Sustainable nanogold-cellulose composites: Green synthesis, emerging applications and future aspects.

Green synthesis of caffeine-catalyzed citric acid-PPG/PEG crosslinked alginate hydrogel scaffolds for prospective biomedical applications.

The claystone in the Guide area of the Qaidam Basin on the northeastern margin of the Qinghai-Xizang Plateau contains lithium resources. This paper adopts geochemical and isotopic geochemical approaches to analyze the paleoenvironment, tectonic setting, sediment provenance, weathering processes, and lithium sources of the lithium-bearing claystones in the study area, and summarizes the genetic mechanisms of the lithium-bearing claystones. The results indicate that the claystone is dominated by illite and chlorite in mineral composition, with lithium primarily hosted in illite and kaolinite. The paleo-sedimentary aqueous conditions of the claystone correspond to a weakly oxidizing-weakly reducing, brackish water environment, under a semi-arid to semi-humid paleoclimate. Meanwhile, weakly oxidizing-weakly reducing, freshwater, and humid sedimentary environments are more favorable for the formation of lithium-bearing minerals, as evidenced by the highest lithium content in the clay. The source rocks of lithium-bearing clays in the study area were subject to the tectonic setting of the island arc-continental margin transition. Their provenance is dominated by felsic igneous rocks, with minor contributions from intermediate igneous rocks and recycled sedimentary materials. Weathering conditions of the lithium-bearing claystones in the study area indicate that their source rocks experienced weak to moderate weathering, and a certain degree of potassium metasomatism may have occurred during diagenesis. Lithium isotope analyses reveal that lithium in the clays is primarily derived from lithium supplied by sedimentary-stage water bodies and deep-seated hydrothermal fluids. Lithium isotope analysis shows that the δ 7 Li values of lithium in the clay range from 3.67‰ to 8.27‰, with an average of 5.7‰, it indicates that the lithium in the clay of the study area may originate from deep hydrothermal fluids and sedimentary detrital materials.

Complex molecules and simple alkanes pose distinct challenges for catalyst-controlled carbon-hydrogen (C-H) functionalizations. Whereas densely functionalized scaffolds require precise targeting among multiple reactive sites while tolerating sensitive functionalities, unactivated substrates that lack directing groups require selective activation of exceptionally inert, nearly identical C-H bonds. In this work, we addressed both challenges by repurposing a classic chiral auxiliary into a unified, selective, and predictable C-H amination platform mediated by silver catalysis and chiral sulfur(VI) nitrene precursors. This system enables stereodivergent, late-stage aminations of activated C-H bonds with broad functional group tolerance and compatibility with aqueous conditions while also mediating mild, selective aminations of chemical feedstocks. The sulfur(VI) motif functions as a modular, stereodefined, and medicinally relevant synthetic linchpin for rapid library diversification, enabling both target- and diversity-oriented synthesis.

Oxime ligation, a chemoselective coupling between carbonyl compounds and aminooxy groups, enables conjugation under mild and aqueous conditions. Here, we integrate this reaction with degradable polymers through a one-pot synthesis of aminooxy-functionalized poly(ε-caprolactone) (PCL) oligomers. The bifunctional initiator 6-(tert-butyloxycarbonylaminooxy)-1-hexanol was employed for simultaneous ε-caprolactone ring-opening polymerization and in situ Boc-deprotection catalyzed by methanesulfonic acid (MSA). Optimized conditions afforded >95% conversion for both reactions, while maintaining well-defined oligomer structures (DP = 5-20). The resulting NH3+-O-PCL oligomers underwent rapid and efficient oxime ligation with a diverse set of aldehydes and ketones, achieving >90% conversion within 1-2 h at room temperature. Reactions proceeded effectively even in mixed aqueous solvents (H2O/MeOH/CHCl3 = 1:3:1), for example, with the reducing ends of glucose and xylose. This work establishes a straightforward, water-tolerant synthetic platform for preparing "click-ready" degradable polymers, enabling broad integration with biobased and functional substrates.

