Catalytic Site Research Articles

A stable dual-function lanthanum MOF: Simultaneous CO2 capture and catalysis

Carbon dioxide (CO2) capture has become a hot topic in recent years because of global warming issues. However, most research has focused primarily on gas capture, with limited methods available for achieving both CO2 capture and conversion within a single material. Here, we synthesized FMU-101, a metal-organic framework (MOF) with metal-open sites, through the self-assembly of [1,1′-Biphenyl]-3,3′,5-tricarboxylic acid and lanthanide ions in a solvothermal environment. FMU-101 features hexagonal one-dimensional pores with a diameter of 1.4 nm. The presence of free dimethylamine cations and metal open sites in the channel contributes to its remarkable capability for selectively enriching CO2 from CO2/CH4 mixtures in dynamic breakthrough experiments. Furthermore, the metal-open sites in FMU-101 play a crucial role in CO2 fixation, serving as effective catalytic sites for converting the adsorbed CO2 into high-value chloropropylene carbonate, a versatile chemical intermediate. The segregation and conversion mechanisms were further elucidated through density-functional theory (DFT) calculations and Grand Canonical Monte Carlo (GCMC) simulations, which highlighted the critical role of metal-open sites in CO2 adsorption and transformation.

Electrocatalytic degradation of naphthenic acids using reduced graphene oxide modified nickel foam cathode: Role of surface structure and superoxide radical

In this work, the reduced graphene oxide (RGO) modified nickel foam (Ni-foam) was prepared via the hydrothermal reduction self-assembly method and was applied as the cathode for the effective electrocatalytic (EC) degradation of recalcitrant naphthenic acids (NAs) that are abundantly present in the petroleum industrial wastewater. The Ni@RGO cathode has greatly enhanced the production of H2O2 in the system to boost the degradation of 1-adamantanecarboxylic acid (ACA) that was a model NA compound. Results showed that the EC/Fe(III)/Ni@RGO system achieved complete ACA degradation within 15 min due to its elevated H2O2 generation and Fe(III)/Fe(II) circulation, compared to EC/Fe(III)/Ni-foam and EC/Fe(III)/Graphite systems. Interestingly, abundant ·O2– radicals, which were produced in EC/Fe(III)/Ni@RGO system as a key intermediate for 2e- oxygen reduction reaction (ORR), could effectively accelerate the circulation of Fe(III)/Fe(II) to activate H2O2 to generate ·OH for ACA degradation. Results of material characterization, electrochemical analysis and density functional theory (DFT) calculations showed that Ni@RGO cathode has obtained elevated electron transfer efficiency compared to that of Ni-foam cathode. Surface structure of RGO, such as carbon edge and vacancy with specific configuration, residual –COOH oxygenation groups on RGO surface are main catalytic sites to enhance the capacity of 2e- ORR and electron capture processes in the system. This study provides new insights regarding the synthesis process of catalytic electrodes, the influence of carbon-based material structure on catalytic activity, and the critical role of free radicals in the electro-Fenton system with Ni@RGO cathode

Enhanced Visible‐Light‐Driven Photocatalytic Overall Splitting of Pure Water in a Porous Microreactor

AbstractPhotocatalytic overall splitting of pure water (H2O) without sacrificial reagent to hydrogen (H2) and oxygen (O2) holds a great potential for achieving carbon neutrality. Herein, by anchoring cobalt sulfide (Co9S8) as cocatalyst and cadmium sulfide (CdS) as light absorber to channel wall of a porous polymer microreactor (PP12), continuous violent H2 and O2 bubbling productions from photocatalytic overall splitting of pure H2O without sacrificial reagent is achieved, with H2 and O2 production rates as high as 4.41 and 2.20 mmol h−1 gcat.−1 respectively. These are significantly enhanced than those in the widely used stirred tank‐type reactor in which no O2 is produced and H2 production rate is only 0.004 mmol h−1 gcat.−1. Besides improved charge separation and interaction of H2O with photocatalyst in PP12, bonding interaction of Co9S8 with PP12 creates abundant catalytic active sites for simultaneous productions of H2 and O2, thus leading to the significantly enhanced H2 and O2 bubbling productions in PP12. This offers a new strategy to enhance photocatalytic overall splitting of pure H2O without sacrificial reagent.

