Aqueous Environment Research Articles

Near-infrared light-driven lab-on-paper cathodic photoelectrochemical aptasensing for di(2-ethylhexyl)phthalate based on AgInS2/Cu2O/FeOOH photocathode

Di(2-ethylhexyl)phthalate (DEHP) is commonly released from plastics in aqueous environment, which can disrupt endocrine system and cause adverse effects on public health. There is a pressing need to highly sensitive detect DEHP. Herein, a near-infrared (NIR) light-driven lab-on-paper cathodic photoelectrochemical aptasensing platform integrated with AgInS2/Cu2O/FeOOH photocathode and “Y”-like ternary conjugated DNA nanostructure-mediated “ON-OFF” catalytic switching of hemin monomer-to-dimer was established for ultrasensitive DEHP detection. Profiting from the collaborative roles of the effective photosensitization of NIR-response AgInS2 and the fast hole extraction of FeOOH, the NIR light-activated AgInS2/Cu2O/FeOOH photocathode generated a markedly enhanced photocathodic signal. The dual hemin-labelled “Y”-like ternary conjugated DNA nanostructures made the hemin monomers separated in space and they maintained highly active to catalyze in situ generation of electron acceptors (O2). The hemin monomers were relocated in close proximity with the help of target-induced allosteric change of DNA nanostructures, which could spontaneously dimerize into catalytically inactive hemin dimers and fail to mediate electron acceptors generation, resulting in a decreased photocathodic signal. Therefore, the ultrasensitive DEHP detection was realized with a linear response range of 1 pM–500 nM and a detection limit of 0.39 pM. This work rendered a promising prototype to construct powerful paper-based photocathodic aptasensing system for sensitive and accurate screening of DEHP in aqueous environment.

Electronic analysis of n-propyl xanthate complexes with group 12 metals: a theoretical-experimental study.

Xanthates are organic compounds of great interest in coordination chemistry due to their different basic sites, which allow them to form complexes with different coordination modes and geometries. These compounds are relevant in the environment and act as heavy metal collectors in aqueous environments. In this theoretical-experimental work, electronic spectroscopy studies of n-propyl xanthate complexes with group 12 metals were performed. This study verified structural differences in these systems, depending on the environment in which they are inserted. In addition, structural differences were observed when the solid was changed to an n-hexane solution. Thus, it was observed that the complexes assume a mononuclear structure in solution, while they present a polymeric form in the solid phase. The electronic spectra obtained through TD-DFT calculations were compared to those of the previously synthesized complexes. In the final theoretical analysis, the main orbitals involved in these transitions were assigned using population analysis calculations. The synthesis of the complexes was confirmed through infrared (MID and FAR), UV‒Vis, Raman, and NMR-1H spectroscopic analyses. The structures of the mononuclear and polymeric complexes were optimized in vacuum and n-hexane. Under vacuum, DFT levels M06L/6-311 + + G** + LANL2TZ and M06L/def2-TZVP were used for the mononuclear complexes, and M06L/LANL2DZ + LANL2 were used for the polymer complexes. For the calculations of the mononuclear complexes in n-hexane, the same level of theory was used for the solid state. TD-DFT calculations for 300 excited states were performed with the same levels of theory and used the optimized structures of the complexes. Furthermore, population analysis was carried out on all the systems studied. Gaussian 09 software was used for the structure optimization, TD-DFT, and population analysis calculations. GaussSum software was used to evaluate the molecular orbitals and electronic spectra.

Comparison of Sucrose and Trehalose for Protein Stabilization Using Differential Scanning Calorimetry.

The disaccharide trehalose is generally acknowledged as a superior stabilizer of proteins and other biomolecules in aqueous environments. Despite many theories aiming to explain this, the stabilization mechanism is still far from being fully understood. This study compares the stabilizing properties of trehalose with those of the structurally similar disaccharide sucrose. The stability has been evaluated for the two proteins, lysozyme and myoglobin, at both low and high temperatures by determining the glass transition temperature, Tg, and the denaturation temperature, Tden. The results show that the sucrose-containing samples exhibit higher Tden than the corresponding trehalose-containing samples, particularly at low water contents. The better stabilizing effect of sucrose at high temperatures may be explained by the fact that sucrose, to a greater extent, binds directly to the protein surface compared to trehalose. Both sugars show Tden elevation with an increasing sugar-to-protein ratio, which allows for a more complete sugar shell around the protein molecules. Finally, no synergistic effects were found by combining trehalose and sucrose. Conclusively, the exact mechanism of protein stabilization may vary with the temperature, as influenced by temperature-dependent interactions between the protein, sugar, and water. This variability can make trehalose to a superior stabilizer under some conditions and sucrose under others.

