Aqueous Environment Research Articles

Enhanced interfacial electric field via sulfur vacancies modified ZnIn2S4-Vs@NiIn2S4 S-scheme photocatalysts for simultaneous H2 evolution and benzyl alcohol oxidation

Designing and developing efficient photocatalysts for H2 evolution and simultaneous oxidation of benzyl alcohol (BA) in aqueous environments provides a cutting-edge strategy for green synthesis. Nevertheless, the photocatalysts suffer from the low photoconversion efficiency because of the sluggish dynamics and repaid recombination of photogenerated charge carriers, which hindering their widespread applications. To address the limitation, a multifunctionnal sulfur vacancies (SVs) modified ZIS-Vs@NIS S-scheme heterojunction with a strong interfacial electric field effect was synthesized to use photocatalytic H2 production and BA oxidation, simultaneously. Experimental analysis supports that the synergistic effect of SVs and S-scheme heterojunction engineering result in a suitable energy band structure alignment and larger Fermi level potential difference. Those factors can realize effective charge transfer and separation, and enhance the photocatalytic performance. As anticipated, ZIS-Vs@NIS exhibited a superior photocatalytic performance with H2 and benzaldehyde (BAD) yields up to 168.1 and 146.1 μmol under the simulated solar-light irradiation for 1.0 h, respectively, which are approximately 13.3 and 11.8 times higher than pristine ZIS. Moreover, the photocatalytic H2 evolution coupled with BA oxidative dehydrogenation mechanism via S-scheme heterojunction over ZIS-Vs@NIS is also demonstrated in detail.

Enhancing photocatalytic activity via formation of heterojunctions introduced through postmetalation of metal organic frameworks with silver ions

The postmetalation of silver in zinc and manganese-based metal–organic frameworks (MOFs) represents a versatile and efficient approach for enhancing the degradation of methylene blue (MB) pollutant in aqueous environment. In the present study, zinc, manganese, and their bimetallic MOFs are synthesized using the solvothermal method. Subsequently, silver ions are incorporated into the synthesized MOFs. A suite of characterization techniques is employed to analyze the resulting material. Among the three silver loaded MOFs, Ag-mixed bimetallic MOF (Ag-BM) exhibits the least band gap of 2.28 eV, possessing a greater propensity for light absorption. The particle size of Ag-BM lies in the nanometer range, and it possesses the largest surface area. X-ray diffraction depicts the successful integration of Ag into MOF structure. The synthesized samples are used for degrading MB. Ag-BM outperforms the other MOFs in decomposing MB, with a degradation percentage of 91.8% in 120 min. The degradation process follows the first-order kinetics depicting that the rate of degradation positively correlates with the dye concentration remaining in the solution. Employing a reactive species quenching experiment with scavengers, hydroxyl radicals were identified as the principal active species responsible for MB degradation by Ag-BM.

Bubbles Acting as Micro End‐Effectors for Dexterous Manipulation and Sensing in Aqueous Environment

Bubbles Acting as Micro End‐Effectors for Dexterous Manipulation and Sensing in Aqueous Environment

Exploring Astaxanthin-Loaded Nanoformulations for Skin Targeting: Present Progress and Prospective Directions

This comprehensive review provides information on astaxanthin-loaded topical nanocarrier- based formulations for targeted skin enhancement. Astaxanthin, a potent carotenoid derived from microalgae, has garnered considerable attention for its multifaceted potential in skincare, particularly when incorporated into nanocarriers. These nanocarriers, like nanoemulsions, micelles, hydrogels and nanoparticles, have revolutionized the field of dermatology by providing innovative solutions to overcome the limitations associated with astaxanthin's solubility and stability. Astaxanthin's exceptional antioxidant properties, including its ability to neutralize free radicals within both lipid and aqueous environments, make it a compelling bioactive ingredient for combatting oxidative stress, a central contributor to skin aging and various dermatological conditions. The nanoscale size of these carriers facilitates enhanced skin penetration, controlled release, and improved bioavailability, thereby augmenting astaxanthin's therapeutic efficacy. This review meticulously explores the mechanistic insights behind astaxanthin's enhanced delivery and its multifaceted benefits, including photoprotection, anti-inflammatory effects, and wound healing properties. The diverse applications of astaxanthin-loaded nanocarriers in skincare, spanning anti-aging formulations, UV protection, scar healing, and wound repair, are elucidated. Safety considerations are also addressed, drawing from an extensive analysis of preclinical and clinical studies. The review provides valuable insights into optimal concentrations, formulation strategies, and regulatory aspects governing astaxanthin-loaded nanocarriers in skincare products.