To date, the application of chiral covalent organic frameworks (CCOFs) as membranes has encountered considerable challenges in attaining high enantioselectivity. In this study, a pair of charged CCOFs, constructed from pyridinium units serving as the framework linkages, was synthesized via a bottom-up synthetic strategy. The incorporation of these irreversible bonds confers substantial stability, particularly under aqueous conditions. These porous chiral materials were subsequently incorporated into a polytetrafluoroethylene membrane, which functioned as the supporting substrate for membrane separation. The resulting membrane exhibited pronounced enantioselectivity toward mandelic acid, tryptophan, and phenylalanine. Enantioseparation analyses revealed that the (S)-CCOF possessed a strong affinity for l-enantiomers, facilitated by multiple intermolecular interactions. Notably, the ionic-pairing effect enhanced the retention of l-enantiomers within the membrane's cavity channels, thereby allowing d-enantiomers to permeate more readily through the porous structure. This separation strategy achieved a maximum enantiomeric excess of 96.2 ± 0.5%. Furthermore, the membrane demonstrated satisfactory reproducibility. In brief, these findings underscore the considerable potential of charged CCOFs to enhance functional performance in membrane-based enantioseparation processes.

In this study, we discovered and characterized efficient aqueous ethyl-ester synthase EsRP3 with high catalytic activity toward medium-chain and aromatic acids. Under aqueous ethanol conditions (2 mol/L ethanol), EsRP3 reached maximal conversions of 36.2% for hexanoic acid (5 mmol/L), 77.6% for octanoic acid (25 mmol/L), and 50.7% for 3-phenylpropionic acid (25 mmol/L) and remained highly active from pH 3 to 6. Protonation states of His203 (binding) and His307 (catalysis) may modulate the pH-dependent catalytic efficiency. Combined molecular dynamics, electrostatic potential analysis, and site-directed mutagenesis indicated that lid-domain flexibility, a positively charged active-site environment, and strong fatty-acid binding contribute to the high aqueous esterification activity of EsRP3. Consistently, the Q209L mutant further enhanced catalytic activity likely by increasing lid-domain flexibility. For stability, mutational analysis revealed that internal hydrogen-bond networks play a critical role in thermal robustness. Overall, this study provides mechanistic insights into the catalytic efficiency and stability of aqueous ester synthases and may contribute to their engineering and potential applications in the food, chemical, and pharmaceutical industries.

Aqueous potassium-ion batteries have emerged as a promising energy storage technology by combining the intrinsic safety of aqueous electrolytes with the high natural abundance of potassium. However, the narrow electrochemical stability window of water and the limited availability of suitable cathode and anode materials impose critical challenges on achieving high energy density and long-term cycling stability. In recent years, substantial progress has been achieved through electrolyte engineering strategies, which effectively suppress water activity, expand the operational voltage window, and stabilize electrode-electrolyte interfaces. On the cathode side, advances in materials such as Prussian blue analogs, transition-metal oxides, and polyanionic compounds have significantly improved structural robustness and K diffusion kinetics. On the anode side, increasing attention has been devoted to interfacial regulation, kinetic compatibility, and mechanical stability under aqueous conditions. Importantly, emerging insights into electrolyte-material interactions reveal that interfacial chemistry plays a decisive role in governing the reversibility and durability of aqueous potassium-ion batteries. This review systematically summarizes recent progress in electrolytes, cathode materials, and anode materials for aqueous potassium-ion batteries. It highlights the remaining challenges and future perspectives toward high-energy-density, durable, and practically viable aqueous potassium-ion batteries.