Tuning the peroxidase-mimic activity of CuX-trithiocyanuric acid complexes for colorimetric detection of gastric cancer-associated D-amino acids

A cascade colorimetric detection of salivary D-amino acids (DAAs) holds promise for the preliminary screening diagnosis of gastric cancer. Pursuing metal-organic complexes with high peroxidase-mimic (POD-mimic) activity is crucial to enhance diagnosis efficiency. In this work, we developed a straightforward strategy in a “one-pot” process to modulate the POD-mimic activity of CuX-trithiocyanuric acid (CuX-TTCA) complexes. By adjusting the molar ratios of CuX (Cl, Br, and I) and TTCA during synthesis to modify the coordination configuration of Cu(I) in CuX-TTCA, we easily tuned their POD-mimic activities. Among them, CuCl-TTCA-2 with a feeding molar ratio of 2:1 for CuCl:TTCA exhibited remarkable POD-mimic activity attributed to its exposed catalytic active sites and efficient mass transfer ability during catalysis. Long-lived 1O2 was identified as the primary reactive oxygen intermediate. A highly sensitive and selective cascade colorimetric detection platform was developed for two typical DAAs associated with gastric cancer, namely D-proline and D-alanine, achieving limit of detection values of 1.1 and 0.8 μM, respectively. As a proof-of-concept application, our cascade detection platform demonstrated excellent specificity in distinguishing saliva samples between gastric cancer patients and healthy individuals. The outstanding selectivity and reliable outcomes from DAAs assay make our detection platform highly promising for preliminary screening diagnosis of gastric cancer and patient self-detection applications. Our straightforward strategy for tuning POD-mimic activity provides an in-depth understanding on structure-activity relationship in nanozymes, offering valuable opportunities to advance enzyme-mimic optimization for other potential applications.

Van der Waals interactions between nonpolar alkyl chains and polar oxide surfaces prevent catalyst deactivation in aldehyde gas sensing

Catalysis-based electrical sensing of volatile organic compounds on metal oxide surfaces is a powerful method for molecular discrimination. However, catalyst deactivation caused by the poisoning of catalytic sites by analytes and/or catalyzed products remains a challenge. This study highlights the underestimated role of van der Waals interactions between hydrophobic aliphatic alkyl chains and hydrophilic ZnO surfaces in mitigating catalyst deactivation during aliphatic aldehyde sensing. By immobilizing octadecylphosphonic acid (ODPA) on ZnO nanowire sensors, recovery times for nonanal detection are significantly reduced without compromising sensitivity. Temperature-programmed measurements demonstrate a reduction in desorption temperature of carboxylates on ODPA-modified ZnO to below 150 °C, whereas carboxylates on bare ZnO remain above 300 °C, indicating a significant decrease in catalyst deactivation. Density functional theory calculations reveal that accumulated van der Waals interactions between alkyl chains and ZnO surfaces significantly contributed to adsorption molecular kinetics. IR spectroscopy using deuterated self-assembled monolayers (SAMs) reveals conformational changes of alkyl chains within the SAMs caused by aldehyde adsorption, supporting the suggested adsorption kinetics. A model is proposed based on the dynamic surface-covering by alkyl chains destabilizes catalytically oxidized carboxylic acids.

