Besides the pandemic caused by the coronavirus outbreak, many other pathogenic microbes also pose a devastating threat to human health, for instance, pathogenic bacteria. Due to the lack of ...broad‐spectrum antibiotics, it is urgent to develop nonantibiotic strategies to fight bacteria. Herein, inspired by the localized “capture and killing” action of bacteriophages, a virus‐like peroxidase‐mimic (V‐POD‐M) is synthesized for efficient bacterial capture (mesoporous spiky structures) and synergistic catalytic sterilization (metal–organic‐framework‐derived catalytic core). Experimental and theoretical calculations show that the active compound, MoO3, can serve as a peroxo‐complex‐intermediate to reduce the free energy for catalyzing H2O2, which mainly benefits the generation of •OH radicals. The unique virus‐like spikes endow the V‐POD‐M with fast bacterial capture and killing abilities (nearly 100% at 16 µg mL–1). Furthermore, the in vivo experiments show that V‐POD‐M possesses similar disinfection treatment and wound skin recovery efficiencies to vancomycin. It is suggested that this inexpensive, durable, and highly reactive oxygen species (ROS) catalytic active V‐POD‐M provides a promising broad‐spectrum therapy for nonantibiotic disinfection.
A bioinspired, spiky, and highly catalytic‐active virus‐like peroxidase‐mimic (V‐POD‐M) is synthesized for the localized “capture and killing” eradication of pathogenic bacteria. Experimental and theoretical calculations demonstrate that the V‐POD‐M exhibits strong bacterial interactions and efficient capture, synergistic catalytic sterilization, and similar in vivo disinfection efficiency to that of vancomycin, which provides a promising broad‐spectrum therapy for nonantibiotic disinfection.
Electrochemical sensors play a significant role in detecting chemical ions, molecules, and pathogens in water and other applications. These sensors are sensitive, portable, fast, inexpensive, and ...suitable for online and in-situ measurements compared to other methods. They can provide the detection for any compound that can undergo certain transformations within a potential window. It enables applications in multiple ion detection, mainly since these sensors are primarily non-specific. In this paper, we provide a survey of electrochemical sensors for the detection of water contaminants, i.e., pesticides, nitrate, nitrite, phosphorus, water hardeners, disinfectant, and other emergent contaminants (phenol, estrogen, gallic acid etc.). We focus on the influence of surface modification of the working electrodes by carbon nanomaterials, metallic nanostructures, imprinted polymers and evaluate the corresponding sensing performance. Especially for pesticides, which are challenging and need special care, we highlight biosensors, such as enzymatic sensors, immunobiosensor, aptasensors, and biomimetic sensors. We discuss the sensors' overall performance, especially concerning real-sample performance and the capability for actual field application.
The applications of nanomaterial‐based enzyme‐mimics (Enz‐Ms) in biocatalytically therapeutic and diagnostic fields have attracted extensive attention. The regulation of the biocatalytic performances ...and biofunctionalities of Enz‐Ms are essential research objectives, including the rational design and synthesis of Enz‐Ms with desired biofunctional molecules and nanostructures, especially at the level of molecules and even single atoms. Here, this timely progress report provides pivotal advances and comments on recent researches on engineering biofunctional Enz‐Ms (BF/Enz‐Ms), particularly chemical synthesis, functionalization strategies, and integration of diverse enzyme‐mimetic catalytic activities of BF/Enz‐Ms. First, the definitions and catalogs of BF/Enz‐Ms are briefly introduced. Then, detailed comments and discussions are provided on the fabrication protocols, biocatalytic properties, and therapeutic/diagnostic applications of engineered BF/Enz‐Ms via hydrogels, nanogels, metal–organic frameworks, metal–polyphenol networks, covalent–organic frameworks, functional cell membranes, bioactive molecules and polymers, and composites. Finally, the future perspectives and challenges on BF/Enz‐Ms are outlined and thoroughly discussed. It is believed that this progress report will give a chemical and material overview on the state‐of‐the‐art designing principles of BF/Enz‐Ms, thus further promoting their future developments and prosperities for a wide range of applications.
Recent research on engineered biofunctional enzyme mimics (BF/Enz‐Ms) for catalytic therapeutics and diagnostics are reviewed. The fabrication protocols, biocatalytic properties, and therapeutic/diagnostic applications of engineered BF/Enz‐Ms via hydrogels, nanogels, metal–organic frameworks, metal–polyphenol networks, covalent–organic frameworks, functional cell membranes, bioactive molecules and polymers, and composites are discussed in detail. This review will inspire and promote the design of future state‐of‐the‐art BF/Enz‐Ms.
