Surface-coated magnetic nanostructured materials for robust bio-catalysis and biomedical applications-A review

Green nanobiocatalysts: enhancing enzyme immobilization for industrial and biomedical applications

Nanobiocatalysts (NBCs), which merge enzymes with nanomaterials, provide a potent method for improving enzyme durability, efficiency, and recyclability. This review highlights the use of eco-friendly synthesis methods to create sustainable nanomaterials for enzyme transport. We investigate different methods of immobilization, such as adsorption, ionic and covalent bonding, entrapment, and cross-linking, examining their pros and cons. The decreased environmental impact of green-synthesized nanomaterials from plants, bacteria, and fungi is emphasized. The review exhibits the various uses of NBCs in food industry, biofuel production, and bioremediation, showing how they can enhance effectiveness and eco-friendliness. Furthermore, we explore the potential impact of NBCs in biomedicine. In general, green nanobiocatalysts are a notable progression in enzyme technology, leading to environmentally-friendly and effective biocatalytic methods that have important impacts on industrial and biomedical fields.

Co-immobilization of crosslinked enzyme aggregates on lysozyme functionalized magnetic nanoparticles for enhancing stability and activity

Surface chemistry of carriers plays a key role in enzyme loading capacity, structure rigidity, and thus catalyze activity of immobilized enzymes. In this work, the two model enzymes of horseradish peroxidase (HRP) and glucose oxidase (GOx) are co-immobilized on the lysozyme functionalized magnetic core-shell nanocomposites (LYZ@MCSNCs) to enhance their stability and activity. Briefly, the HRP and GOx aggregates are firstly formed under the crosslinker of trimesic acid, in which the loading amount and the rigidity of the enzyme can be further increased. Additionally, LYZ easily forms a robust anti-biofouling nanofilm on the surface of SiO2@Fe3O4 magnetic nanoparticles with abundant functional groups, which facilitate chemical crosslinking of HRP and GOx aggregates with minimized inactivation. The immobilized enzyme of HRP-GOx@LYZ@MCSNCs exhibited excellent recovery activity (95.6 %) higher than that of the free enzyme (HRP&GOx). Specifically, 85 % of relative activity was retained after seven cycles, while 73.5 % of initial activity was also remained after storage for 33 days at 4 °C. The thermal stability and pH adaptability of HRP-GOx@LYZ@MCSNCs were better than those of free enzyme of HRP&GOx. This study provides a mild and ecofriendly strategy for multienzyme co-immobilization based on LYZ functionalized magnetic nanoparticles using HRP and GOx as model enzymes.

Recent advancement on quantum dot-coupled heterojunction structures in catalysis：A review

Photoelectrocatalysis stands as an exceptionally efficient and sustainable method, significantly addressing both energy scarcity and environmental pollution challenges. Within this realm, quantum dots (QDs) have garnered immense attention for their outstanding catalytic properties. Their unique features-cost-effectiveness, high efficiency, remarkable stability, and exceptional photovoltaic characteristics-set them apart from other tunable semiconductor materials. Heterojunction structures based on quantum dots remarkably boost solar energy conversion efficiency. This review aims to provide a comprehensive overview of the impacts generated by heterojunctions formed using diverse quantum dots and delve into their catalytic applications. Moreover, it sheds light on recent advancements utilizing quantum dots in modifying optoelectronic semiconductor materials for diverse purposes, ranging from hydrogen (H2) generation to carbon and nitrogen reduction, as well as pollutant degradation. Additionally, the paper offers valuable insights into challenges faced by quantum dot applications and outlines promising future prospects.

Electrochemical sensors modified with iron oxide nanoparticles/nanocomposites for voltammetric detection of Pb (II) in water: A review

Permissible limits of Pb2+ in drinking water are being reduced from 10 μgL-1 to 5 μgL-1, which calls for rapid, and highly reliable detection techniques. Electrochemical sensors have garnered attention in detection of heavy metal ions in environmental samples due to their ease of operation, low cost, and rapid detection responses. Selectivity, sensitivity and detection capabilities of these sensors, can be enhanced by modifying their working electrodes (WEs) with iron oxide nanoparticles (IONPs) and/or their composites. Therefore, this review is an in-depth analysis of the deployment of IONPs/nanocomposites in modification of electrochemical sensors for detection of Pb2+ in drinking water over the past decade. From the analyzed studies (n = 23), the optimal solution pH, deposition potential, and deposition time ranged between 3 and 5.6, -0.7 to -1.4 V vs Ag/AgCl, and 100-400 s, respectively. Majority of the studies employed square wave anodic stripping voltammetry (n = 16), in 0.1 M acetate buffer solution (n = 19) for detection of Pb2+. Limits of detection obtained (2.5 x 10-9 - 4.5 μg/L) were below the permissible levels which indicated good sensitivities of the modified electrodes. Despite the great performance of these modified electrodes, the primary source of IONPs has always been commercial iron-based salts in addition to the use of so many materials as modifying agents of these IONPs. This may limit reproducibility and sustainability of the WEs due to lengthy and costly preparation protocols. Steel and/or iron industrial wastes can be alternatively employed in generation of IONPs for modification of electrochemical sensors. Additionally, biomass-based activated carbons enriched with surface functional groups are also used in modification of bare IONPs, and subsequently bare electrodes. However, these two areas still need to be fully explored.

