Application of green silver nano-particles as anti-bacterial and photo-catalytic degradation of azo dye in wastewater.

Ensuring everyone enjoys healthy lifestyles and well-being at all ages, Progress has been made in increasing access to clean water and sanitation facilities and reducing the spread of epidemics and diseases. The synthesis of nano-particles (NPs) by using microalgae is a new nanobiotechnology due to the use of the biomolecular (corona) of microalgae as a capping and reducing agent for NP creation. This investigation explores the capacity of a distinct indigenous microalgal strain to synthesize silver nano-particles (AgNPs), as well as its effectiveness against multi-drug resistant (MDR) bacteria and its ability to degrade Azo dye (Methyl Red) in wastewater.

Microenvironmental modulation breaks intrinsic pH limitations of nanozymes to boost their activities.

Functional nanomaterials with enzyme-mimicking activities, termed as nanozymes, have found wide applications in various fields. However, the deviation between the working and optimal pHs of nanozymes has been limiting their practical applications. Here we develop a strategy to modulate the microenvironmental pHs of metal-organic framework (MOF) nanozymes by confining polyacids or polybases (serving as Brønsted acids or bases).

Aza-[4 + 2]-cycloaddition of benzocyclobutenones into isoquinolinone derivatives enabled by photoinduced regio-specific C-C bond cleavage.

The activation of C-C bond of benzocyclobutenones under mild reaction conditions remains a challenge. We herein report a photoinduced catalyst-free regio-specific C1-C8 bond cleavage of benzocyclobutenones, enabling the generation of versatile ortho-quinoid ketene methides for aza-[4 + 2]-cycloaddition with imines, which offers a facile route to isoquinolinone derivatives, including seven family members of protoberberine alkaloids, gusanlung A, B, D, 8-oxotetrahydroplamatine, tetrahydrothalifendine, tetrahydropalmatine, and xylopinine. Furthermore, the catalytic enantioselective version of this strategy is also realized by merging synergistic photocatalysis and chiral Lewis acid catalysis.

Topological transformation of microbial proteins into iron single-atom sites for selective hydrogen peroxide electrosynthesis.

The emergence of single-atom catalysts offers exciting prospects for the green production of hydrogen peroxide; however, their optimal local structure and the underlying structure-activity relationships remain unclear. Here we show trace Fe, up to 278 mg/kg and derived from microbial protein, serve as precursors to synthesize a variety of Fe single-atom catalysts containing FeNO (1 ≤ x ≤ 4) moieties through controlled pyrolysis. These moieties resemble the structural features of nonheme Fe-dependent enzymes while being effectively confined on a microbe-derived, electrically conductive carbon support, enabling high-current density electrolysis.

Steering acidic oxygen reduction selectivity of single-atom catalysts through the second sphere effect.

Natural enzymes feature distinctive second spheres near their active sites, leading to exquisite catalytic reactivity. However, incumbent synthetic strategies offer limited versatility in functionalizing the second spheres of heterogeneous catalysts. Here, we prepare an enzyme-mimetic single Co-N atom catalyst with an elaborately configured pendant amine group in the second sphere via 1,3-dipolar cycloaddition, which switches the oxygen reduction reaction selectivity from the 4e to the 2e pathway under acidic conditions.

An adenosine analog shows high antiviral potency against coronavirus and arenavirus mainly through an unusual base pairing mode.

By targeting the essential viral RNA-dependent RNA polymerase (RdRP), nucleoside analogs (NAs) have exhibited great potential in antiviral therapy for RNA virus-related diseases. However, most ribose-modified NAs do not present broad-spectrum features, likely due to differences in ribose-RdRP interactions across virus families. Here, we show that HNC-1664, an adenosine analog with modifications both in ribose and base, has broad-spectrum antiviral activity against positive-strand coronaviruses and negative-strand arenaviruses.

Facile and Regioselective Deuteration of C2-Alkylated Imidazolium Salts in the Presence of Cesium Carbonate.

Thirteen imidazolium iodides bearing benzyl, mesityl, or 2,6-diiso-propyl-phenyl substituents on their nitrogen atoms, and C1 to C4 alkyl chains on their C2 carbon atom were readily deuterated with D2O as a cheap and non-toxic deuterium source in the presence of Cs2CO3, a weak, innocuous, inorganic base. The isotopic exchange proceeded quickly and efficiently under mild, aerobic conditions to afford a range of aNHC and NHO precursors regioselectively labeled on their C2α exocyclic position and/or C4=C5 heterocyclic backbone. A "carbene-free" mechanism was postulated, in which the carbonate anion acts as a catalyst to activate an exocyclic, acidic C-H bond and ease a deuterium transfer from D2O to the imidazolium salt in a concerted fashion.

Robust Immobilization and Activity Preservation of Enzymes in Porous Frameworks by Silica-Based "Inorganic Glue".