Development of a FRET aptasensor based on MoS2-doped Zn-MOF as luminophore for selective detection of cadmium in aqueous solutions.

A robust "on-off" fluorescent aptasensor was developed using nanohybrids of molybdenum sulfide (MoS2) quantum dot (QD)-doped zinc metal-organic frameworks (Zn-MOF) for selective and sensitive detection of cadmium ions (Cd2+) in water. This nanohybrid (MoS2@Zn-MOF), synthesized via "bottle around the ship" methodology, exhibited a high-intensity fluorescence emission centered at 430nm (λEm) (blue) on excitation at 320nm (λEx). Further, the conjugation of this fluorophore to phosphate-modified cadmium aptamer (Cd-2-2) was achieved through carbodiimide reaction. The hybridization of prepared sensing probe (MoS2@Zn-MOF/Cd-2-2 aptamer) was done with dabcyl-conjugated complementary DNA (cDNA), acting as energy donor-acceptor pair in the fluorescence resonance energy transfer (FRET) system. This hybridizationcauses the fluorescence quenching of the nanohybrid. In the presence of Cd2+, the aptamer from the fabricated nano-biosensing probe binds to these ions, resulting in release of dabcyl-cDNA oligomer. This release of dabcyl-cDNA oligomer from the sensing probes restores the fluorescence of the nanohybrid. Under optimized conditions (sensing probe/dabcyl-cDNA ratio 1/7, pH 7.4, and temp 28°C), the sensing probe showed a fast response time of 1min. The fluorescence intensity of the nanohybrid can be utilizedto determine the concentration of Cd2+. The proposed aptasensor achieved highly sensitive detection of Cd2+ with a limit of detection (LOD) of 0.24ppb over the range of 1 × 10-9 to 1 × 10-4M along with minimal effects of interferences (e.g., Hg2+, Pb2+, and Zn2+) and good reproducibility. The designed aptasensor based on MoS2@Zn-MOF nanofluorophore offers a highly sensitive and selective approach for rapid screening of metal ions in aqueous environments.

Elucidating deposition process of calcium carbonate and mechanical properties of precipitation via molecular dynamics simulation

Brittle cracking is a critical issue affecting the load bearing capacity and service life of concrete. Microbially induced calcium carbonate precipitation can heal concrete cracks, but the relation between its microscopic morphology and macroscopic mechanical properties remains poorly understood. This study employs molecular dynamics simulations to investigate the deposition processes of calcite and aragonite unit cells on calcium carbonate substrates. The deposition process of a single unit cell can be divided into two stages: collision rebound and adsorption. The deposited unit cells combine to form amorphous calcium carbonate. Local disordering of substrate upper-surface caused by unit cell collision reduces the tensile strength of the substrates, while the ductility of amorphous precipitations enhances its failure strain. The deposition velocity significantly impacts the mechanical properties of the precipitations. At higher temperature, greater molecular mobility enhances cohesive strength within the precipitations. Aqueous environments can weaken the collisional impacts of deposited unit cells on the substrate. Matching the substrate and deposited unit cell types facilitates ordered structures and strengthens precipitations. This work deepens the understanding of deposition process of calcium carbonate on the substrate and the mechanical properties of precipitations.

Bio‐Inspired Crystalline Core‐Shell Guanine Spherulites

AbstractSpherical particles with diameters within the wavelength of visible light, known as spherulites, manipulate light uniquely due to their spatial organization and their structural birefringence. Most of the known crystalline spherulites are branched, and composed of metals, alloys, and semi‐crystalline polymers. Recently, a different spherulite architecture was discovered in the vision systems of decapod crustaceans ‐ core‐shell spherulites composed of highly birefringent (Δn ∼ 30%) organic single‐crystal platelets, with exceptional optical properties. These metastructures, which efficiently scatter light even in dense aqueous environments, have no synthetic equivalence and serve as a natural proof‐of‐concept as well as synthetic inspiration for thin scattering media. Here, we present the synthesis of core‐shell spherulites composed of guanine crystal platelets (Δn ∼ 25%) in a two‐step emulsification process in which we use a water/oil/water emulsion and induced pH changes to promote interfacial crystallization. Carboxylic acids neutralize the dissolved guanine salts to form spherulites composed of single, radially stacked, β‐guanine platelets, which are oriented tangentially to the spherulite surface. Using Mie theory calculations and forward scattering measurements from single spherulites, we find that due to the single‐crystal properties and orientation, the synthetic spherulites possess a high tangential refractive index, similarly to biogenic particles.This article is protected by copyright. All rights reserved

