Mixed-valence Ce-Fe bimetallic MOFs with multi-enzyme-like activities for colorimetric biosensing and catalytic degradation.

Dual-functional trimetallic nanozyme with computation-aided interpretation for synergistic degradation and detection of tetracycline antibiotics.

Multifunctional nanoprobe-enhanced capillary immunoassay: A sensitive dual mode SERS-photothermal biosensor for prostate cancer diagnosis.

Superior peroxidase-like activities of InVO4 hollow nanocuboid assemblies for colorimetric detection of hydrogen peroxide and glucose.

Theoretical insights into the peroxidase-like activity of N-doped, B-doped and B/N-Codoped graphene

Colorimetric and fluorometric dual-mode sensing of cefadroxil based on peroxidase-like activity of iron and nitrogen co-doped carbon dots.

Stable tensile-strained palladium hydride nanozymes with specifically enhanced peroxidase-like activity for intelligent glucose detection

Innovative sarcoma therapy using multifaceted nano-PROTAC-induced EZH2 degradation and immunity enhancement.

Artesunate loaded core-shell nanoplatform for the chemo-chemodynamic-photothermal synergistic cancer therapy.

Prolonged surface peroxidase-like activity of Fe3O4 nanoparticles/few-layered graphene composite: Elucidation using UV–Vis and ESR spectroscopy

Tetracycline residues in aquatic ecosystems, resulting from widespread antibiotic use, pose significant risks by fostering antibiotic resistance and threatening ecological and human health. Addressing the need for rapid, sensitive, and portable tetracycline detection, this study presents a novel device utilizing iron-coordinated carbon dots (CDs-Fe) derived from Chromolaena odorata as a peroxidase-mimic nanozyme. Synthesized via a one-step hydrothermal method, the CDs-Fe nanozyme exhibits enhanced catalytic activity, enabling a colorimetric assay with 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H₂O₂). Tetracycline detection relies on the nanozyme's peroxidase-like activity, where tetracycline competitively inhibits TMB oxidation, reducing the absorbance at 652nm due to surface adhesion and substrate competition. The assay achieves a detection limit of 1.34μM and a linear range of 17 to 67μM. A portable Arduino-based device, fabricated via 3D printing with smartphone-enabled Bluetooth data reading, was developed for on-site tetracycline monitoring in real water samples, showing recoveries of 95 to 102% and high selectivity against other antibiotics. Validated against UV-vis spectrophotometry, this green-synthesized, cost-effective system offers a sustainable and field-deployable solution for environmental water quality assessment.

Exploring sustainable and highly active catalysts for enzyme-like catalysis is vital for the development and application of nanozymes. Herein, we prepared Mn-doped MoS2 nanosheet (NSs)-supported hollow mesoporous carbon nanotubes (CNTs) through a one-pot hydrothermal reaction and a subsequent annealing treatment under nitrogen atmosphere. Using (NH4)2MoO4 and thiourea as the precursor of MoS2, MnO2 nanowires (NWs) provided the Mn source for doping MoS2 and as the initiator to promote the pyrrole polymerization to form a one-dimensional (1D) polypyrrole (PPy) shell. During sulfidation, released H+ cations diffused through PPy pores into the MnO2 NWs core, causing their dissolution. As a result, hierarchical 1D hierarchical PPy@Mn-MoS2 was successfully formed. After thermal treatment, the obtained nitrogen-doped CNTs@Mn-MoS2 exhibited excellent peroxidase-like activity and stability owing to the unique tubular structure and Mn-doped MoS2 NSs. This involves a self-sacrificial template and transition-metal doping; this strategy provides a method to precisely regulate the intrinsic catalytic activity and construct the tubular structure toward enzyme-like catalysis and other energy-related processes.

Although the Co3O4 nanozyme has been reported to exhibit peroxidase (POD) mimicking activity, its explicit catalytic mechanism remains indefinable. This study systematically investigates the POD-like catalytic mechanism of Co3O4 nanoparticles (NPs) through integrated experimental and theoretical approaches. The results reveal that their catalytic activity originates from dual synergistic pathways: the nonradical and the radical pathways. In the nonradical pathways, Co3O4 NPs mediate electron transfer from the substrate (e.g., 3,3',5,5'-tetramethylbenzidine, TMB) to H2O2 through the Co(III)/Co(II) redox couple, as its redox potential lies between that of TMB and H2O2. During the radical pathways, electron paramagnetic resonance (EPR) and fluorescent or UV-vis probe experiments demonstrate that H2O2 preferentially decomposes into superoxide radicals (O2•-) over hydroxyl radicals (•OH). Furthermore, density functional theory calculations reveal that H2O2 exhibits a relatively lower activation barrier (0.78 eV) to generate O2•- on the Co3O4 (110) facet, compared to the higher barrier (1.72 eV) for •OH formation. Additionally, the distinct degradation behaviors of organic dyes provide further validation of the proposed mechanism. This research will encourage further exploration into the catalytic mechanisms of nanozymes, thereby facilitating their rational design and application.