Recent studies have demonstrated that enzymatic modification of flavonoids, including acylation and polymerisation, can enhance the functional properties of phenolic compounds. However, structurally rigid flavonoids such as quercetin and hesperidin remain challenging substrates for enzymatic transformation due to steric constraints and low solubility. The aim of this study was to address these structural limitations through a systematic screening of enzymatic strategies and reaction conditions using lipase-catalysed acylation and laccase-mediated polymerisation. Acylation reactions were performed using different lipases, solvents, acyl donors, and substrate-to-acylating agent ratios, while polymerisation was evaluated using fungal laccases under mild aqueous conditions. One acylated derivative of quercetin and three acylated derivatives of hesperidin were successfully obtained, achieving conversion yields ranging from 8 to 30%, depending on flavonoid structure and reaction conditions. In addition, two polymerised products derived from quercetin and hesperidin were detected and structurally identified by UPLC/MS. Acylated flavonoids exhibited enhanced antioxidant activity, as determined by DPPH and β-carotene–linoleic acid assays, as well as improved solubility compared to their native counterparts. Overall, these results highlight the potential of enzymatic acylation as an effective strategy to improve the functional properties of structurally complex flavonoids, while laccase-mediated polymerisation provides complementary insights into their structural diversification.

In this research we report the concept and strategy of electrolyte covalent organic frameworks for high-rate low-activation-energy potassium ion conduction. One-pot polymerization of monomers with oligo(ethylene oxide) chains of different lengths creates crystalline porous electrolyte frameworks with discrete electrolyte interfaces in pores. Integration of potassium salts to the pores develops potassium ion-electrolyte networks, offering pathways for potassium ion transport. Notably, the frameworks with well-developed electrolyte interfaces improve ion conductivity, which is not a simple numeric summation of electrolyte chains but shows an exponential correlation. The materials operate over temperatures from 40°C to 190°C under anhydrous conditions and achieve an ion conductivity as high as 3.2 × 10-3 S cm-1 with a low activation energy of 0.2eV. Notably, under humid conditions, the conductivity further increases to 2.1 × 10-1 S cm-1 with an activation energy of only 0.04eV, suggesting a frictionless ion conduction. Remarkably, potassium ion batteries show a stable and wide voltage window of -6 - 6V, with a high potassium ion transference number of 0.76. Our results pave a way to exceptional potassium ion conduction through molecular design of electrolyte frameworks and show their promise for various types of energy storages under solid-state and aqueous conditions.

The development of DNA-encoded library (DEL) technology is contingent upon robust and DNA-compatible reactions to expand accessible chemical space. Tandem transformations, which combine functional group interconversion and scaffold construction in one step, are particularly attractive for streamlining on-DNA synthesis. Herein, we report a copper-mediated tandem reaction conducted under mild, aqueous conditions that enables the in situ reduction of nitro groups followed by reductive amination with aldehydes. This DNA-compatible protocol efficiently furnishes secondary amines directly from nitro substrates, circumventing the need for prereduction. Moreover, the methodology can be extended to o-nitroaniline derivatives, providing efficient one-pot access to benzimidazole scaffolds through tandem nitro reduction and cyclization with aldehydes. Compared to conventional stepwise sequences requiring isolated intermediates, this strategy provides a more streamlined and atom-economical route for constructing privileged pharmacophores directly on DNA.

Reactive aldehyde metabolites are commonly viewed as drivers of nonspecific protein damage and stochastic cross-linking. Here, we show that cooperative aldehyde chemistry can generate multicomponent, mass-consistent electrophilic intermediates in water with strong lysine bias and site selectivity. Specifically, malondialdehyde (MDA) couples with monoaldehydes (e.g., acetaldehyde and benzaldehyde) to form a cooperative intermediate that channels reactivity toward lysine, yielding chemically stable dihydropyridine (DHP) adducts under aqueous conditions. Across peptides, purified proteins, and complex lysates, this pathway produces nonrandom, lysine-selective labeling. Comparison with NHS-ester chemoproteomic data sets suggests a distinct selectivity regime: whereas NHS acylation broadly tracks nucleophile accessibility with weak context dependence, cooperative MDA-monoaldehyde chemistry preferentially labels lysines in acidic microenvironments, consistent with an electrostatically influenced association-and-capture model that promotes productive cyclization to stable DHP adducts. Finally, electronic tuning of the DHP scaffold affords red-shifted emission compatible with live-cell imaging. Together, these results establish a tunable cooperative aldehyde platform that expands selective lysine bioconjugation chemistry and enables proteome-scale mapping of lysine microenvironment reactivity not captured by conventional acylating reagents.