Effects of Adding Sorghum Procyanidins on the Structure, Molecular Interactions, and Thermal Properties of Agar-Glycerol-Gelatin Films

Films made with blends of agar and gelatin are usually unstable in aqueous environments and susceptible to temperature, so modifying these films with the addition of compatible compounds is necessary to improve their structural stability, properties, and potential uses. This work determined the effects of adding sorghum procyanidins on the structure, molecular interactions and thermal properties of agar-glycerol-gelatin films. Films were prepared by solution cast method and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and computational methods. Adding sorghum procyanidins to agar-gelatin films plasticized with glycerol produced significant modifications compared to control films. They contributed to the amorphous character and roughness of these films and the film’s microstructure, reducing weight loss and enhancing thermal stability. The predominant interactions among the film components were hydrogen bonds, van der Waals, and [Formula: see text]–[Formula: see text] interactions.

Homogenous Oxidizing Oligomerization Coupled with Coagulation for Water Purification

Natural manganese oxides could induce the intermolecular coupling reactions among small-molecule organics in aqueous environments, which is one of the fundamental processes contributing to natural humification. These processes could be simulated to design novel advanced oxidation technology for water purification. In this study, periodate (PI) was selected as the supplementary electron-acceptor for colloidal manganese oxides (Mn(IV)aq) to remove phenolic contaminants from water. By introducing polyferric sulfate (PFS) into the Mn(IV)aq/PI system and exploiting the flocculation potential of Mn(IV)aq, a post-coagulation process was triggered to eliminate soluble manganese after oxidation. Under acidic conditions, periodate exists in the H4IO6− form as an octahedral oxyacid capable of coordinating with Mn(IV)aq to form bidentate complexes or oligomers (Mn(IV)-PI*) as reactive oxidants. The Mn(IV)-PI* complex could induce cross-coupling process between phenolic contaminants, resulting in the formation of oligomerized products ranging from dimers to hexamers. These oligomerized products participate in the coagulation process and become stored within the nascent floc due to their catenulate nature and strong hydrophobicity. Through coordination between Mn(IV)aq and H4IO6−, residual periodate is firmly connected with manganese oxides in the floc after coagulation and could be simultaneously separated from the aqueous phase. This study achieves oxidizing oligomerization through a homogeneous process under mild conditions without additional energy input or heterogeneous catalyst preparation. Compared to traditional mineralization-driven oxidation techniques, the proposed novel cascade processes realize transformation, convergence, and separation of phenolic contaminants with high oxidant utilization efficiency for low-carbon purification.

Disentangling Acid-Base Chemistry through Blue Shifting Hydrogen Bond Contributions.

The blue shifting of vibrational frequencies in hydrogen bonded molecules, as observed in aqueous environments, has been attributed to local partial charge transfer from solvation. Here, we extrapolate the blue shift model to the stronger ionic interactions between hydrogen bond acceptors associated with protonation through augmented pH levels and competitive interactions with counter ion pairing. The chemical model we utilize in this work is the aqueous pyridine-pyridinium equilibrium to characterize the blue shifts observed in the pyridinium chloride ionic system. The observed agreement between observed experimental and calculated spectral shifts shows that the blue shifting model can be extrapolated to stronger interactions and accurately describe the nature of the hydrogen bond.

Conformations of a highly expressed Z19 α-zein studied with AlphaFold2 and MD simulations.

