Spontaneous immobilization of single atom in NbCT MXene as excellent nanozyme for detecting and preventing gastric mucosal injury.

Early diagnosis and treatment of gastric mucosal injury is crucial to prevent further gastritis and even canceration. As an efficient biocatalyst, single-atom nanozyme (SAzyme) is proposed to be an ideal candidate for the construction of multifunctional platforms. Nevertheless, SAzyme still faces challenges in detecting and treating diseases due to the complexity of preparation methods, limitations of enzyme activity, and undesirable biocompatibility.

Progress in antibacterial applications of nanozymes.

Bacterial infections are a growing problem, and antibiotic drugs can be widely used to fight bacterial infections. However, the overuse of antibiotics and the evolution of bacteria have led to the emergence of drug-resistant bacteria, severely reducing the effectiveness of treatment. Therefore, it is very important to develop new effective antibacterial strategies to fight multi-drug resistant bacteria.

Paper-based colorimetric sensor using bimetallic Nickel-Cobalt selenides nanozyme with artificial neural network-assisted for detection of HO on smartphone.

Paper-based analytical devices (PADs) integrated with smartphones have shown great potential in various fields, but they also face challenges such as single signal reading, complex data processing and significant environmental impacting. In this study, a colorimetric PAD platform has been proposed using bimetallic nickel-cobalt selenides as highly active peroxidase mimic, smartphone with 3D-printing dark-cavity as a portable detector and an artificial neural network (ANN) model as multi-signal processing tool. Notably, the optimized nickel-cobalt selenides (NiCoSe with Ni to Co ratio of 3/1) exhibit excellent peoxidase-mimetic activities and are capable of catalyzing the oxidation of four chromogenic reagents in the presence of HO.

Engineering Platelet Membrane-Coated Bimetallic MOFs as Biodegradable Nanozymes for Efficient Antibacterial Therapy.

Nanocatalytic-based wound therapeutics present a promising strategy for generating reactive oxygen species (ROS) to antipathogen to promote wound healing. However, the full clinical potential of these nanocatalysts is limited by their low reactivity, limited targeting ability, and poor biodegradability in the wound microenvironment. Herein, a bio-organic nanozyme is developed by encapsulating a FeZn-based bimetallic organic framework (MOF) (MIL-88B-Fe/Zn) in platelet membranes (PM@MIL-88B-Fe/Zn) for antimicrobial activity during wound healing.

Oxidase-like VC MXene nanozyme with inherent antibacterial properties for colorimetric sensing.

The microbial environment greatly affects the performance of colourimetric sensors, especially the interference of bacteria in the sample detected. This paper reports the fabrication of an antibacterial colorimetric sensor based on VC MXene synthesized via simple intercalation and stripping. The prepared VC nanosheets can mimic oxidase activity towards 3,3',5,5'-tetramethylbenzidine (TMB) oxidation without exogenously adding HO.

Cell Membrane and VC MXene-Based Electrochemical Immunosensor with Enhanced Antifouling Capability for Detection of CD44.

The inactive adsorption and interference of biomolecules in electrochemical biosensors is a topic of intense interest. Directly utilizing native cell membranes to endow electrochemical surfaces with antifouling and biocompatible features is a promising strategy, rather than attempting to synthetically replicate complex biological interface properties. In this study, we present a facial and sensitive sandwich-type antifouling immunoassay through platelet membrane/Au nanoparticle/delaminated VC nanosheet (PM/AuNPs/d-VC)-modified electrode as the substrate of sensing interface and methylene blue/aminated metal organic framework (MB@NH-Fe-MOF-Zn) as an electrochemical signal probe.

Nitrogen and sulfur co-doping strategy to trigger the peroxidase-like and electrochemical activity of TiC nanosheets for sensitive uric acid detection.

The development of functional nanomaterials based on the unique structure and morphology of MXene for biosensing has aroused great interest. In this work, using thiourea as the doping source, a new structure composed of nitrogen and sulfur co-doped on the surface of TiC nanosheets was synthesized through a simple one-step synthesis method. Fortunately, the obtained nitrogen and sulfur co-doped TiC nanosheets (NS-TiC NSs) showed excellent peroxidase-like activity and electrochemical activity.

Cell membrane-coated nanoparticles as peroxidase mimetics for cancer cell targeted detection and therapy.

The development of novel and efficient recognition molecules that can be easily modified by nanomaterials to achieve ultra-sensitive and specific cancer cell analysis is of great significance for its early diagnosis and timely prognosis. Herin, a new nanostructured hybrid based on cell membrane-coated Au cores- ultrathin Pt skins composite nanoparticles (Au@Pt@CM NPs) were developed for in vitro detection and treatment of cancer cells. In this strategy, the Au@Pt NPs acted as the signal transducer, and the cell membrane were used as the cancer-cell recognition tool.

Template-Regulated Bimetallic Sulfide Nanozymes with High Specificity and Activity for Visual Colorimetric Detection of Cellular HO.