This study computationally investigates the formation of Si ← N dative tetrel bonds between anionic pentacoordinated bis(catecholato)silicate frameworks and a series of pyridine derivatives under aqueous conditions. Despite the silicon center being embedded within a globally anionic environment, it exhibits a pronounced local electronic anisotropy along the axial Si-O bond extension, giving rise to an electron-deficient σ-hole capable of interacting with nitrogen lone pairs. A systematic set of 27 dimers was examined by varying substituents on both the pyridine donor and the catecholate ligands. The calculated interaction energies span from -67.3 to -148.1 kJ mol-1, indicating the formation of energetically favorable donor-acceptor interactions that persist even after accounting for substantial monomer deformation. Analysis of the electron density redistribution accompanying complex formation reveals that the Si ← N contact occupies an intermediate regime between weak noncovalent interactions and classical covalent bonding, consistent with a closed-shell dative interaction dominated by directionality and orbital alignment. The interaction strength is found to be highly sensitive to remote electronic substitution, with stronger nitrogen donors and more electron-withdrawing catecholate substituents enhancing the electrophilic character of the silicon center. Overall, these results show that local electronic features can dominate over formal molecular charge, enabling tunable dative tetrel bonding in hypercoordinate anionic silicon systems.

Two-dimensional (2D) nanomaterials have attracted considerable attention across diverse research fields owing to their unique physicochemical properties; however, achieving the controllable fabrication of freestanding 2D nanosheets through a template-free method under physiological conditions remains challenging. Here, an enzyme catalysis induced nanocluster assembly (ECINA) was proposed to fabricate freestanding micrometer-sized 2D nanosheets using peptide-capped gold nanoclusters (AuNCs) under mild aqueous conditions. An alkaline phosphatase (ALP)-cleavable peptide (YPFTEFCC) was designed and utilized as a ligand for the preparation of gold nanoclusters (YPF-AuNCs). Upon ALP catalysis, dephosphorylation induced peptide assembly and further lined up the nanoclusters, resulting in monolayered nanosheets with enhanced near-infrared-II (NIR-II) emission. Systematic investigations revealed that the assemble peptide sequence and presence of nanocluster as cores were indispensable for 2D nanosheet construction, while the types of nanoclusters were well tolerated, where copper nanoclusters (YPF-CuNCs) afforded similar patterns under the same assembly paradigm. Importantly, overexpressed endogenous ALP could also trigger the in situ assembly of YPF-AuNCs, allowing enhanced cellular uptake and prolonged high-contrast NIR-II imaging. This work establishes a pioneering perspective for enzyme-triggered nanocluster assembly, guiding the formation of hierarchical nanostructures in a template-free manner.

The efficient detoxification of arsenite (As(III)) in anoxic waters remains a critical challenge. This study investigates the role of hydrogen nanobubbles (HNBs), spontaneously generated during the reaction of nanoscale zero-valent iron (nZVI) with water, in modulating the reactive interfaces of nZVI and enhancing the sequestration of toxic arsenic (As). The presence of HNBs significantly promotes the removal kinetics and capacity of As(III) by nZVI under anoxic aqueous conditions. Mechanistic studies, employing X-ray photoelectron spectroscopy and synchrotron radiation X-ray absorption near-edge structure analysis, reveal that HNBs facilitate the transformation of adsorbed As(III) into less toxic As(0) and As(V) within the iron oxide shell of nZVI. The inherent reducibility of HNBs was confirmed through reactions with 3,3',5,5'-tetramethylbenzidine (TMB, a substrate prone to oxidation) and levofloxacin (LEV, a photosensitizer), as well as by the direct detection of hydrogen radicals (•H) in the system. Furthermore, defects and fractures in the nZVI oxide shell are found to facilitate the interfacial transfer of atomic hydrogen radicals and hydroxyl radicals, thereby mediating the redox reactions of As(III) at the gas-liquid-solid triple interface. This work not only elucidates the mechanism behind the HNB-enhanced reactivity of nZVI but also presents a novel and efficient strategy for the sustainable remediation of water contaminated with heavy metal(loid)s.