The microenvironments with high reactive-oxygen-species (ROS) levels, inflammatory responses, and oxidative-stress effects in diabetic ulcer wounds, leading to poor proliferation and differentiation ...of stem cells, severely inhibit their efficient healing. Here, to overcome the unbalanced multielectron reactions in ROS catalysis, we develop a cobalt selenide-based biocatalyst with an amorphous Ru@CoSe nanolayer for ultrafast and broad-spectrum catalytic ROS-elimination. Owing to the enriched electrons and more unoccupied orbitals of Ru atoms, the amorphous Ru@CoSe nanolayer-equipped biocatalyst displays excellent catalase-like kinetics (maximal reaction velocity, 23.05 μM s
; turnover number, 2.00 s
), which exceeds most of the currently reported metal compounds. The theoretical studies show that Ru atoms act as "regulators" to tune the electronic state of the Co sites and modulate the interaction of oxygen intermediates, thus improving the reversible redox properties of active sites. Consequently, the Ru@CoSe can efficiently rescue the proliferation of mesenchymal stem cells and maintain their angiogenic potential in the oxidative stress environment.
experiments reveal the superior ROS-elimination ability of Ru@CoSe on the inflammatory diabetic wound. This study offers an effective nanomedicine for catalytic ROS-scavenging and ultrafast healing of inflammatory wounds and also provides a strategy to design biocatalytic metal compounds
bringing amorphous catalytic structures.
Growing concerns about pesticide residues in agriculture are pushing the scientific community to develop innovative and efficient methods for detecting these substances at low concentrations down to ...the molecular level. In this context, surface-enhanced Raman spectroscopy (SERS) is a powerful analytical method that has so far already undergone some validation for its effectiveness in pesticide detection. However, despite its great potential, SERS faces significant difficulties obtaining reproducible and accurate pesticide spectra, particularly for some of the most widely used pesticides, such as malathion, chlorpyrifos, and imidacloprid. Those inconsistencies can be attributed to several factors, such as interactions between pesticides and SERS substrates and the variety of substrates and solvents used. In addition, differences in the equipment used to obtain SERS spectra and the lack of standards for control experiments further complicate the reproducibility and reliability of SERS data. This review systematically discusses the problems mentioned above, including a comprehensive analysis of the challenges in precisely evaluating SERS spectra for pesticide detection. We not only point out the existing limitations of the method, which can be traced in previous review works, but also offer practical recommendations to improve the quality and comparability of SERS spectra, thereby expanding the potential applications of the method in such an essential field as pesticide detection.
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•SERS holds a promise for rapid, selective, sensitive onsite pesticide detection.•Reported Raman spectra of malathion, chlorpyrifos, imidacloprid are very consistent.•Reported SERS spectra of the same pesticides are extremely variable.•SERS spectra variability can be explained by multiple mechanisms.•Systematic approach is needed to achieve analytical standards.
Gallium selenide (GaSe) is a layered semiconductor and a well-known nonlinear optical crystal. The discovery of graphene has created a new vast research field focusing on two-dimensional materials. ...We report on the nonlinear optical properties of few-layer GaSe using multiphoton microscopy. Both second- and third-harmonic generation from few-layer GaSe flakes were observed. Unexpectedly, even the peak at the wavelength of 390 nm, corresponding to the fourth-harmonic generation or the sum frequency generation from third-harmonic generation and pump light, was detected during the spectral measurements in thin GaSe flakes.
Raman spectroscopy (RS) is the tool of choice for the analysis of carbon nanomaterials. In graphene and carbon nanotubes (CNT), RS provides rich information such as defect concentration, CNT ...chirality, graphene layer number, doping, strain, and other physical parameters of interest. This work presents the RS investigation of a semiconducting CNT film after high power laser irradiation. Changes were observed in the D band revealing the change in the defect concentration induced by the laser. More importantly, it was found the relative intensity decrease of G− and some radial breathing modes which suggests that the effects of laser irradiation induce diameter‐selective effects in CNTs. The spectroscopic changes to the selective electronic structure modification for some semiconducting CNTs were attributed as due to those CNTs getting closer to resonance conditions with the fixed laser excitation.
Laser irradiation on a single‐walled carbon nanotube film is studied. Hyperspectral Raman imaging allows to investigate a single‐irradiated spot and to elucidate the selective CNT modifications.
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