LaCo0.95Mo0.05O3/CeO2 composite can promote the effective activation of peroxymonosulfate via Co3+/Co2+ cycle and realize the efficient degradation of hydroxychloroquine sulfate

Hydroxychloroquine sulfate (HCQ) is extensively utilized due to its numerous therapeutic effects. Because of its properties of high solubility, persistence, bioaccumulation, and biotoxicity, HCQ can potentially affect water bodies and human health. In this study, the LaCo0.95Mo0.05O3-CeO2 material was successfully prepared by the sol–gel process, and it was applied to the experiment of degrading HCQ by activating peroxymonosulfate (PMS). The results of characterization analysis showed that LaCo0.95Mo0.05O3-CeO2 material had good stability, and the problem of particle agglomeration had been solved to some extent. Compared with LaCo0.95Mo0.05O3 material, it had a larger specific surface area and more oxygen vacancies, which was helpful to improve the catalytic activity for PMS. Under optimal conditions, the LaCo0.95Mo0.05O3-CeO2/PMS system degraded 95.5 % of HCQ in 10 min. The singlet oxygen, superoxide radicals, and sulfate radicals were the main radicals for HCQ degradation. The addition of Mo6+/Mo4+ and Ce4+/Ce3+ promoted the redox cycle of Co3+/Co2+ and enhanced the degradation rate of HCQ. Based on density functional theory and experimental analysis, three HCQ degradation pathways were proposed. The analysis of T.E.S.T software showed that the toxicity of HCQ was obviously reduced after degradation. The LaCo0.95Mo0.05O3-CeO2/PMS system displayed excellent reusability and the ability to remove pollutants in a wide range of real-world aqueous environments, with the ability to treat a wide range of pharmaceutical wastewater. In summary, this study provides some ideas for developing heterogeneous catalysts for advanced oxidation systems and provide an efficient, simple, and low-cost method for treating pharmaceutical wastewater that has good practical application potential.

Dissolved ammonia catalyzes proto-dolomite precipitation at Earth surface temperature

Marine carbonate rocks are the major reservoir of carbon through CaCO3 and CaMg(CO3)2 precipitation extracting CO2/HCO3- from the atmosphere/oceans; hence dolomite is one of the major sinks in the global carbon cycle. Most ancient dolomite has been considered as mainly precipitated under Earth surface conditions. Previous studies have demonstrated that microbes can mediate dolomite formation. However, the “microbial dolomite” model is not sufficient to explain the dolomite that shows no or little evidence of a microbial origin. Although attempted for decades, the synthesis of inorganically-produced dolomite at normal temperatures (<50 °C) has been relatively unsuccessful. Hence, this "dolomite enigma" has been one principal research focus this century. Here we demonstrate that NH3 catalyzes proto-dolomite precipitation inorganically with higher Mg/Ca molar ratios and CO32- activity at normal temperatures of 30 °C and 40 °C. NH3 dissolution increases the alkalinity of the solution and transformes into NH4+ ions, which prefer to bond with H2O on Mg[(H2O)6]2+ rather than free H2O, thus releasing Mg2+ to facilitate proto-dolomite nucleation. Furthermore, the low dielectric constant and low dipole moment allow NH4+ absorbed on crystal surfaces to lower the energy barrier of Mg[(H2O)6]2+ dehydration, promoting proto-dolomite nucleis growth. The system for proto-dolomite precipitation in our experiments closely simulates the natural aqueous environment. This study brings new insights to understanding the mechanisms of dolomite precipitation in natural waters.