Selective labeling of alcohol side chains in peptides and proteins remains a major challenge for biomolecule modification. Herein, we report a rapid, efficient, and highly selective method for labeling both serine and threonine residues using fluorosulfuryl isocyanate (FSI) reagent in hexafluoroisopropanol (HFIP) solvent under mild conditions. The labeling reaction proceeds to completion within 1 min at room temperature, with excellent tolerance for all proteinogenic amino acid side chains except cysteine. The resulting fluorosulfuryl carbamate products can be further diversified through sulfur(VI) fluoride exchange (SuFEx) with amines to generate sulfamide-linked conjugates, or through intramolecular macrocyclization with lysine side chains to yield stapled peptides via Ser/Thr-Lys pairs. Notably, the fluorosulfuryl carbamate tag can be selectively eliminated under mildly basic aqueous conditions to generate dehydroamino acid residues, which serve as versatile electrophilic handles for one-pot conjugation with thiols, amines, or phosphines. Together, this platform offers a convenient strategy for site-selective editing of peptide alcohol side chains into structurally and functionally diverse deoxygenative analogs.

Comprehensive Summary To address the critical challenges of inefficient charge separation and uncontrollable selectivity in plastic photocatalytic upcycling, a MoS 2 /BiOCl heterojunction was designed. The precisely engineered interface created a built‐in electric field that enhanced charge separation and optimized the oxidation pathway. Specifically, the moderate oxidation potential of MoS 2 prevents polylactic acid (PLA) mineralization, while the negative conduction band of BiOCl facilitates hydroxyl radicals (·OH) generation via oxygen reduction. The hole and ·OH establish a synergistic dehydrogenation pathway, significantly boosting both reaction rate and product selectivity. The band structure modulation induced by the interface engineering reduces the free energy change for the lactic acid in the key dehydrogenation step from +0.29 eV to –0.13 eV, turning an endergonic into a spontaneous process. Under aqueous conditions at 20 °C, the optimized catalyst exhibits 93% selectivity for pyruvic acid formation at a remarkable rate of 3.46 mmol·h ‐1 ·g cat. ‐1 , outperforming BiOCl and MoS 2 by up to 31.5‐fold and 2.4‐fold, respectively, ranking it among the forefront of reported non‐noble‐metal photocatalysts. This system achieves a 77.6% carbon conversion, while the apparent quantum efficiency is 0.23% under 420 nm irradiation. This work presents a strategy for high‐selectivity in plastic upcycling under mild conditions, enabling green and precise waste conversion.

Resilin, an elastic protein found in insect cuticles, is exceptionally resilient because of its amino acid sequence and dityrosine cross-linking. In this study, the chemoenzymatic synthesis of resilin-mimetic polypeptides based on minimal peptide motifs incorporating glycine, proline, serine, and tyrosine residues is reported. Using papain-catalyzed copolymerization of tripeptide motifs (GPG: glycine-proline-glycine and SYS: serine-tyrosine-serine) and subsequent dityrosine cross-linking with horseradish peroxidase, we synthesized polypeptides mimicking key structural features of resilin. SYS-rich and GPG-rich copolypeptides were selectively separated from the polymerization mixture based on solubility. Structural analyses revealed that the SYS-rich copolypeptides adopted β-sheet-rich conformations and exhibited low solubility, whereas the GPG-rich copolypeptides were disordered and highly soluble. Despite their lower molecular weight, the GPG-rich copolypeptides formed stable dityrosine cross-linked networks under aqueous conditions, as confirmed by spectroscopic and rheological measurements. These findings demonstrate that short, bioinspired peptide motifs can construct simplified yet structurally relevant resilin-mimetic materials.