Promoting Water Dissociation and Weakening Active Hydrogen Adsorption to Boost the Hydrogen Transfer Reaction over a Cu−Ag Superlattice Electrocatalyst

AbstractThe prerequisite for electrocatalytic hydrogenation reactions (EHRs) is H2O splitting to form surface hydrogen species (*H), which occupy catalytic sites and lead to mismatched coverage of *H and reactants, resulting in unsatisfactory activity and selectivity. Thus, modulating the splitting pathway of H2O is significant for optimizing the EHR process. Herein, a Cu−Ag alloy with a superlattice structure of staggered‐ordered Cu and Ag is theoretically predicted and experimentally proven to undergo a pathway for H2O splitting called the hydrogen transfer reaction (HTR) in the water layer, which involves the formation of *H, the capture of *H by a water cluster to form H*(H2O)x and subsequent hydrogenation reactions by H*(H2O)x. Taking acetylene hydrogenation as a model case, the as‐proposed HTR pathway could lead to a relaxation hydrogenation process to modulate the matching degree of C2H2 and *H, thus enabling a 91.2 % C2H4 Faradaic efficiency at a partial current density of 0.38 A cm−2, greatly outperforming its counterpart without a superlattice structure.

Synergistic Surface Engineering of BiVO4 Photoanodes for Improved Photoelectrochemical Water Oxidation.

Surface engineering of BiVO4 photoanodes is effective and feasible for photoelectrochemical (PEC) water splitting. To achieve superior PEC performance, however, more than one surface engineering method is usually indispensable, for which a positive synergistic effect is vital and thus highly desired. Herein, it is reported that the incorporation of borate moieties into ultrathin p-type NiOx catalysts can induce the reconfiguration of surface catalytic sites to form new highly active species, in addition to enhanced fast charge separation and transfer. The photocurrent density of BiVO4 photoanodes is enhanced from 1.49 to 5.76 mA cm-2 at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5G illumination, which is achieved by successive modifications of NiOx and borate moieties. It is found that BO3 groups anchored to Ni atoms by replacing the surface hydroxyl sites of NiOx catalysts not only increase the relative ratio of Ni3+ species to facilitate charge transfer but also provide efficient active sites for H2O molecule adsorption and oxidation reactions. This work demonstrates the positive synergistic effect of these two surface engineering methods and provides an effective pathway to construct highly efficient and stable photoanodes for PEC water splitting.

Comparative Study of Docking Tools for Evaluation of Potential Copper Metallodrugs and Their Interaction with TMPRSS2

COVID-19 has caused over seven million deaths globally due to its high transmission rate. The virus responsible for the disease requires a transmembrane protease serine type II (TMPRSS2-7MEQ) to infiltrate host cells and has been linked to several cancers, particularly prostate cancer. To investigate COVID-19 potential therapies, a series of Casiopeina-like copper complexes containing 1,10-Phenanthroline and amino acids were investigated as TMPRSS2 inhibitors. The molecular structures of twelve Phenanthroline copper complexes were calculated, and their global reactivity indices were analyzed using DFT and conceptual DFT methods. Three molecular docking algorithms were employed to identify the most effective inhibitors by examining their interactions with amino acid residues in the target protein’s catalytic activity triad (Asp345, His296, and Ser441). All complexes are docked above the catalytic site, blocking the interaction with substrates. The Phenanthroline complexes showed better interactions than the Bipyridine complexes, likely due to increased hydrophobic contacts. Analogs’ cationic nature and amino acids’ basic side chains bring them near the active site by interacting with Asp435. The top complexes in this study contain Ornithine, Lysine, and Arginine, making them promising alternatives for researching new drugs for COVID-19 and cancers like prostate cancer.

Full‐Spectrum Light‐Harvesting Solar Thermal Electrocatalyst Boosts Oxygen Evolution

AbstractEnabling high‐efficiency solar thermal conversion (STC) at catalytic active site is critical but challenging for harnessing solar energy to boost catalytic reactions. Herein, we report the direct integration of full‐spectrum STC and high electrocatalytic oxygen evolution activity by fabricating a hierarchical nanocage architecture composed of graphene‐encapsulated CoNi nanoparticle. This catalyst exhibits a near‐complete 98 % absorptivity of solar spectrum and a high STC efficiency of 97 %, which is superior than previous solar thermal catalytic materials. It delivers a remarkable potential decrease of over 240 mV at various current densities for electrocatalytic oxygen evolution under solar illumination, which is practically unachievable via traditionally heating the system. The high‐efficiency STC is enabled by a synergy between the regulated electronic structure of graphene via CoNi‐carbon interaction and the multiple absorption of lights by the light‐trapping nanocage. Theoretical calculations suggest that high temperature‐induced vibrational free energy gain promotes the potential‐limiting *O to *OOH step, which decreases the overpotential for oxygen evolution.