The development of novel methods to enhance enzyme-carrier interactions in situ, at a feasible cost, and on a large scale is crucial for improving the stability and durability of current immobilized enzyme systems used in industrial settings. Here, a pioneering approach termed "silica-based inorganic glue" is proposed, which utilizes protein-catalyzed silicification to fix enzyme within porous matrix while preserving enzyme activity. This innovative strategy offers several key benefits, including conformational stabilization of enzymes, improved interactions between enzymes and the matrix, prevention of enzyme leakage, and mitigation of pore blocking.

Could Metamaterials be the Next Frontier of Catalysis?

Plasmonic catalysis, whereby either an optically resonating metal couples to a catalytic material or a catalytic metal particle achieves optical resonance, has been a mainstay of photo-catalysis research for the past few decades. However, a new field of metal-dielectric metamaterials, including plasmonic metamaterials, is emerging as the next frontier in catalysis research. With new optical behaviors that can be achieved by sub-wavelength structures, in either periodic or semi-periodic arrangements, metamaterials can overcome some of the limitations of conventional plasmonic catalysis.

Homogenous catalysis of peroxynitrite conversion to nitrate by diaryl selenide: a theoretical investigation of the reaction mechanism.

Quenching peroxynitrite (a reactive oxidant species) is a vital process in biological systems and environmental chemistry as it maintains redox balance and mitigates damaging effects in living cells and the environment. In this study, we report a systematic analysis of the mechanism of transforming peroxynitrite into nitrate using diaryl selenide in water. Through quantum mechanical calculations, we investigate the dynamic isomerization of peroxynitrite in a homogeneous catalytic environment.

Co-immobilization of laccase and zinc oxide nanoparticles onto bacterial cellulose to achieve synergistic effect of photo and enzymatic catalysis for biodegradation of favipiravir.

The environmental persistence of pharmaceuticals represents a significant threat to aquatic ecosystems and human health, while limitations in conventional wastewater treatment methods underscore the urgent need for innovative and eco-friendly degradation strategies. Photobiocatalytic approaches provide a promising solution for the effective degradation of pharmaceutical contaminants by harnessing the synergistic effects of both photocatalysts and biocatalysts. In this study, we developed a photobiocatalytic composite by co-immobilizing laccase enzyme and zinc oxide nanoparticles on bacterial cellulose synthesized from orange peel waste.

Photoelectrochemical aptasensing and fluorescence imaging co-joint detecting MCF-7 cells in whole blood via an inertial separation microfluidic chip.

The mortality rate of tumor is still very high till now. Circulating tumor cells (CTCs) are the major culprit of high cancer mortality. To improve survival rate of cancer patients, real-time monitoring and quantitative detection of CTCs are of indescribable value.

Developing photoactivated artificial enzymes for sustainable fuel production.

Enzymes catalyze molecular reactions with remarkable efficiency and selectivity under mild conditions. Photoactivated enzymes make use of a light-absorbing chromophore to drive chemical transformations, ideally using sunlight as an energy source. The direct attachment of a chromophore to native enzymes is advantageous, as information on the underlying catalytic mechanisms can be obtained.

Fibrous MoS/BiS/BiFeO ternary heterojunction boosts piezoelectric photocatalytic performance.

Photocatalytic removal of antibiotic such as ciprofloxacin from polluted water is of great value for eco-environment protection. To further enhance the piezoelectric effect in photocatalysis, we designed and synthesized a ternary heterojunction piezoelectric photocatalyst through uniformly loading MoS nanosheets onto BiFeO (BFO) nanofibers, namely MoS/BiS/BFO. Piezoresponse force microscopy and Kelvin probe force microscopy demonstrated its enhanced piezoelectric properties, showing a maximum amplitude displacement of 395.

C(sp3)-H Bond Functionalization of 8-Methylquinolines.

Quinolines have emerged as essential components in various medicinal agents, playing a key role in treating various ailments. Numerous drugs with a quinoline core have been recognized for their antimalarial, antibacterial, and anticancer activities and have been successfully commercialized, including chloroquine, ciprofloxacin, topotecan, etc. Over the past two decades, we have witnessed a tremendous expansion in the C-H bond functionalization of quinoline scaffolds to widen this chemical space for drug discovery further.

Cytoprotective Effects and Intranuclear Localization of Sulfur-Containing Derivative of Buckminsterfullerene.

Background: There is a growing interest in exploring the biological characteristics of nanoparticles and exploring their potential applications. However, there is still a lack of research into the potential genotoxicity of fullerene derivatives and their impact on gene expression in human cells. In this study, we investigated the effects of a water-soluble fullerene derivative, C60[C6H4SCH2COOK]5H (F1), on human embryonic lung fibroblasts (HELF).

Metal-Independent Correlations for Site-Specific Binding Energies of Relevant Catalytic Intermediates.