For the past several decades, most of the research studies on nanozymes have been aimed at improving their catalytic activity and diversity; however, developing nanozymes with strong catalytic activity and great specificity remains a challenge. Herein, a simple and efficient template synthesis method was used to synthesize bimetallic sulfide nanoparticles, NiCoS NPs, and prove that they have excellent peroxidase-like activity with good specificity. By regulating polyvinyl pyrrolidone (PVP) and hexadecyl trimethyl ammonium bromide as the templating agent, we have obtained the NiCoS (PVP) NPs with a high Ni/Co ratio, thus exhibiting superior peroxidase activity.

Single-particle fibrinogen detection using platelet membrane-coated fluorescent polystyrene nanoparticles.

Fibrinogen participates in many physiological processes and is a biomarker for a variety of diseases. On this account, the development of a sensitive method for fibrinogen assay is particularly important. Herein, we demonstrate a new color-coded single-particle detection (SPD) method for fibrinogen detection by using platelet membrane-coated fluorescent polystyrene nanoparticles (PNPs) as the probes.

Excellent humidity sensor based on ultrathin HKUST-1 nanosheets.

The copper-based MOF, HKUST-1 has been applied for humidity sensing owing to hydrophilic ligands and open metal sites which are suitable for sensitively detecting moisture. However, most of the research on the sensor HKUST-1 focuses on the role of the central metal. There are few reports on the morphology-activity relationship of HKUST-1.

Dicer1 promotes Aβ clearance via blocking B2 RNA-mediated repression of apolipoprotein E.

Metabolism of β-amyloid is critical for healthy brain. Decreased clearance of β-amyloid is associated with ensued accumulation of amyloid peptide, culminating in formation of senile plaques, a neuropathological hallmark of Alzheimer's disease(AD). Apolipoprotein E (APOE), a lipoprotein for phospholipid and cholesterol metabolism, is predominantly synthesized by glia in the central nervous system, controlling Aβ aggregation and metabolism.

Brain Dicer1 Is Down-Regulated in a Mouse Model of Alzheimer's Disease Via Aβ42-Induced Repression of Nuclear Factor Erythroid 2-Related Factor 2.

Dicer1 is a microRNA-processing enzyme which plays critical roles in neuronal survival and neuritogenesis. Dicer1 deletion induces neurodegeneration or degeneration in retinal pigment epithelium, which is associated with oxidative stress. Oxidative stress is thought to be central in the pathogenesis of Alzheimer's disease (AD).

Self-Assembling Peptide Artificial Enzyme as an Efficient Detection Prober and Inhibitor for Cancer Cells.

A new hybrid nanoparticle (NP; fluorenylmethoxycarbonyl-arginine-glycine-aspartate and hemin, Fmoc-RGD/hemin NP) was developed for the simultaneous detection and inhibition of breast cancer cells. Hemin can regulate the reactive oxygen species (ROS), while Fmoc-RGD acts as a scaffold for hemin nanocrystallization. Fmoc groups interact with the porphyrin groups of hemin through hydrophobic and π-π interactions to form a hydrophobic core of the NPs.

Intravenous injection of l-aspartic acid β-hydroxamate attenuates choroidal neovascularization via anti-VEGF and anti-inflammation.

Choroidal neovascularization (CNV) is a hallmark of exudative age-related macular degeneration (exAMD) and a major cause of visual loss in AMD. Despite the widespread use of anti-VEGF therapy, serious adverse effects arise from repeated intravitreal injection of anti-VEGF antibodies, which warrant alternative strategy. We report herein that in a CNV murine model created by krypton red laser, intravenous injection of a serine racemase inhibitor, l-Aspartic acid β-hydroxamate (L-ABH), significantly reduced CNV at the dose 6 mg/kg on the first day before and followed by 3 mg/kg on the third day after laser injury.

Seamless Signal Transduction from Three-Dimensional Cultured Cells to a Superoxide Anions Biosensor via In Situ Self-Assembly of Dipeptide Hydrogel.

This study demonstrates a new strategy for the development of a three-dimensional (3D) cell culture model-based cellular biosensing system. Distinctly different from the previously reported layering or separating fabrication of cell culture and sensing devices, herein living cells and enzymes as sensing elements are immobilized into a dipeptide-derived hydrogel matrix through simple one-pot self-assembly. The cells are then 3D cultured in the functional hydrogel, and the releasing superoxide anion (O) is detected in situ by a cascade superoxide dismutase and horseradish peroxidase-based electrochemical biosensor.

Self-Assembled Peptide Hydrogel as a Smart Biointerface for Enzyme-Based Electrochemical Biosensing and Cell Monitoring.

A self-assembled peptide nanofibrous hydrogel composed of N-fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) was used to construct a smart biointerface. This biointerface was then used for enzyme-based electrochemical biosensing and cell monitoring. The Fmoc-FF hydrogel had two functions.