α-zeins are amphiphilic maize seed storage proteins with material properties suitable for a multitude of applications e.g., in renewable plastics, foods, therapeutics and additive manufacturing (3D-printing). To exploit their full potential, molecular-level insights are essential. The difficulties in experimental atomic-resolution characterization of α-zeins have resulted in a diversity of published molecular models. However, deep-learning α-zein models are largely unexplored. Therefore, this work studies an AlphaFold2 (AF2) model of a highly expressed α-zein using molecular dynamics (MD) simulations. The sequence of the α-zein cZ19C2 gave a loosely packed AF2 model with 7 α-helical segments connected by turns/loops. Compact tertiary structure was limited to a C-terminal bundle of three α-helices, each showing notable agreement with a published consensus sequence. Aiming to chart possible α-zein conformations in practically relevant solvents, rather than the native solid-state, the AF2 model was subjected to MD simulations in water/ethanol mixtures with varying ethanol concentrations. Despite giving structurally diverse endpoints, the simulations showed several patterns: In water and low ethanol concentrations, the model rapidly formed compact globular structures, largely preserving the C-terminal bundle. At ≥ 50 mol% ethanol, extended conformations prevailed, consistent with previous SAXS studies. Tertiary structure was partially stabilized in water and low ethanol concentrations, but was disrupted in ≥ 50 mol% ethanol. Aggregated results indicated minor increases in helicity with ethanol concentration. β-sheet content was consistently low (∼1%) across all conditions. Beyond structural dynamics, the rapid formation of branched α-zein aggregates in aqueous environments was highlighted. Furthermore, aqueous simulations revealed favorable interactions between the protein and the crosslinking agent glycidyl methacrylate (GMA). The proximity of GMA epoxide carbons and side chain hydroxyl oxygens simultaneously suggested accessible reactive sites in compact α-zein conformations and pre-reaction geometries for methacrylation. The findings may assist in expanding the applications of these technologically significant proteins, e.g., by guiding chemical modifications.

Flexible porous nanofibrous sponge with antioxidant and antibacterial characteristics for promoting diabetic wound healing

Excessive reactive oxygen species (ROS) and bacterial burden delay diabetic wound healing. Although antioxidants and antibacterials have the potential to mitigate excessive ROS and bacterial burden, their efficacy is compromised by the presence of abundant exudate. In this study, a porous chitosan/polyvinyl alcohol nanofibrous sponge immobilized with protocatechualdehyde (CPNS-PA) is developed as a flexible dressing. The CPNS-PA exhibits favorable liquid management ability, high liquid absorption capacity (3867.73 %), superior air permeability (281.1 mm/s), and great compressive recovery at a strain of 50 %. Immobilizing protocatechualdehyde endows CPNS-PA with improved antioxidant and antibacterial properties. Besides, to enhance the stability of CPNS-PA in an aqueous environment, heat treatment is employed instead of toxic chemical agents, thereby preserving its excellent cytocompatibility. The experiments conducted on a diabetic mouse wound model demonstrate that CPNS-PA effectively promotes diabetic wound healing, indicating its promising potential for clinical applications in diabetic wound healing.

From waste to treasure: Synthesis of Ag3PO4/TiO2/r-SiC composite photocatalysts with efficient photocatalytic performance using waste photovoltaic silicon wafers

The conversion of low-value waste into high-value-added photocatalysts for pollution removal is considered a promising approach for waste utilization. In this work, regenerated SiC (r-SiC) nanowires were synthesized using waste photovoltaic silicon wafers through a mechanochemical-carbothermal reduction method. The prepared filamentary structure of r-SiC nanowires as a substrate for an Ag3PO4/TiO2/r-SiC (APO/TIO/r-SiC) ternary photocatalyst was prepared by immobilizing TiO2 and Ag3PO4 on r-SiC nanowires. The 30%APO/TIO/r-SiC (loaded with 30 wt%Ag3PO4) achieved more than 90% degradation rate for six organic dyes, and 80% for tetracycline (TC) within 15 min, respectively. The loading of TiO2 and Ag3PO4 improved the adsorption of molecular oxygen in the aqueous environment, which facilitated the generation of reactive oxygen species and enhanced the photocatalytic performance of 30%APO/TIO/r-SiC. The Z and II dual-scheme electron transfer mechanism for 30%APO/TIO/r-SiC was demonstrated to promote effectively carrier separation. Three potential pathways of RhB degradation were proposed, and the disruption of the conjugated structure (chromophore) was the main cause of RhB degradation. The radical quenching experiments revealed that the degradation process was more significantly influenced by •O2- and •OH than h+. The research proposed a promising 'win-win' treatment approach for waste photovoltaic wafers and delved into the photocatalytic performance and enhancement mechanism of SiC-based composite catalysts.