The Sword of Damocles: Microplastics and the molecular dynamics of sulfamonomethoxine revealed

In recent years, the environmental impact of microplastics (MPs) and antibiotics (ATs) as pollutants cannot be ignored. In order to evaluate the carrier effect of MPs in the aqueous environment, three MPs, polyamide (PA), polyethylene (PE) and polyethylene terephthalate (PET), were selected in this study, and their structures were analyzed by means of characterization. A preliminary description of their interactions with sulfamonomethoxine was carried out by adsorption kinetics and isotherm fitting. The dominance of non-bonding capacity (van der Waals and electrostatic interaction forces) in the adsorption process was demonstrated using molecular dynamics (MD) simulations and density functional theory (DFT), with the interaction strengths ranked as PA > PE > PET, respectively. PA is less adsorbent stable at the molecular level but exhibits the largest adsorption capacity influenced by the characterized structure and multiple interaction forces. PET possesses a stronger stability and is not easily replaced by other substances. This will help to further understand the complex effect mechanism between MPs and organic pollutants, and provide an important reference for the prevention and control of environmental pollution.

Photocatalytic antibiotic degradation in coated open microchannels by applying 2D and 3D flow modeling with kinetics

The accumulation of active pharmaceutical ingredients in the aqueous environment is a serious problem that will become even more concerning in the future. In this work, the photocatalytic degradation of ciprofloxacin (CIP) in aqueous solution was assessed over P25-TiO2 coated open microchannels with gravity-driven flow under UV-A irradiation. The deposition of different amounts of TiO2 in the microchannels was carried out via a facile, self-developed procedure. The degradation kinetics of ciprofloxacin was described via the Langmuir-Hinshelwood mechanism. Since the flow characteristics in the microchannel had influence on the concentration distribution of CIP in the microchannel, the coupled momentum and mass conservation law was solved numerically in MATLAB 2023a (2D case) as well as in ANYS Fluent 2023 R1 (2D and 3D cases). Although the implemented 2D model in MATLAB 2023a allowed the preliminary estimation of the selected kinetic parameters, namely adsorption equilibrium constant and specific Langmuir-Hinshelwood rate constant, the sensitivity of the model was not satisfactory which was attributed to the empirical correlations used for the estimation of the external mass transfer coefficient. The 2D and 3D models in ANSYS Fluent 2023 R1 predicted efficiently the outlet concentration of ciprofloxacin for different inlet CIP concentrations and liquid phase flow rates. Therefore, the as developed 2D and 3D models in ANSYS Fluent 2023 R1 can be used for the design of reactors containing coated microchannels with gravity-driven flow for photocatalytic degradation of active pharmaceutical ingredients.

Effect of Alpha Hydroxy Acids as Dentin Conditioning Agents on Growth Factor Release: An In Vitro Study.

The study aimed to evaluate the effects of alpha hydroxy acids and chelating agents on dentin conditioning for the release of growth factors. The agents used for dentin conditioning included 17% ethylenediaminetetraacetic acid (EDTA), 10% glycolic acid (GA), 10% citric acid (CA), and 5% maleic acid (MA). Forty horizontally sectioned (SV1) human dentine slices were conditioned for 5 and 10 minutes so that the growth factor liberation reached quantifiable levels. Transforming growth factor beta-1 (TGF-β1) release and surface exposure were quantified by enzyme-linked immunosorbent assay (ELISA). Growth factor measurement required immediately removing the solutions from each of the 48-well plates (with consistent dentine surface area and weight) and freezing at -20°C so that ELISA measured the growth factors. After 5-min conditioning of dentine slices, CA was the most effective agent for growth factor release into the aqueous environment as measured by ELISA (post hoc Tukey's test p<0.05). Furthermore, dentine slices subjected to GA treatment for the same duration of time showed noticeably lower surface levels of TGF-β1 in comparison to the other agents employed. Based on the findings of this in vitro study, a desirable biological growth factor-mediated effect may be gained when conditioning dentin with milder acidic or chelating agents such as CA, MA, and EDTA.