Computational and theoretical insights into the cytotoxic prospects of compounds isolated from Elaeodendron buchananii against Leukemia

The present study investigated the cytotoxic prospects of isolated compounds from Elaeodendron buchananii against leukemia, using computational tools. Comprehensive literature searches revealed only buchaninoside, mutangin, methyl 3β-acetoxy-11α, 19α, 28-trihydroxyurs-12-en-23-oic acid, 3β, 11α, 19α-trihydroxyurs-12-en-23, 28-dioic acid, 3β-acetoxy-19α, 24, 28-trihydroxyurs-12-ene, 3-oxo-19α,28-dihydroxyurs-12-en-24-oic acid, and elabunin have been isolated from E. buchananii. The compounds were subjected to Density Functional Theory (DFT) and Molecular Dynamics (MD) analyses, with Fms-like tyrosine kinase (FLT3) and catalytic binding sites of Murine Leukemia Virus (MLV) as the target proteins in lukemia. Following DFT analysis, the structures of the compounds were optimized at the PW6B95D3/Def2-TZVP level of theory; their UV-Visible peaks were in the UV region, with mutangin, 3-oxo-19α,28-dihydroxyurs-12-en-24-oic acid and elabunin exhibiting one single peak. The potent Root-Mean-Square Deviation, Root-Mean-Square Fluctuation, solvent-accessible surface area and radius of gyration values indicated a strong and stable molecular interaction between the compounds and the proteins. These were further supported by high ∆G values, with MLV showing the best interaction. Per-residue decomposition plots also revealed high energy contributions in the interactions’ binding sites residues. These results indicate that the cytotoxic prospects of the isolated compounds against leukemia as indicated by its molecular interactions with FLT3 and MLV.

Effective drug design screening in bacterial glycolytic enzymes via targeting alternative allosteric sites

Three glycolytic enzymes phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (GADPH) and pyruvate kinase (PK) that belong to Staphylococcus aureus were used as targets for screening a dataset composed of 7229 compounds of which 1416 were FDA-approved. Instead of catalytic sites, evolutionarily less conserved allosteric sites were targeted to identify compounds that would selectively bind the bacteria's glycolytic enzymes instead of the human host. Seven different allosteric sites provided by three enzymes were used in independent screening experiments via docking. For each of the seven sites, a total of 723 compounds were selected as the top 10 % which displayed the highest binding affinities. All compounds were then united to yield the top 54 drug candidates shared by all seven sites. Next, 17 out of 54 were selected and subjected to in vitro experiments for testing their inhibition capability for antibacterial growth and enzymatic activity. Accordingly, four compounds displaying antibacterial growth inhibition above 40 % were determined as Candesartan cilexetil, Montelukast (sodium), Dronedarone (hydrochloride) and Thonzonium (bromide). In a second round of experiment, Candesartan cilexetil and Thonzonium displayed exceptionally high killing efficiencies on two bacterial strains of S.aureus (methicillin-sensitive and methicillin-resistant) with concentrations as low as 4 μg/mL and 0.5 μg/mL. Yet, their enzymatic assays were not in accordance with their killing effectiveness. Different inhibitory effects was observed for each compound in each enzymatic assay. A more effective target strategy would be to screen for drug compounds that woud inhibit a combination of glycolytic enzymes observed in the glycolytic pathway.