Probing Alzheimer's pathology: Exploring the next generation of FDDNP analogues for amyloid β detection

Fluorescent probes are a powerful tool for imaging amyloid β (Aβ) plaques, the hallmark of Alzheimer’s disease (AD). Herein, we report the synthesis and comprehensive characterization of 21 novel probes as well as their optical properties and binding affinities to Aβ fibrils. One of these dyes, 1Ae, exhibited several improvements over FDDNP, an established biomarker for Aβ- and Tau-aggregates. First, 1Ae had large Stokes shifts (138–213 nm) in various solvents, thereby reducing self-absorption. With a high quantum yield ratio (φ(dichloromethane/methanol) = 104), 1Ae also ensures minimal background emission in aqueous environments and high sensitivity. In addition, compound 1Ae exhibited low micromolar binding affinity to Aβ fibrils in vitro (Kd = 1.603 µM), while increasing fluorescence emission (106-fold) compared to emission in buffer alone. Importantly, the selective binding of 1Ae to Aβ1–42 fibrils was confirmed by an in cellulo assay, supported by ex vivo fluorescence microscopy of 1Ae on postmortem AD brain sections, allowing unequivocal identification of Aβ plaques. The intermolecular interactions of fluorophores with Aβ were elucidated by docking studies and molecular dynamics simulations. Density functional theory calculations revealed the unique photophysics of these rod-shaped fluorophores, with a twisted intramolecular charge transfer (TICT) excited state. These results provide valuable insights into the future application of such probes as potential diagnostic tools for AD in vitro and ex vivo such as determination of Aβ1–42 in cerebrospinal fluid or blood.

Radioiodine‐Mediated Transition Metal Valence Conversion for Enhanced Chemodynamic Therapy

AbstractChemodynamic therapy (CDT) presents promise as a cancer treatment method, but its efficacy faces challenges due to the inefficient Fenton catalytic reaction, where the transition metals' conversion from high to low valence states acts as the rate‐limiting step. Here, a strategy employing radioiodine is introduced to facilitate the valence conversion of transition metals for CDT enhancement. Iron‐based metal‐organic framework (MOF) nanoparticles (NPs) are synthesized labeled with radioiodine‐125 (125I), referred to as 125I‐MIL‐88B(Fe) NPs. These NPs possess a porous structure capable of concentrating and catalyzing H2O2 to generate highly toxic hydroxyl radicals (·OH). Furthermore, 125I can continuously produce hydrated electrons (eaq−) in aqueous environments, promoting the conversion of Fe3+/Fe2+ to boost ·OH production. In vitro and in vivo experiments validate the enhanced CDT effect on pancreatic cancer, driven by the reactive oxygen species (ROS)/mitogen‐activated protein kinase (MAPK)/p53 pathway‐mediated cell apoptosis. The radioiodine‐mediated electron‐supplying strategy not only amplifies the effectiveness of CDT but also unlocks new potential applications for radionuclides.

Water‐in‐Polymer Salt Electrolyte for Long‐Life Rechargeable Aqueous Zinc‐Lignin Battery

Zinc metal batteries (ZnBs) are poised as the next‐generation energy storage solution, complementing lithium‐ion batteries, thanks to their cost‐effectiveness and safety advantages. These benefits originate from the abundance of zinc and its compatibility with non‐flammable aqueous electrolytes. However, the inherent instability of zinc in aqueous environments, manifested through hydrogen evolution reactions (HER) and dendritic growth, has hindered commercialization due to poor cycling stability. Enter potassium polyacrylate (PAAK)‐based water‐in‐polymer salt electrolyte (WiPSE), a novel variant of water‐in‐salt electrolytes (WiSE), designed to mitigate side reactions associated with water redox processes, thereby enhancing the cyclic stability of ZnBs. In this study, WiPSE was employed in ZnBs featuring lignin and carbon composites as cathode materials. Our research highlights the crucial function of acrylate groups from WiPSE in stabilizing the ionic flux on the surface of the Zn electrode. This stabilization promotes the parallel deposition of Zn along the (002) plane, resulting in a significant reduction in dendritic growth. Notably, our sustainable Zn‐lignin battery showcases remarkable cyclic stability, retaining 80% of its initial capacity after 8000 cycles at a high current rate (1 A g−1) and maintaining over 75% capacity retention up to 2000 cycles at a low current rate (0.2 A g−1). This study showcases the practical application of WiPSE for the development of low‐cost, dendrite‐free, and scalable ZnBs.