Isomer engineering of benzofuran derived AIE luminogens: Synthesis, mechanochromism, pH responsive fluorescent switching, cell-imaging and Fe3+ sensing

The influence of multiple factors often leads to the unexpected performances of the designed AIEgens. It is difficult to precisely conclude the influence of the substituted sites and role of isomers on the photophysical properties of the AIEgens which therefore brings uncertainty in the molecular design strategies. Isomer engineering of AIEgens is a less explored domain. There are only a few reports that substantiate the effects and positions of the substituents on the AIE properties. The present investigation explores two isomeric benzofuran-derived luminogens GBY-1 and GBY-4, both featuring a TPE moiety and showcasing AIE and AIEE properties respectively inherited from TPE. The isomeric effect resulting from TPE incorporation at different positions across benzofuran significantly influenced their photophysical properties, mechanofluorochromic properties, and AIE effect. Their distinctive luminogenic features were evident in mechanochromic property as well as in cancer cell imaging. GBY-1 was found to be uniformly dispersed in the cytoplasm, not co-localized with the nucleus, while GBY-4 accumulated near the cell membrane. Furthermore, post-functionalization of one of the luminogens, GBY-1, derived another AIEgen, GBY-5 with a dramatic improvement in the PLQE along with its ability to selectively sense Fe3+ in aqueous environments, within a detection limit of 0.00035 mM.

Exploring Sulphonated Calix[n]arenes as Catalysts in Organic Reactions

Catalysis plays a crucial role in modern chemistry, with macrocyclic compounds like calixarenes serving as key players in organic transformations through supramolecular chemistry. These macrocycles, synthesized from phenol and formaldehyde condensation, exhibit a variety of conformations, such as cone and partial‐cone, due to their flexible structures. Their effectiveness as catalysts arises from their lipophilic cavities and the ease of functionalization on both the upper and lower rims. Water‐soluble calixarenes, in particular, have gained attention for their ability to interact with hydrophobic cavities, facilitating molecular recognition in aqueous environments. A landmark achievement in this field was Shinkai's synthesis of water‐soluble calix[4]arene in 1984, which involved sulphonation using tert‐butyl groups, resulting in compounds known for their low toxicity and encapsulation capabilities. This review provides a comprehensive overview of the advancements in sulphonated calixarenes as catalysts, emphasizing their diverse applications and potential for future development. Key catalytic reactions and their substrate scopes are discussed, along with future perspectives on how these compounds can further revolutionize catalytic processes.

Smart sensing property of Eu3+-induced polyelectrolyte nanoaggregates on nitrofuran antibiotics in aqueous environments

Pollution of water with antibiotics is a very serious global issue. So, simple, fast, and ecofriendly detection of such pollutants in aqueous environments has aroused great attention. Several intriguing properties such as narrow emission band, large stokes shift, long luminescence decay time and resistance to photobleaching distinguishes europium-based materials from commonly used fluorophores in biology as a superior optical smart material for applications in diverse fields. Herein, strongly luminescent Eu3+-induced polyelectrolyte nanoaggregates (EINAP) were synthesized and successfully characterized. The biocompatible polysaccharides hyaluronic acid and chitosan are used to disperse organic europium complexes resulting in formation of hybrid nanoaggregates. As synthesized EINAP demonstrated excellent quantum yield (89.29 %) and luminescence lifetime (656 µs). The EINAP also have high sensitivity and low limit of detection with good analytical precision for nitrofuran antibiotics in aqueous environments. The luminescent nano sensor developed in this work could be a novel tool for assessment of antibiotic pollution in the environment. The overall sensing mechanisms for detection of nitrofurans in aqueous environments were found to be the combination of inner filter effect and photoinduced electron transfer respectively.