Establishing energy correlations among different metals can accelerate the discovery of efficient and cost-effective catalysts for complex reactions. Using a recently introduced coordination-based model, we can predict site-specific metal binding energies (Δ ) that can be used as a descriptor for chemical reactions. In this study, we have examined a range of metals including Ag, Au, Co, Cu, Ir, Ni, Os, Pd, Pt, Rh, and Ru and found linear correlations between predicted Δ and adsorption energies of CH and O (Δ and Δ ) at various coordination environments for all the considered metals.

Concatenating Microbial, Enzymatic, and Organometallic Catalysis for Integrated Conversion of Renewable Carbon Sources.

The chemical industry can now seize the opportunity to improve the sustainability of its processes by replacing fossil carbon sources with renewable alternatives such as CO, biomass, and plastics, thereby thinking ahead and having a look into the future. For their conversion to intermediate and final products, different types of catalysts-microbial, enzymatic, and organometallic-can be applied. The first part of this review shows how these catalysts can work separately in parallel, each route with unique requirements and advantages.

Elucidating Thermodynamically Driven Structure-Property Relations for Zeolite Adsorption Using Neural Networks.

Understanding the origin and effect of the confinement of molecules and transition states within the micropores of a zeolite can enable targeted design of such materials for catalysis, gas storage, and membrane-based separations. Linear correlations of the thermodynamic parameters of molecular adsorption in zeolites have been proposed; however, their generalizability across diverse molecular classes and zeolite structures has not been established. Here, using molecular simulations of >3500 combinations of adsorbates and zeolites, we show that linear trends hold in many cases; however, they collapse for highly confined systems.

Selective Arene Photonitration via Iron-Complex β-Homolysis.

Nitroaromatics, as an important member and source of nitrogen-containing aromatics, is bringing enormous economic benefits in fields of pharmaceuticals, dyes, pesticides, functional materials, fertilizers, and explosives. Nonetheless, the notoriously polluting nitration industry, which suffers from excessive discharge of fumes and waste acids, poor functional group tolerance, and tremendous purification difficulty, renders mild, efficient, and environmentally friendly nitration a formidable challenge. Herein, we develop a visible-light-driven biocompatible arene C-H nitration strategy with good efficiency and regioselectivity, marvelous substrate applicability and functional group tolerance, and wide application in scale-up synthesis, total synthesis, and late-stage functionalization.

Singlets-Driven Photoredox Catalysts: Transforming Noncatalytic Red Fluorophores to Efficient Catalysts.

Red-light absorbing photoredox catalysts offer potential advantages for large-scale reactions, expanding the range of usable substrates and facilitating bio-orthogonal applications. While many red-light absorbing/emitting fluorophores have been developed recently, functional red-light absorbing photoredox catalysts are scarce. Many photoredox catalysts rely on long-lived triplet excited states (triplets), which can efficiently engage in single electron transfer (SET) reactions with substrates.

Visible Light-Driven Excited-State Copper-BINAP Catalysis for Accessing Diverse Chemical Reactions.

The use of visible light to drive chemical transformations has a history spanning over a century. However, the development of photo-redox catalysts to efficiently harness light energy is a more recent advancement, evolving over the past two decades. While ruthenium and iridium-based photocatalysts dominate due to their photostability, long excited-state lifetimes, and high redox potentials, concerns about sustainability and cost have shifted attention to first-row transition metals.

Multivariate analysis on the structure-activity parameters for nano CuO-catalyzed reduction reactions.

Understanding the origin of enhanced catalytic activity is critical to heterogeneous catalyst design. This is especially important for non-noble metal-based catalysts, notably metal oxides, which have recently emerged as viable alternatives for numerous thermal catalytic processes. For thermal catalytic reduction/hydrogenation using metal oxide nanoparticles, enhanced catalytic performance is typically attributed to increased surface area and oxygen vacancies.

A Regiospecific Co-Assembly Method to Functionalize Ordered Mesoporous Metal Oxides with Customizable Noble Metal Nanocrystals.

An efficient regiospecific co-assembly (RSCA) strategy is developed for general synthesis of mesoporous metal oxides with pore walls precisely decorated by highly dispersed noble metal nanocrystals with customized parameters (diameter and composition). It features the rational utilization of the specific interactions between hydrophilic molecular precursors, hydrophobic noble metal nanocrystals, and amphiphilic block copolymers, to achieve regiospecific co-assembly as confirmed by molecular dynamics simulations. Through this RSCA strategy, we achieved a controllable synthesis of a variety of functional mesoporous metal oxide composites (e.

Understanding Oxygen-Induced Reactions and Their Impact on n-Type Polymeric Mixed Conductor-Based Devices.

Electron transporting (n-type) polymeric mixed conductors are an exciting class of materials for devices with aqueous electrolyte interfaces, such as bioelectronic sensors, actuators, and soft charge storage systems. However, their charge transport performance falls short of their p-type counterparts, primarily due to electrochemical side reactions such as the oxygen reduction reaction (ORR). To mitigate ORR, a common strategy in n-type organic semiconductor design focuses on lowering the lowest unoccupied molecular orbital (LUMO) level.