Highly Stable Propane Dehydrogenation on a Self‐Supporting Single‐Component Zn2SiO4 Catalyst

AbstractCurrent industrial propane dehydrogenation (PDH) processes predominantly use either toxic Cr‐based or expensive Pt‐based catalysts, necessitating urgent exploration for alternatives. Herein, we present Zn2SiO4, an easily prepared, cost‐effective material, as a highly efficient and stable catalyst for PDH. Uniquely, Zn2SiO4 nanocrystals do not require dispersion on support materials, commonly needed for catalytic active oxide clusters, but function as a self‐supporting catalyst instead. During the reaction‘s induction period, surface Zn species on the Zn2SiO4 crystal reduce to coordinately unsaturated ZnOx single sites, serving as highly active catalytic centers. The Zn2SiO4 catalyst demonstrates a stable performance over 200 hours of PDH operation at 550 °C. We further find that introducing a minuscule amount of CO2 into the propane feed significantly extends the catalyst lifespan to over 2000 hours. This enhancement arises from the special role of CO2 in facilitating the removal of strongly adsorbed H*, preventing the complete reduction of ZnOx. After prolonged reaction, the activity of Zn2SiO4 can be fully restored by etching the surface layer to expose fresh Zn species, available throughout the crystals. The combination of CO2introduction and catalytic site regeneration strategies is expected to enable a year‐long PDH operation using a single batch of Zn2SiO4 catalyst.

Highly Stable Propane Dehydrogenation on a Self-Supporting Single-Component Zn2SiO4 Catalyst.

Current industrial propane dehydrogenation (PDH) processes predominantly use either toxic Cr-based or expensive Pt-based catalysts, necessitating urgent exploration for alternatives. Herein, we present Zn2SiO4, an easily prepared, cost-effective material, as a highly efficient and stable catalyst for PDH. Uniquely, Zn2SiO4 nanocrystals do not require dispersion on support materials, commonly needed for catalytic active oxide clusters, but function as a self-supporting catalyst instead. During the reaction's induction period, surface Zn species on the Zn2SiO4 crystal reduce to coordinately unsaturated ZnOx single sites, serving as highly active catalytic centers. The Zn2SiO4 catalyst demonstrates a stable performance over 200 hours of PDH operation at 550 °C. We further find that introducing a minuscule amount of CO2 into the propane feed significantly extends the catalyst lifespan to over 2000 hours. This enhancement arises from the special role of CO2 in facilitating the removal of strongly adsorbed H*, preventing the complete reduction of ZnOx. After prolonged reaction, the activity of Zn2SiO4 can be fully restored by etching the surface layer to expose fresh Zn species, available throughout the crystals. The combination of CO2introduction and catalytic site regeneration strategies is expected to enable a year-long PDH operation using a single batch of Zn2SiO4 catalyst.

The structural Basis of NMN synthesis catalyzed by NadV from Haemophilus ducreyi

NMN is a precursor in the biosynthesis of NAD+, a molecule that plays a crucial role within cells. Supplementation with NMN can elevate NAD+ levels in the blood, improving symptoms of diabetes, neurodegenerative diseases, and cancer, as well as providing anti-aging benefits. Escherichia coli was engineered to heterologously express nicotinamide phosphoribosyltransferase (Nampt), enabling the recombinant E. coli to synthesize NAD derivatives from nicotinamide. The 3D structure of Nadv complexed with NAM and NMN was determined to explore the molecular mechanism by which Nadv catalyzes NMN synthesis. NAM binds at two sites: one at the catalytic site and one at the allosteric binding site, while NMN binds exclusively at the catalytic site. In both structural models, a loop between β15 and β16 is missing, likely due to its high flexibility, leading to diffuse electron density. Compared with other resolved Nampt structures, an additional 12-amino-acid loop was identified after α-helix 12 near the catalytic site. This study lays the groundwork for the engineering of Nadv, facilitating its efficient application in biological synthesis of NMN.

UiO-66(Zr)-2OH-Supported Pd0 NP Catalysts Accelerated a Fenton-Like Reaction: Iron Cycling and Hydrogen Peroxide Generation Achieved Simultaneously.