Self-assembled fluorescent Zn-MOF with high specific surface area based on the coordination interaction for sensitive detection and selective removal of tetracycline antibiotic in water

As one of most common used antibiotics, tetracyclines (TCs) have been widespread used in many fields. However, the abuse of antibiotics resulted in serious environmental pollutants. Therefore, it is of great significance to develop new materials for rapid detection and effective removal of tetracyclines. In this study, a step-by-step synthesis strategy was adopted to prepare a fluorescent LMOF material Znq2@ZIF-8, and it was well characterized. Znq2@ZIF-8 showed strong green emission and has large specific surface area, with excellent stability and good recyclability. The fluorescence of Znq2@ZIF-8 can be quenched with the addition of tetracycline (TC) in the aqueous environment, demonstrating good selectivity and strong interference resistance, with a limit of detection (LOD) of 0.13 μmol∙L−1. In addition, Znq2@ZIF-8 exhibits excellent adsorption and removal abilities for TC. As a result, Znq2@ZIF-8 enables the simultaneous detection and removal of TC in aqueous environments, providing a solution for future TC pollution in water.

OH radical initiated oxidative degradation of imidacloprid in the environment: An assessment of breakdown kinetics and environmental hazards

Imidacloprid (IMI) is a common neonicotinoid pesticide that acts via a similar mechanism of action to nicotine, a naturally occurring insecticide. It is therefore important to understand its chemical fate in the environment. Hydroxyl radicals (HO) are significant oxidizing species in natural aquifers due to their strong reactivity towards organic substrates. Therefore, principal photo-oxidation products are expected to form with the involvement of HO in the self-cleaning process of water in nature. Here quantum chemical calculations are used to examine the reaction of IMI with HO in the atmosphere and aqueous environments. It was found that the principal mechanism of the HO + IMI reaction is the hydrogen transfer that, in a two-step process, produces stable cations in the gas phase. Within the atmospheric temperature range of 253–323 K, the overall rate constants for the HO + IMI reaction decreased from 4.35 × 1010 to 2.13 × 1010 M−1 s−1. Consequently, IMI can undergo rapid gaseous degradation within a comparatively brief period of 2.81 × 10−4 – 5.75 × 10−4 years. However, differences in environmental temperature and pH in aqueous environments influence the processes, rate constants, and products of IMI breakdown by the HO radical. The data indicate that IMI breakdown by OH radicals is strongly temperature and pH-dependent, resulting in the generation of different reaction products. The results imply that at all pH levels, the interaction between IMI and the ambient HO radical in water produces toxic chemical species. According to the computed data, it appears that IMI and the vast majority of degradation products present potentially carcinogenic and/or mutagenic hazards, and they also lack downstream biodegradability.

Optimization of iron flocculation for enrichment of CyHV-2 in aquaculture water

Cyprinid herpesvirus 2 (CyHV-2) is an important infectious virus endangering the farmed Carassius species industry. The enrichment and identification of CyHV-2 in the water is a vital means of early warning diagnostics, which is helpful to aquatic diseases prevention and control. In this study, we employed and optimized iron flocculation to enrich the concentrations of CyHV-2 in aquaculture water. Different Fe3+ concentrations (0.5, 1.0, and 10.0 mg/L), various membrane filters (mixed cellulose ester, glass fiber, nylon microporous filter membrane), different elution buffers containing reductants (ascorbate, citrate, DL-malate, and their combinations with EDTA or TE buffer) were compared to check the recovery yield of CyHV-2. Viral genome quantitation was determined using quantitative real-time PCR. The results showed that Fe3+ concentration of 1.0 mg/L, the glass fiber and citrate-TE were determined to have high efficiency and stable recovery yield. To evaluate infectious CyHV-2 viral titres, crucian carps (Carassius auratus) were intraperitoneally injected with CyHV-2. The mortality rate was 100 % at 9 days postinoculation (dpi) with the 96.7 % detection of CyHV-2 in the pooled tissues. The histopathological phenotype showed necrotic cell death in the liver, spleen and kidney. The CyHV-2 genome was ranging from 101.1 to 107.5 copies/μl in the deceased fish, and 101.4 to 103.0 copies/μl in the feeding water at various stages from latent infection to onset of disease. The field samples from Huzhou, Zhejiang Province on June 4th and 7th had higher detection rates, 87.5 % and 100 % respectively, corresponding to higher CyHV-2 detected in the aquaculture water. CyHV-2 viral load in cultured waters tends to increase prior to fish death, which provides a new indicator for the prediction of fish diseases. In summary, we have established a unified operational standard for enrichment of CyHV-2 in the aqueous environment by iron flocculation.