An AIE dynamic a highly selective and expeditious benzothiazole-pyrazine based colorimetric chemosensor for Ni2+and fluorogenic chemosensor for Cu2+ and Al3+ detection

Considerable research focus has been devoted to the advancement of single-component sensors that can identify several analytes. In this regard, a complex chemosensor called BPA was created by building an imine link between benzothiazole and pyrazine. On the flexible imine link, the nitrogen atoms with lone pair electrons were arranged as possible coordination sites to enable changes in molecular configurations and charge transfer. In the aqueous acetonitrile environment, BPA displayed the discriminative identification of Ni2+ by a chromogenic response (color transition from colorless to yellow) and a fluorescence “decreasing” response for Cu2+ via ligand–metal charge transfer. Additionally, BPA exhibited recognition of Al3+ through a “turn-on” fluorogenic response facilitated by the chelation-enhanced fluorescence effect. The detection limits for Ni2+, Al3+, and Cu2+ were remarkably low, measuring 5.19 nM, 16 nM, and 214 nM, respectively. A 1:1 binding stoichiometry and precise complex modes between BPA and the target metal ions were successfully determined using extensive investigations, which encompassed the utilization of Job's plot, mass spectra, NMR, and DFT analysis. The deduced coordination mechanisms were corroborated by computational and experimental methodologies. BPA's potential practical uses were demonstrated by subsequently evaluating its ability to identify Ni2+, Al3+, and Cu2+ in actual water samples and validating its performance on-site using test strips.

Bifunctional octadentate pseudopeptides as Zirconium-89 chelators for immuno-PET applications

BackgroundPositron emission tomography (PET) is a highly sensitive method that provides fine resolution images, useful in the field of clinical diagnostics. In this context, Zirconium-89 (89Zr)-based imaging agents have represented a great challenge in molecular imaging with immuno-PET, which employs antibodies (mAbs) as biological vectors. Indeed, immuno-PET requires radionuclides that can be attached to the mAb to provide stable in vivo conjugates, and for this purpose, the radioactive element should have a decay half-life compatible with the time needed for the biodistribution of the immunoglobulin. In this regard, 89Zr is an ideal radioisotope for immuno-PET because its half-life perfectly matches the in vivo pharmacokinetics of mAbs.ResultsThe main objective of this work was the design and synthesis of a series of bifunctional octadentate pseudopeptides able to generate stable 89Zr complexes. To achieve this, here we investigated hydroxamate, N-methylhydroxamate and catecholate chelating moieties in complexing radioactive zirconium. N-methylhydroxamate proved to be the most effective 89Zr-chelating group. Furthermore, the increased flexibility and hydrophilicity obtained by using polyoxyethylene groups spacing the hydroxamate units led to chelators capable of rapidly forming (15 min) stable and water-soluble complexes with 89Zr under mild reaction conditions (aqueous environment, room temperature, and physiological pH) that are mandatory for complexation reactions involving biomolecules. Additionally, we report challenge experiments with the competitor ligand EDTA and metal ions such as Fe3+, Zn2+ and Cu2+. In all examined conditions, the chelators demonstrated stability against transmetallation. Finally, a maleimide moiety was introduced to apply one of the most promising ligands in bioconjugation reactions through Thiol-Michael chemistry.ConclusionCombining solid phase and solution synthesis techniques, we identified novel 89Zr-chelating molecules with a peptide scaffold. The adopted chemical design allowed modulation of molecular flexibility, hydrophilicity, as well as the decoration with different zirconium chelating groups. Best results in terms of 89Zr-chelating properties were achieved with the N-methyl hydroxamate moiety. The Zirconium complexes obtained with the most effective compounds were water-soluble, stable to transmetallation, and resistant to peptidases for at least 6 days. Further studies are needed to assess the potential of this novel class of molecules as Zirconium-chelating agents for in vivo applications.

Engineering MOF-derived 2D NPC-TiO2 nanotablet/3D marigold-like ZnIn2S4/CdS nanoparticles dual Z-scheme heterojunction with excellent photoelectric performance: A novel material for sensitive and facile photoelectrochemical sensing detection of mercury ions in aqueous environments by ion-exchange sensing strategy