Both the sluggish kinetics of Fe(II) regeneration and usage restriction of H2O2 have severely hindered the scientific progress of the Fenton reaction toward practical applications. Herein, a reduction strategy of activated hydrogen, which was used to simultaneously generate H2O2 and accelerate the regeneration of ferrous in a Fenton-like reaction based on the reduction of activated hydrogen derived from H2, was proposed. Two types of composite catalysts, namely, Pd/UiO-66(Zr)-2OH and Pd@UiO-66(Zr)-2OH, were successfully prepared by loading nano-Pd particles onto the outer and inner pores of UiO-66(Zr)-2OH in different loading modes, respectively. They were used to enhance the reduction of activated hydrogen. The characterization results based on the analysis of scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy revealed that the materials were successfully prepared. By using a trace amount of ferrous iron and without adding H2O2, trimethoprim (C0 = 20 mg·L-1), as a target pollutant, could be nearly 100% degraded within 180 min in the reaction system composed of these two materials. The cycle of iron and the self-generation of H2O2 were verified by the detection of ferrous H2O2 in the system. Density functional theory calculation results further confirmed that the pore-filled Pd0 NPs, as the main catalytic site for Pd@UiO-66(Zr)-2OH, could produce H2O2 under the combined action of hydrogen and oxygen. The Pd@UiO-66(Zr)-2OH system had excellent stability after multiple applications (at least 6 cycles), all of which resulted in 100% removal of trimethoprim. The degradation efficiency of the Pd/UiO-66(Zr)-2OH system for TMP gradually decreased from 97 to 80% after six cycles. The results of electron paramagnetic resonance combined with classical radical burst experiments revealed the degradation pathways in the reaction system with hydroxyl radicals and singlet oxygen as the main reactive oxygen particles.

Durable fluorinated cobalt oxyhydroxide/calcium alginate hydrogels for activating peroxymonosulfate to enable nearly 100% degradation of ciprofloxacin.

Peroxymonosulfate (PMS) activation by solid catalysts for ciprofloxacin (CIP) removal is a promising method for decontaminating wastewater. However, mainstream catalysts suffer from efficiency and durability issues due to mechanical fragility and structural instability. Here, we have developed a durable calcium alginate hydrogel encapsulating fluorinated cobalt oxyhydroxide (FCO/CAH), fabricated by a simple hydrogen-bond-assisted cross-linking reaction, to enhance PMS activation for complete CIP removal. The optimized 2-FCO/CAH could generate abundant singlet oxygen (1O2) and sulfate radicals (SO4˙-) with PMS, resulting in 0.433 min-1 kinetic constant and approximately 100% CIP degradation within 10 minutes. This exceptional degradation efficiency is due to the even distribution of 2-FCO, which maximizes catalytic sites for PMS activation, and the multichannel cavity structure of CAH, which effectively enriches both PMS and CIP. Furthermore, the durability of 2-FCO/CAH was proved by its negligible decay in CIP removal efficiency (∼100%) and good microstructure retention after 6 consecutive cycles, facilitated by a stable surface reconstructed interphase on the 2-FCO surface and the strong mechanical property of 2-FCO/CAH. Our work showcases a facile approach to constructing durable hydrogel catalysts that improve PMS-mediated antibiotic degradation.

D-Band-Center-Engineered Platinum-Based Nanozyme for Personalized Pharmacovigilance.

A high-efficiency PtZnCd nanozyme was screened with density functional theory (DFT) and unique d-orbital coupling features for sensitive enrichment and real-time analysis of CO-releasing molecule-3 (CORM-3). Multicatalytic sites in the nanozyme showed a high reactivity of up to 72.89 min-1 for peroxidase (POD)-like reaction, which was 2.2, 4.07, and 14.67 times higher than that of PtZn (32.67 min-1), PtCd (17.89 min-1), and Pt (4.97 min-1), respectively. Normalization of the catalytic sites showed that the catalytic capacity of the active site in PtZnCd was 2.962 U μmol-1, which was four times higher than that of a pure Pt site (0.733 U μmol-1). DFT calculations showed that improved d-orbital coupling between different metals reduces the position of the center of the shifted whole d-band relative to the Fermi energy level, thereby increasing the contribution of the sites to the electron transfer from the active center, accompanied by enhanced substrate adsorption and intermediate conversion in the catalytic process. The potential adsorption principle and color development mechanism of CORM-3 on PtZnCd were determined, and its practical application in drug metabolism was validated in vitro and in zebrafish and mice models, demonstrating that transition-metal doping effectively engineers high-performance nanozymes and optimizes artificial enzymes.