Osteoporosis, characterized by imbalanced bone metabolism and chronic inflammation, remains a therapeutic challenge due to the limitations of current single-target therapies. This study integrates transcriptomic insights with nanomaterial engineering to develop a multi-target strategy. Transcriptomic analysis of ovariectomized (OVX) mice reveals immune dysregulation and PI3K/Akt pathway activation, driving osteoclastogenesis. To address this, cobalt-aluminum layered double hydroxide nanosheets (f‑CA(OH)) are synthesized, which scavenge reactive oxygen species (ROS) via peroxidase-like activity and stabilize hypoxia-inducible factor 1α (HIF‑1α) to upregulate BMP2 expression. Co-culturing f‑CA(OH) with mesenchymal stem cells (MSCs) generate engineered exosomes (fCA‑BExo), encapsulating BMP2 and nanomaterials. In vitro, fCA‑BExo suppress osteoclast differentiation by blocking PI3K/Akt signaling and enhance osteogenesis via SMAD2/RUNX2 activation. In vivo, fCA‑BExo restored trabecular architecture in OVX mice, reduces pro-inflammatory cytokines, and promote M2 macrophage polarization, demonstrating biocompatibility and efficacy. This "immune-PI3K/Akt axis" targeting strategy offers a novel paradigm for osteoporosis treatment.

Artificial enzymes have been rapidly developed in recent years. However, the homogenous charge distribution of active sites hinders the enhancement of the substrate affinity and catalytic efficiency. Herein, a dual-heteroatom doping strategy is developed for the design and modulation of MOF-derived carbon hybrids (ZFPS: ZnS/FeP/Fe4P6N12S). By introducing electronegative P and S atoms, the coordination environment of the metal sites is tuned, leading to the formation of narrow bandgap materials with asymmetric charge distribution and electron-rich active sites. This structural optimization enhances both substrate adsorption-desorption capacity and electron transfer efficiency. Density functional theory calculations confirm that P, S co-doping modulates the D-band electronic structure of Fe sites, thereby enhancing the affinity between the substrates and the active sites. Compared to its counterpart without P, S doping, ZFPS exhibits a 33.3-fold increase in peroxidase-like activity (Kcat/Km), as well as superior halogen peroxidase-like and glutathione depletion capability. The multiple catalytic activities synergistically facilitate the rapid generation of highly toxic reactive oxygen species at low H2O2 concentrations, enabling effective eradication of bacterial biofilms, which is verified in anti-oral-biofilm application. This work establishes a facile strategy for improving the catalytic activities of artificial enzymes, which will promote the development of antimicrobial biomaterials.

Single-atom nanozymes (SANs), with their tunable metal active centers, enable the modulation of various enzyme activities for antitumor therapy. However, these materials encounter substantial challenges in cancer therapy owing to their limited biocompatibility and biodegradability. Additionally, the high-temperature pyrolysis process involved in their synthesis significantly restricts their practical, large-scale application. To address these challenges, we propose the construction of an LDH-based SAN exhibiting peroxidase-like (POD-like) activity and glutathione depletion capability. We successfully developed a SAN containing ruthenium (Ru) and copper (Cu) bimetallic atoms (MgAl-LDH/Ru/Cu), where Ru and Cu are distributed in single-atom dispersed states, forming nanodomains. The synergistic effects of the Ru/Cu bimetallic system enable MgAl-LDH/Ru/Cu to demonstrate superior POD-like and glutathione peroxidase-like (GPx-like) catalytic activities compared to those of MgAl-LDH/Ru or MgAl-LDH/Cu alone. Density functional theory calculations indicate that both Ru and Cu sites in MgAl-LDH/Ru/Cu exhibit lower energy barriers for POD-like and GPx-like reactions, likely due to enhanced electron loss states at the Ru/Cu bimetallic single-atom sites compared to those at Ru or Cu sites individually. Both in vitro and in vivo experiments demonstrate that the Ru/Cu bimetallic loading significantly outperforms the individual metal loadings of Ru or Cu in terms of anti-liver cancer efficacy. Importantly, by leveraging the precise correlation between the catalytic structural unit of MgAl-LDH-based SANs and enzyme activity, we further elucidated the potential contributions of POD-like and GPx-like activities to cancer therapy. MgAl-LDH-based multimetal SAN represents a synergistic multienzyme nanoplatform with a tunable elemental composition, paving the way for further investigations into the interplay between multienzyme activity and antitumor effects.

Multi-enzymic nanozymes have attracted growing attention due to their distinct advantages over single enzyme-like nanozymes, particularly their synergistic effects and cascaded reactions. Herein, iron-doped carbon dots (FeCDs) were prepared by a one-step calcination method using hemin chloride, histidine, and potassium citrate as precursors. The resultant FeCDs exhibit a monodispersed spherical structure with an average particle size of 1.1 nm, where iron acts as a key catalytic active center. Enzyme activity experiments demonstrate that FeCDs exhibit peroxidase-like, catalase-like, and photo-enhanced laccase-like activities. Through the cascade effect of catalase-like and laccase-like activities of FeCDs, the coupling rate of 2,4-dichlorophenol (2,4-DP) and 4-amino-antipyrine (4-AP) was significantly increased. Meanwhile, the peroxidase-like activity can catalyze H2O2 to form ˙OH, further increasing the oxidation rate of 2,4-DP. Kinetic experiments indicated that the Kcat/Km value of the combined action of the three enzyme-like activities was 3.35 times that of the peroxidase-like activity and 4.76 times that of the laccase-like activity, respectively. Based on the multi-enzyme activities of FeCDs, a series of phenolic compounds can be catalytically transformed into chromogenic products within 10 min at room temperature for the rapid determination of these compounds. The results obtained in this work not only provide a reliable strategy for the preparation of carbon-based nanomaterials with multi-enzyme activities, but also expand the application of carbon-based nanomaterials in the field of analysis.