Herein, a new NH2-MIL-125-derived 2D nitrogen-doped porous carbon-titanium dioxide (NPC-TiO2) nanotablet/3D marigold-like ZnIn2S4/CdS nanoparticles (NPs) dual Z-scheme heterojunction was first exploited for photoelectrochemical (PEC) measurement of mercury ions (Hg2+). Taking NH2-MIL-125 as precursor, the 2D NPC-TiO2 nanotablet was prepared by calcination. The 3D marigold-like ZnIn2S4 and CdS NPs were synthesized by hydrothermal method and aqueous synthesis way, respectively. The acquired NPC-TiO2, ZnIn2S4 and CdS were sequentially modified on the indium tin oxide (ITO) electrode to form the PEC sensing interface by layer-by-layer assembly. Due to the matched band-edge levels, and strong light-harvesting ability, the given heterostructure on ITO electrode generated a large photocurrent. Importantly, it was found that 2D NPC-TiO2 nanotablet/3D marigold-like ZnIn2S4/CdS NPs dual Z-scheme heterojunction could show specifically increased photocurrent signal towards to Hg2+ by employing CdS NPs as Hg2+-recognition probe with selective Cd-to-Hg ion-exchange, resulting from the in-situ formation of the new quaternary NPC-TiO2/ZnIn2S4/CdS/HgS heterostructure to further facilitate the spatial transmission and separation of charges. As a result, Hg2+ was highly sensitively detected with a low detection limit of 20 fM. This PEC sensor was also verified by evaluating Hg2+ in tap water, river water and lake water, demonstrating great application prospect for environment pollutant measurement.

Advanced g-C3N4 and bimetallic FeNi-BTC integration with carbon quantum dots for removal of microplastics and antibiotics in aqueous environments

In this study, a novel approach was undertaken by integrating the photocatalyst graphite carbon nitride (g-C3N4) with FeNi-BTC (BTC: Benzene-1,3,5-tricarboxylic acid) and carbon quantum dots (CQDs) to enhance the interaction between semiconductors. The g-C3N4/CQD/FeNi-BTC material was synthesized using an environmentally friendly method that eschews the use of harmful solvents, using a combination of hydrothermal and microwave methods. The resulting material boasts a large pore volume (1.192 cm3g–1), a high surface area (1090 m2g–1), a small particle size (40–60 nm), and the capability to absorb visible light (2.27–2.52 eV). This material demonstrates remarkable efficiency in adsorbing microplastics, including polystyrene and polyethylene terephthalate (PET), at a concentration of 1200 mg L–1, achieving nearly 100% efficiency in just 45 minutes. Additionally, the g-C3N4/CQD/FeNi-BTC material shows significant effectiveness in degrading tetracycline, with an efficiency of 98.28% after 90 minutes of exposure to visible light irradiation. The study extensively explores factors that influence the pollutant treatment process, including time, concentration, pH value, temperature and the water source. The process of adsorbing MP on g-C3N4/CQD/Fe8Ni2BTC material is mainly physical adsorption, following pseudo-second-order reaction kinetics, endothermic reaction (ΔH > 0), and the adsorption process occurs spontaneously (ΔG < 0). This comprehensive approach provides valuable insights into the potential of the g-C3N4/CQD/FeNi-BTC material for treating pollutants in a range of aquatic environments, highlighting its versatility and effectiveness in environmental remediation.

Enhanced Hydrogen Evolution in Porous and Hybrid g‐C3N4/Pt‐PVDF Electrospun Membranes via Piezoelectricity from Water Flow Energy

AbstractInspired from seaweed swayed by waves, the enhanced hydrogen evolution is realized in porous and hybrid g‐C3N4/Pt‐PVDF electrospun membranes via piezoelectricity from water flow energy. The membranes are fabricated by dispersing g‐C3N4/Pt into the mixed solution of PVDF and PEO, followed by electrospinning and selective removal of PEO. By changing the PEO amount, the pore size in nanofibers is adjusted. Due to the hydrogen bonding between g‐C3N4/Pt and PVDF, the β phase of PVDF is increased, beneficial for the piezoelectricity performance. When the electrospun membranes are exposed to water flow, an additional potential field is triggered due to the deformation of PVDF. It not only eases the photogeneration of charge carriers from g‐C3N4/Pt but also hinders their recombination. The prolonged lifetime significantly improves the photocatalytic water splitting of g‐C3N4/Pt under visible light. The hydrogen evolution in the electrospun membranes (PVDF to PEO = 4:1) is profoundly improved to 9 278 µmol h−1 g−1, almost doubled to the pure g‐C3N4/Pt nanosheets (5 220 µmol h−1 g−1). Therefore, the seaweed‐inspired electrospun membrane is a promising strategy for the efficiently photocatalytic water splitting via g‐C3N4 in an aqueous environment, such as a natural sea and lake, by the piezoelectricity gained from the water flow energy.