Adsorption characteristics and mechanisms of individual and a quinary mixture of heavy metal ions on novel CoFe2O4-BiFeO3 nanosorbents in water

Application of CoFe2O4-BiFeO3 nanocomposites (CFO-BFO NCs) in highly adsorptive removal of heavy metal ions (Pb(II), Co(II), Cu(II), Cd(II) and Zn(II)) by individual and simultanoeous adsorption were investigated for the first time in the present study. The characterization of CFO-BFO NCs were analyzed by using XRD, VSM, SEM, TEM and BET techniques. The CFO-BFO NCs powder consists of characteristic peaks of BFO and CFO without any trace of other crystalline phases; they were uniformly dispersed with a size of about 3–5 nm, much smaller than single – phase CFO (10–25 nm) and BFO (5–10 µm) with the surface area of 84.93 m2/g; remanence and coercivity were 14.33 emu/g, 1.99 emu/g and 195 Oe, respectively, significantly decreased compared to CFO but significantly increased compared to BFO. The single or simultaneous adsorption of a quinary mixture of Pb(II), Co(II), Cu(II), Cd(II) and Zn(II) on CFO-BFO NCs followed the Freundlich isotherm model and the pseudo-second-order kinetic model. Adsorption capacity of single heavy metal ions were in the order Pb(II) > Co(II) > Cu(II) > Cd(II) > Zn(II) while the simultaneous adsorption was in the order Pb(II) > Cu(II) > Co(II) > Zn(II) > Cd(II). The maximum adsorption capacities (qmax) of each ion in the case of simultaneous adsorption were smaller than that for cases of the single adsorption but the total qmax of ions mixture was much higher than the highest qmax of single adsorption. The simultaneous adsorption of heavy metal ions is the competition, the best selectivity is Pb(II) and the strongest competition is Cd(II), the adsorption ability reduces as the charge and radius of interfering cation increase and the ionic strength increases. The regeneration and reuse ability were good, while the adsorption efficiency slightly decreased over three recycles. The adsorption increased slightly as temperature increased. The adsorption process was spontaneous and endothermic. Adsorption of heavy metal ions on CFO-BFO NCs consists of both electrostatic and chemisorption. The applicability for real sample is good. Our results demonstrate that the CFO-BFO NCs is a prospective adsorbent to remove Pb(II), Co(II), Cu(II), Cd(II) and Zn(II) from aqueous environment.

Surface engineered novel cationic surfactants with enhanced surface adsorption for environmental applications

Gemini Cationic Surfactants (GCS) have garnered significant attention due to their distinctive molecular structure, featuring two hydrophilic head groups associated with a hydrophobic spacer. This distinctive configuration enables diverse applications across various fields. Hence, the current study introduces a novel series of GCSs, ethanediyl-1,2-bis[di(2-hydroxypropyl) alkylammonium] dibromide (Cn-C2-Cn[IsoPr(OH)2; n = 9, 12 and 14) and comprehensively explore their properties, highlighting their promising antimicrobial activity. The synthesis of GCSs was validated using 1H NMR and IR spectroscopy. Dynamic Light Scattering was employed to determine the dimensions of Gemini surfactant aggregates in aqueous solutions. Surface tension analysis determined critical concentrations of micelle (CMC), minimum surface area (Amin) and concentration of surface excess (Γmax). Physicochemical properties were assessed through conductivity and surface tension analyses in aqueous solutions. The CMC, Amin and Γmax values decrease as alkyl chain length extends. Surface tension data revealed strong adsorption of GCSs at interfaces. π values (mN/m) ranged from 36.7 (C14C2C14[Iso-Pr(OH)]2) to 45.3 (C9C2C9[Iso-Pr(OH)]2). Conductivity and surface tension measurements further characterized Gemini surfactants in aqueous environments at 298 K. The size of the micelle aggregates varied between C9C2C9[Iso-Pr(OH)]2 (1.2885 nm) and C14C2C14[Iso-Pr(OH)]2 (1.9210 nm), highlighting the impact of chain length on micelle size. Hence, the study highlights significant effect of the chain lengths on Gemini cationic surfactants’ self-assembly in dilute aqueous environments. Antimicrobial tests demonstrated significant activity of Cn-C2-Cn[IsoPr(OH)]2 GCSs at varying concentrations. Antimicrobial tests showed the significant antimicrobial potential of these GCS compounds, suggesting their potential and promising applications in medical, hygiene, environmental sanitation and advanced materials sectors.