Autocatalysis‐Integrated Bioorthogonal (Poly)Catalyst‐Linked Immunosorbent Assay for Living Cell Membrane Antigens

Immunoassay methods, notably enzyme‐linked immunosorbent assays (ELISAs), renowned for their signal amplification capabilities, are extensively employed in scientific research and clinical diagnostics. However, the instability of enzymes and their sensitivity to cellular environments present significant challenges for the broad application of ELISA in living cells. In this work, we present a bioorthogonal (poly)catalysis‐linked immunosorbent assay (BCLISA) designed for the detection of cell membrane antigens, which involves coupling bioorthogonal catalysts based on small molecules or polymers to antibodies. After screening, we opted for the copper(I)‐catalyzed azide‐alkyne cycloaddition (CuAAC) as the core reaction system. The polymer‐based catalysts exhibit enhanced reactivity at the same molecular concentration due to their multiple catalytic sites. Polytriazoles formed during the CuAAC reaction have the ability to chelate Cu(I), therebypromoting faster catalysis. By harnessing this autocatalytic feature, we successfully increased the signal amplification potential of BCLISA. Ultimately, this autocatalysis‐integrated BCLISA technique was employed for antigen detection and imaging on both in vitro and living cell membranes. This approach offers a new method for the detection and imaging of low‐abundance antigens on living cells.

Autocatalysis-Integrated Bioorthogonal (Poly)Catalyst-Linked Immunosorbent Assay for Living Cell Membrane Antigens.

Immunoassay methods, notably enzyme-linked immunosorbent assays (ELISAs),renowned for their signal amplification capabilities, are extensively employed in scientific research and clinical diagnostics. However, the instability of enzymes and their sensitivity to cellular environments present significant challenges for the broad application of ELISA in living cells. In this work, we present a bioorthogonal (poly)catalysis-linked immunosorbent assay (BCLISA) designed for the detection of cell membrane antigens, whichinvolvescoupling bioorthogonal catalysts based on small molecules or polymers to antibodies. After screening, we opted for the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) as the core reaction system. The polymer-based catalysts exhibit enhanced reactivity at the same molecular concentration due to their multiple catalytic sites. Polytriazoles formed during the CuAAC reaction have the ability to chelate Cu(I),therebypromoting faster catalysis. By harnessing this autocatalytic feature, we successfully increased the signal amplification potential of BCLISA. Ultimately, this autocatalysis-integrated BCLISA technique was employed for antigen detection and imaging on bothin vitroand living cell membranes. This approachoffersa new method for the detection and imaging of low-abundance antigens on living cells.

D‐Band‐Center‐Engineered Platinum‐Based Nanozyme for Personalized Pharmacovigilance

AbstractA high‐efficiency PtZnCd nanozyme was screened with density functional theory (DFT) and unique d‐orbital coupling features for sensitive enrichment and real‐time analysis of CO‐releasing molecule‐3 (CORM‐3). Multicatalytic sites in the nanozyme showed a high reactivity of up to 72.89 min−1 for peroxidase (POD)‐like reaction, which was 2.2, 4.07, and 14.67 times higher than that of PtZn (32.67 min−1), PtCd (17.89 min−1), and Pt (4.97 min−1), respectively. Normalization of the catalytic sites showed that the catalytic capacity of the active site in PtZnCd was 2.962 U μmol−1, which was four times higher than that of a pure Pt site (0.733 U μmol−1). DFT calculations showed that improved d‐orbital coupling between different metals reduces the position of the center of the shifted whole d‐band relative to the Fermi energy level, thereby increasing the contribution of the sites to the electron transfer from the active center, accompanied by enhanced substrate adsorption and intermediate conversion in the catalytic process. The potential adsorption principle and color development mechanism of CORM‐3 on PtZnCd were determined, and its practical application in drug metabolism was validated in vitro and in zebrafish and mice models, demonstrating that transition‐metal doping effectively engineers high‐performance nanozymes and optimizes artificial enzymes.