Introduction: Chalcones are important α, β-unsaturated carbonyl compound scaffolds in medicinal chemistry because of their structural simplicity and diverse biological activities, especially their anticancer potential. Developing environmentally friendly and efficient synthetic methods for chalcone derivatives remains a key research goal. Methods: An eco-friendly, one-pot synthetic substituted chalcone derivatives using Amberlyst® 15 as a reusable heterogeneous acid catalyst in water. The aldol condensation between substituted benzaldehydes and acetophenones was carried out under mild conditions (60-70°C). All synthesized compounds were characterized by LC-MS, 1H, and 13C NMR spectroscopy. Molecular docking studies were performed against the PARP protein (PDB ID: 3GEY), and the most promising compound was further evaluated for in vitro cytotoxicity using the MTT assay on MCF-7 breast cancer cells. results: For the objectives of our investigation and the optimization of reaction conditions, we first focused on the selective formation of (E)-3-(2-ethoxy-5-(methylthio)phenyl)-1-(4-fluorophenyl)prop-2-en-1-one (1aa), achieved by combining the benzaldehyde derivative 1a and benzophenone 1b. The optimization process involved varying the type and Amberlyst® 15 Ion Exchange Resin as an Acid Catalyst, Water as a green solvent, and their equivalents, while maintaining a reaction temperature of 60-70°C for 24 hours. Results: The developed methodology afforded chalcone derivatives in excellent yields of up to 95%, with simple work-up, catalyst recyclability, and elimination of hazardous solvents. Docking studies revealed that compound 1aa exhibited the strongest binding affinity toward PARP (-9.099 kcal/mol), surpassing the reference drug Niraparib (-7.825 kcal/mol). In vitro evaluation showed that compound 1aa displayed moderate cytotoxic activity against MCF-7 cells with an IC50 value of approximately 18 µM and significantly reduced intracellular reactive oxygen species levels. Discussion: The findings demonstrate the efficiency of Amberlyst® 15 as a green catalyst and highlight the role of substituent effects in enhancing biological activity. Conclusion: In summary, a green and efficient one-pot synthetic method for chalcone derivatives was successfully developed using Amberlyst® 15 as a reusable solid acid catalyst under aqueous conditions.

Tris(pyrazolyl)methanesulfonate (Tpms) ligands constitute water-compatible scorpionate platforms that combine the facial N,N,N donor set of classical tris(pyrazolyl)borates (Tp) or tris(pyrazolyl)methane (Tpm) with an appended sulfonate functionality that enhances hydrolytic robustness, solubility in polar media and coordination flexibility. Over the last two decades, Tpms chemistry has evolved from simple alkali-metal salts into structurally diverse complexes spanning much of the periodic table, in which the sulfonate group may remain non-coordinating or engage as an auxiliary, often hemilabile, donor. This donor complementarity enables κ3/κ2 coordination switching, modulation of nuclearity, access to multinuclear and polymeric architectures, and fine control over metal-centre environments. In this Perspective, we critically analyse the emerging structure-property relationships that govern Tpms coordination modes, stability and dimensionality and assess how these features translate into enabling functions in oxidation and carbonylation catalysis, Lewis-acid-mediated C-C bond formation, biologically active silver and copper systems, and coordination polymer design. Finally, we outline key challenges and opportunities for the field, including rational ligand-design strategies to control sulfonate engagement, the need for mechanistic benchmarking under aqueous and green conditions, and the potential of Tpms ligands as general scaffolds for sustainable and functional inorganic chemistry.