Dynamic interactions of negatively charged gold nanoparticles (AuNPs) in aqueous environments with different ionic compositions

This study provides a comprehensive analysis of the interactions between negatively charged gold nanoparticles (Au)144(SRCOO1−)60 and both divalent (Mg2+, Ca2+) and monovalent (Na+, K+) ions in aqueous solution, employing molecular dynamics simulations. The investigation focuses on elucidating the energetics, hydrogen bond patterns and radial distribution of ions surrounding gold nanoparticles. Our results reveal distinct differences in the Coulombic and van der Waals energies between gold nanoparticles and ions, as well as between gold nanoparticles and water, which exert influence on hydrogen bond patterns and lifetimes, as even as ion and water mobility. These findings have important implications for potential applications in nanotechnology and materials science. This research contributes to a deeper understanding of ion-nanoparticle interactions and provides valuable insights for the design and development of new nanomaterials with properties and functionalities.

Magnetic Field Induced Dielectric Polarization to Enhance Raman Detection of Nitrite by NiFe2O4@Ag

AbstractRapid and accurate detection of nitrite in the aqueous environment is extremely important for ecological safety and human health. In this paper, the Raman detection of nitrite by a NiFe2O4@Ag sensor in water is enhanced by an extra magnetic field collaborated with surface plasma. Most importantly, it is demonstrated that the magnetic field enhances the Raman peak intensity through not only the effect of magnetic aggregation but also the magnetic field‐induced dielectric polarization effect. In this way, the NO2− can be detected in a wide linear range from 10−8 to 10−3 mol L−1, and the limit of detection (LOD) can reach as low as 1.25 × 10−9 mol L−1, which is 5.69 times lower than that in the absence of an external magnetic field. Similarly, the sensitivity under the magnetic field is 2.65 times that without the magnetic field. In addition, the sensor also shows superior detection ability to NO2− in real samples. Given the excellent capability of the magnetic field‐enhanced Raman spectra, the reported strategy offers new thoughts on how to enhance the detection ability by an external magnetic field and show the great application potential in real water bodies.

Electrocatalytic degradation of flutamide an anti-prostate cancer drug and its metabolite 4-nitro-3-(trifluoromethyl) aniline using a simple graphite/β-PbO2 electrode

Flutamide is an anti-androgen drug used to treat prostate cancer. It has been determined that this drug exists in aqueous environments at ng/L levels. On the other hand, the environmental impacts of flutamide (FLU) have not yet been determined. This paper reports a simple electrocatalytic convergent-paired strategy for the degradation of FLU and its metabolite 4-nitro-3-(trifluoromethyl) aniline (NTA) using a simple graphite/β-PbO2 anode. The prepared electrode has good electrochemical stability and lifetime (more than 60 h). The results showed that the degradation efficiency of FLU and NTA under optimal conditions (pH 5.0, pollutant concentration 138 ppm and applied current density 4.9 mA/cm2) is 86 and 99 %, respectively. Also, in the solution containing both FLU and NTA with a concentration of 138 ppm of each compound, the degradation efficiency of FLU and NTA is 82 % and 92 %, respectively. Furthermore, we have comprehensively investigated the electrochemical behavior of FLU and NTA and we compared the electrochemical similarities and differences of the drug with its metabolite, and also reported important data such as electrochemical reaction mechanism, pH-potential relationship, and drug absorption/diffusion activity.