Diabetic ulcers remain a persistent global health challenge. Developing therapeutic systems with antibacterial, antioxidant, anti-inflammatory, and pro-angiogenic properties presents a promising strategy for effectively and rapidly treating diabetic wounds and preventing the development of diabetic ulcers. Herein, a photo-cross-linked Flammulina velutipes polysaccharide (FVP) containing double bonds was obtained through extraction and purification of FVP, and a facile reaction using methacrylic anhydride. The FVP was further combined with caffeic acid-copper nanozyme (CCN) to fabricate a series of multifunctional photo-cross-linked hydrogels (FVP@CCN) for diabetic wound healing. The FVP@CCN demonstrated rapid degradability, tunable mechanical properties, considerable intrinsic antimicrobial activity, and excellent biocompatibility. Additionally, the incorporated CCN, possessing peroxidase-like nanozyme activity, further endowed FVP@CCN with strong photothermal-induced antimicrobial ability, reactive oxygen species (ROS) scavenging capability, angiogenesis promotion activities, and pH-responsive release of CA and Cu2+. In vivo studies confirmed that FVP@CCN provided synergistic treatment against multiple healing impairments associated with diabetic wounds, exhibiting hemostasis, sustainable antibacterial, antioxidant, anti-inflammatory, angiogenesis-promotion, cell-proliferation, and hair follicle-regeneration, ultimately resulting in a diabetic wound closure rate exceeding 90% within 7 days. The multifunctional FVP@CCN hydrogel holds significant potential for diabetic wound healing, and its fabrication strategy can be extended to other plant-based polysaccharide hydrogels.

An ultrasmall bimetallic Au2Pd3 nanozyme with self-cascade enzyme-like activities and robust photothermal heating properties is synthesized and encapsulated into a poly(vinyl alcohol)/hyaluronic acid (PVA/HA) matrix via a repeated freezing and thawing process to yield a hydrogel microneedle patch (Au2Pd3@PH). This microneedle displays a good tissue-piercing capability and thermal-responsive melting behavior. Upon exposure to an 808 nm near-infrared laser, Au2Pd3@PH dissolves and releases Au2Pd3, which shows glucose oxidase (GOx)-like catalytic activity for the conversion of endogenous glucose into gluconic acid and hydrogen peroxide (H2O2), thereby reducing the glucose level and local pH at the wound site. The reduced pH induces the peroxidase-like activity of Au2Pd3 to further oxidize H2O2 into the hydroxyl radical (•OH). In vitro experiments reveal that Au2Pd3@PH exhibits antibacterial rates exceeding 99% against both Staphylococcus aureus and Salmonella typhimurium, showing a photothermal/chemodynamic dual-mode synergistic antibacterial effect. Further in vivo assays demonstrate that the Au2Pd3@PH treatment group achieves near-complete healing of infected diabetic wounds within 7 days, indicating an enhanced wound healing process. The treatment with Au2Pd3@PH effectively modulates inflammatory factor expression, including marked downregulation of TNF-α and IL-6, while simultaneously promoting collagen deposition and angiogenesis, with no adverse biological effects observed. Therefore, the proposed Au2Pd3@PH hydrogel microneedle provides a promising strategy for treating diabetic wound infections with a high performance.

Biomolecular condensates formed via liquid-liquid phase separation (LLPS) are essential to cellular organization, catalysis, and regulation of biochemical pathways. Inspired by such natural systems, we present a new adaptive coacervate formed by multivalent salt-bridge interactions of polyhexamethylene biguanide (PHMB) polymer and adenosine triphosphate (ATP). These phase separated compartments efficiently sequester guanine-rich DNA sequences that adopt G-quadruplex (GQ) conformations in the presence of potassium ions. Hemin intercalates into these GQ structures to produce a catalytically active DNAzyme with amplified peroxidase-like activity. Within the coacervate, reduced molecular diffusion and increased local substrate concentrations synergistically augment the catalytic efficiency of the DNAzyme by 10-fold compared to that in the unconfined state. Integrating an enzymatic degradation cycle by alkaline phosphatase allows ATP-fueled dissipative behavior of the coacervates. By integrating self-assembling catalytic motifs within a dissipative host environment, this system demonstrates key principles of spatially and temporally regulated catalysis, mimicking features of cellular microreactors. Our work highlights the potential of synthetic LLPS-based platforms as tunable and compartmentalized catalytic systems, with implications for biomimetic reactor design and the development of advanced functional materials.