2D-MoS2-supported copper peroxide nanodots with enhanced nanozyme activity: application in antibacterial activity

Peroxidase (POD)-like nanozymes are an upcoming class of new-generation antibiotics that are efficient for broad-spectrum antibacterial action. The POD-like activity employs the generation of reactive oxygen species (ROS), which have been utilized for bactericidal action. However, their intrinsic low catalytic activity and stability limit their bactericidal properties. In this study, we prepared a MoS2-based nanocomposite with copper peroxide nanodots (MoS2@CP) to achieve pH-dependent light-induced nanozyme-based antibacterial action. It has shown superior peroxidase and antibacterial activity at low pH. The mechanism behind the enhanced POD-like activity and high antibacterial activity was established. The mechanistic pathway involves estimating ROS generation, membrane depolarization, inner membrane permeabilization, metal ion release, and the effect of NIR on photothermal and photodynamic activities. Overall, our work highlighted the combinatorial approach for eradicating bacterial infections using enzyme-based antibacterial agents.

Application of Nanozymes and its Progress in the Treatment of Ischemic Stroke

Nanozymes are a new kind of material which has been applied since the beginning of this century, and its birth has promoted the development of chemistry, materials science, and biology. Nanozymes can be used as a substitute for natural enzyme and has a wide range of applications; therefore, it has attracted extensive attention from all sectors of the community, and the number of studies has constantly increasing. In this paper, we introduced the outstanding achievements in the field of nanozymes in recent years from the main function, the construction of nanozyme-based biosensors, and the treatment of ischemic stroke, and we also illustrated the internal mechanism and the catalytic principle. In the end, the obstacles and challenges in the future development of nanozymes were proposed.

Nanozymes towards Personalized Diagnostics: A Recent Progress in Biosensing

This review highlights the recent advancements in the field of nanozymes and their applications in the development of point-of-care biosensors. The use of nanozymes as enzyme-mimicking components in biosensing systems has led to improved performance and miniaturization of these sensors. The unique properties of nanozymes, such as high stability, robustness, and surface tunability, make them an attractive alternative to traditional enzymes in biosensing applications. Researchers have explored a wide range of nanomaterials, including metals, metal oxides, and metal-organic frameworks, for the development of nanozyme-based biosensors. Different sensing strategies, such as colorimetric, fluorescent, electrochemical and SERS, have been implemented using nanozymes as signal-producing components. Despite the numerous advantages, there are also challenges associated with nanozyme-based biosensors, including stability and specificity, which need to be addressed for their wider applications. The future of nanozyme-based biosensors looks promising, with the potential to bring a paradigm shift in biomolecular sensing. The development of highly specific, multi-enzyme mimicking nanozymes could lead to the creation of highly sensitive and low-biofouling biosensors. Integration of nanozymes into point-of-care diagnostics promises to revolutionize healthcare by improving patient outcomes and reducing costs while enhancing the accuracy and sensitivity of diagnostic tools.

Colorimetric and Fluorescence Dual-Mode Biosensors Based on Peroxidase-Like Activity of the Co3O4 Nanosheets

The mimic enzyme has become a research hotspot in recent years because of its advantages of high stability, convenient preparation, and low price. In this article, Co₃O₄ nanosheets synthesized by a simple hydrothermal method possess the characteristics of a peroxidase-like activity. The results demonstrated that 3,3′,5,5′-Tetramethylbenzidine (TMB) could be oxidized by H₂O₂ to produce a typical blue product (oxTMB) which has a strong absorption at 650 nm wavelength with the help of the Co₃O₄ nanosheets. Thus, a simple and sensitive colorimetric detection method for H₂O₂ was established with a good linear relationship (2–200 μM) and a low limit of detection (0.4 μM). Meanwhile, the colorimetric product can effectively quench the fluorescence emitted by Ru(bpy)₃²⁺. Therefore, a colorimetric and fluorescence dual detection mode photochemical sensor for H₂O₂ detection is constructed based on the principle of the inner filter effect (IFE) between the colorimetric product (oxTMB) and Ru(bpy)₃²⁺. It can effectively avoid the false positive problem of a single detection mode. In the presence of glucose oxidase, glucose can be catalyzed to produce gluconic acid and H₂O₂; therefore, the sensor can also be used for the determination of glucose with a good linear relationship (0.02–2 μM) and a low limit of detection (5 nM). Experimental results showed that the sensor has a high sensitivity and strong anti-interference ability which can be used for the detection of actual samples.