuth-based nanoflower structures for portable, accessible detection of heavy metal ions, with enhanced sensitivity.

Effective peroxydisulfate activation by CQDs-MnFe2O4@ZIF-8 catalyst for complementary degradation of bisphenol A by free radicals and non-radical pathways

The present study reported fabrication of novel carbon quantum dots-MnFe2O4@ZIF-8 (CQDs-MFO@ZIF-8) by using co-precipitation hydrothermal method for activation of peroxydisulfate (PDS) to degrade bisphenol A (BPA), one of important emerging organic pollutants in water environment. CQDs-MFO@ZIF-8 served as a highly efficient thermal activated PDS catalyst with high catalytic degradation efficiency, reusability and stability. The catalyst achieved almost completely removal of 20.0 mg/L BPA within 5.0 min, and the degradation efficiency remained higher than 83% after 5 consecutive cycles. Free radicals (•OH, SO4•− and •O2−) and non-free radicals (1O2) were generated in the thermal PDS-activation system, in which singlet oxygen (1O2) played a dominant role in the degradation of BPA. The potential toxicity of BPA degradation intermediates was analyzed upon the culture of E. coli and Chlorella sorokiniana by using Ecological Structure-Activity Relationship Model (ECOSAR) program. The catalytic performances of BPA degradation by CQDs-MFO@ZIF-8 were evaluated for treatment of different practical water samples to further verify the feasibility of practical applications. This study provides proof-in-concept demonstration of new nanomaterials for enhanced catalytic water decontamination.

A novel nitrogen-doped carbon dots as “on-off-on” fluorescent sensor for ultrasensitive and visual quantitative detection of mercuric (II) and glutathione

A novel nitrogen-doped carbon dots (NCDs) was prepared composed of anhydrous citric acid and 2-amino-1-H-benzimidazole with solid state method. The XPS and FT-IR spectra indicate that lot of chelating groups such as -OH, -COOH and -NH2 are attached on the surface of NCDs. NCDs exhibited the characteristic fluorescence property and its fluorescence spectra gradually red-shifted with the increase of excitation wavelengths. The prepared NCDs in water solution has highly selective “turn-off” fluorescence response towards Hg2+ over the other metal ions and common anions with a low detection limit of 3.50 μM. Furthermore, NCDs presented the successive identification and detection capability, NCDs@Hg2+ displayed highly selective “turn-on” fluorescence response towards the bioactive glutathione (GSH) over the other amino acids with a low detection limit of 3.43 μM. The “turn-off” fluorescence of NCDs was caused by the selective coordination with Hg2+ through both static and dynamic quenching mechanisms, and the fluorescence recovery can be attributed to the removal of Hg2+ from the complex NCDs@Hg2+ by GSH. The hydrogel films containing NCDs and NCDs@Hg2+ can semi-quantitatively detect Hg2+ and GSH in micromolar level with naked eyes under UV lamp, respectively. In addition, the prepared NCDs have satisfactory recovery in detection of Hg2+ and GSH in practical water samples and human serum samples. This work proves the N-doped carbon NCDs are efficient material as fluorescence chemosensors to identify and detect metal ions and bioactive substances in practical samples.

The enhancing energy efficiency of sulfadiazine degradation using a DBD-contact plasma treatment process

Nonthermal plasma has attracted extensive attention because of its ability to remove emerging organic micropollutants. However, its high amount of energy consumption severely limits its economic feasibility. In this study, sulfadiazine degradation was achieved in an optimized dielectric barrier discharge (DBD)-Contact system. The sulfadiazine removal in the DBD-Contact/peroxymonosulfate (PMS) system reached 91.8% within 15 min. Compared to a conventional DBD system, the energy efficiency (G50) of the DBD-Contact/PMS system was 4.37 times greater, which meant a saving of 77.17% in electricity consumption. The reactive species generated by discharge plasma were identified as mostly excited nitrogen species in the gas phase, and after transferred to the water phase, OH and SO4− played an important role in the sulfadiazine removal. The hydroxylation of the S-N bond and the nucleophilic reaction of the pyrimidine ring were proposed as mechanisms for the sulfadiazine degradation, and the developmental and acute toxicity was significantly reduced after treatment. Furthermore, the DBD-Contact/PMS system showed good applicability in a wide pH range and complex practical water samples. This study finds that the DBD-Contact/PMS system can degrade antibiotics with high efficiency and low energy consumption and provides new insights for the practical application of DBD technology in water treatment.

Robust solvatochromic carbon quantum dots for selective detection of water and Sn4+ and specific lipid imaging.

Developing carbon quantum dots (CQDs) with the solvatochromic effect and exploring multifunctional applications remains challenging. Herein, robust solvatochromic carbon quantum dots (RS-CQDs) with emission shift up to ∼62nm from yellow to red was fabricated by the hydrothermal method. The RS-CQDs was used to detect water and Sn4+ in the linear ranges and limits of detection of 2.0-97.6% and 0.14% and 6.24-53.18μM and 66.3nM, respectively, and was further applied to determine Sn4+ in practical water samples with satisfactory results. In addition, RS-CQDs exhibited bright red emission in oil media with a 9.7-fold increase in fluorescence relative to aqueous media, making them a wash-free probe for specifically staining lipids. Compared to the commercial lipid marker BODIPY 493/503, the RS-CQDs-based probe has significant advantages, such as longer emission, larger Stokes shift, and better photostability, ensuring that RS-CQDs-based marker can implement real-time and wash-free monitoring and imaging of lipids in living cells, liver tissues, zebrafish embryos, and zebrafish larvae. This study provides a novel research direction for the development of metal-doped CQDs by demonstrating RS-CQDs as the viability of fluorescence probes for water and Sn4+ detection and the efficiency of RS-CQDs as a fluorescent marker for lipid imaging.

Porous Organic Frameworks Constructed by the Synergetic Effect of Covalent Bonds and Hydrogen Bonds for the Selective Identification and Detection of Explosives.

Covalent organic frameworks (COFs) and hydrogen-bonded organic frameworks (HOFs) have emerged as novel platforms for material design and functional explorations. Here, we report an unconventional structural organic framework (named CHOF-1) combined with 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 5-hydroxyisophthalaldehyde (HP) through the synergetic effect of covalent bonds and hydrogen bonds. CHOF-1 contains two different pores and is an eclipsed AA-stacking model with high thermal stability. It exhibits selective "turn-off" and red shift fluorescence responses toward 4-nitrophenol (4-NP) and 2,4,6-trinitrophenol (TNP) in ethanol, respectively, and the low detection limit was 8.78 μM for 4-NP and 11.1 μM for TNP. It has satisfactory recovery in the detection of 4-NP and TNP in practical water samples. The fluorescence quenching of CHOF-1 caused by 4-NP is attributed to the absorption competition quenching (ACQ) mechanism. In the structure of CHOF-1, the hydroxyl of TNP has strong acidity and can form strong hydrogen bonds with the unreacted NH2. Then, the crystalline structure of CHOF-1 decomposed and the electron structure of the photophore changed; thus, the fluorescence spectra red-shifted. This is a novel example of a covalent bond and hydrogen bonds combined organic framework (CHOF). This work not only demonstrates a synthesis strategy of the first novel structural organic framework through the synergetic effect of covalent bonds and hydrogen bonds but also provides a fluorescent sensing material for the detection of explosives 4-NP and TNP with high selectivity and sensitivity.

A dual-channel chemosensor based on diarylethene bearing a benzoisothiazole unit for detecting CO32−

A new photochromic diarylethene with a benzoisothiazole unit has been designed and synthesized. The diarylethene could act as a colorimetric and fluorescence dual-channel chemosensor for CO32− with short response time, high selectivity, and excellent sensitivity. Moreover, the response mechanism of the chemosensor to CO32− was studied systematically in methanol. The chemosensor could be used to the detection of CO32− in practical water samples, and also be made into test papers for CO32− recognition with high efficiency.

Quantifying nitroaromatics via terminating their photoreduction catalyzed by Eosin Y

The environmental and safety concerns caused by nitroaromatic compounds (NACs) require a sensitive, reliable, and easy-to-use method for their detection. In this work, we observed that an ultrafast photobleaching occurred when the photoreduction of NACs catalyzed by eosin Y (EY) was terminated. Based on such a semi-cycle photocatalysis, a colorimetric method was developed to quantify NACs with a linear relationship between the pseudo-first-order kinetic constant (kapp) of EY photobleaching and NACs concentration. This method exhibited a high sensitivity, low detection limit (6.57 ppb), and good anti-interference ability in the presence of various ions or organics in water matrices, enabling satisfactory quantification results for practical water samples. Moreover, the EY-based photocatalysis mechanisms inspires that the ultra-fast EY decoloration in the NAC solution was attributed to the fragment of the photoexcited EY molecule. This work provides a feasible photocatalysis-based NAC detection approach by applying a “off-the-shelf” probe.

Porphyrin-based magnetic porous organic polymer for efficient magnetic solid phase extraction of nonsteroidal anti-inflammatory drugs from water

The ubiquitous occurrence of nonsteroidal anti-inflammatory drugs (NSAIDs) in the environmental water system has drawn significant concerns due to their adverse effects. The accurate monitoring the content of them is of great significance but challenging in terms of the complex matrix and trace concentration. In this work, a porphyrin-based magnetic porous organic polymer composite (PM-POP) was prepared through a solvent-free synthetic method. Owing to the highly porous structure and strong affinities, the as-prepared PM-POP could be utilized as a highly efficient adsorbent for the magnetic solid phase extraction (MSPE) of NSAIDs. Combining with the high-performance liquid chromatography separation with ultraviolet detector (HPLC-UV), a sensitive analytical method was established, which exhibited wide linear ranges (0.1–400 μg/L) and large enrichment factors (EFs) (39.5–82.9 folds) along with good precision (intra-day RSD ≤ 4.9%) and repeatability (inter-day RSD ≤ 8.4%). Ultimately, it was applied to determinate trace NSAIDs in practical water samples successfully, demonstrating its good application prospect in environmental analysis.