Emerging Trends of Bilirubin Oxidases at the Bioelectrochemical Interface: Paving the Way for Self-Powered Electrochemical Devices and Biosensors

Bilirubin oxidases (BODs) [EC 1.3.3.5 - bilirubin: oxygen oxido-reductase] are enzymes that belong to the multicopper oxidase family and can oxidize bilirubin, diphenols, and aryl amines and reduce the oxygen by direct four-electron transfer from the electrode with almost no electrochemical overpotential. Therefore, BOD is a promising bioelectrocatalyst for (self-powered) biosensors and/or enzymatic fuel cells. The advantages of electrochemically active BOD enzymes include selective biosensing, biocatalysis for efficient energy conversion, and electrosynthesis. Owing to the rise in publications and patents, as well as the expanding interest in BODs for a range of physiological conditions, this Review analyzes scientific literature reports on BOD enzymes and current hypotheses on their bioelectrocatalysis. This Review evaluates the specific research outcomes of the BOD in enzyme (protein) engineering, immobilization strategies, and challenges along with their bioelectrochemical properties, limitations, and applications in the fields of (i) biosensors, (ii) self-powered biosensors, and (iii) biofuel cells for powering bioelectronics.

Surface Modification Strategies for Chrysin-Loaded Iron Oxide Nanoparticles to Boost Their Anti-Tumor Efficacy in Human Colon Carcinoma Cells

Enhancing nanoparticles' anti-cancer capabilities as drug carriers requires the careful adjustment of formulation parameters, including loading efficiency, drug/carrier ratio, and synthesis method. Small adjustments to these parameters can significantly influence the drug-loading efficiency of nanoparticles. Our study explored how chitosan and polyethylene glycol (PEG) coatings affect the structural properties, drug-loading efficiency, and anti-cancer efficacy of Fe3O4 nanoparticles (NPs). The loading efficiency of the NPs was determined using FTIR spectrometry and XRD. The quantity of chrysin incorporated into the coated NPs was examined using UV-Vis spectrometry. The effect of the NPs on cell viability and apoptosis was determined by employing the HCT 116 human colon carcinoma cell line. We showed that a two-fold increase in drug concentration did not impact the loading efficiency of Fe3O4 NPs coated with PEG. However, there was a 33 Å difference in the crystallite sizes obtained from chitosan-coated Fe3O4 NPs and drug concentrations of 1:0.5 and 1:2, resulting in decreased system stability. In conclusion, PEG coating exhibited a higher loading efficiency of Fe3O4 NPs compared to chitosan, resulting in enhanced anti-tumor effects. Furthermore, variations in the loaded amount of chrysin did not impact the crystallinity of PEG-coated NPs, emphasizing the stability and regularity of the system.

Co-based Nanozymatic Profiling: Advances Spanning Chemistry, Biomedical, and Environmental Sciences

Nanozymes, next-generation enzyme-mimicking nanomaterials, have entered an era of rational design; among them, Co-based nanozymes have emerged as captivating players over times. Co-based nanozymes have been developed and have garnered significant attention over the past five years. Their extraordinary properties, including regulatable enzymatic activity, stability, and multifunctionality stemming from magnetic properties, photothermal conversion effects, cavitation effects, and relaxation efficiency, have made Co-based nanozymes a rising star. This review presents the first comprehensive profiling of the Co-based nanozymes in the chemistry, biology, and environmental sciences. The review begins by scrutinizing the various synthetic methods employed for Co-based nanozyme fabrication, such as template and sol-gel methods, highlighting their distinctive merits from a chemical standpoint. Furthermore, a detailed exploration of their wide-ranging applications in biosensing and biomedical therapeutics, as well as their contributions to environmental monitoring and remediation is provided. Notably, drawing inspiration from state-of-the-art techniques such as omics, a comprehensive analysis of Co-based nanozymes is undertaken, employing analogous statistical methodologies to provide valuable guidance. To conclude, a comprehensive outlook on the challenges and prospects for Co-based nanozymes is presented, spanning from microscopic physicochemical mechanisms to macroscopic clinical translational applications.

Magnetic Nanoparticles: A Review on Synthesis, Characterization, Functionalization, and Biomedical Applications

Nowadays, magnetic nanoparticles (MNPs) are applied in numerous fields, especially in biomedical applications. Since biofluidic samples and biological tissues are nonmagnetic, negligible background signals can interfere with the magnetic signals from MNPs in magnetic biosensing and imaging applications. In addition, the MNPs can be remotely controlled by magnetic fields, which make it possible for magnetic separation and targeted drug delivery. Furthermore, due to the unique dynamic magnetizations of MNPs when subjected to alternating magnetic fields, MNPs are also proposed as a key tool in cancer treatment, an example is magnetic hyperthermia therapy. Due to their distinct surface chemistry, good biocompatibility, and inducible magnetic moments, the material and morphological structure design of MNPs has attracted enormous interest from a variety of scientific domains. Herein, a thorough review of the chemical synthesis strategies of MNPs, the methodologies to modify the MNPs surface for better biocompatibility, the physicochemical characterization techniques for MNPs, as well as some representative applications of MNPs in disease diagnosis and treatment are provided. Further portions of the review go into the diagnostic and therapeutic uses of composite MNPs with core/shell structures as well as a deeper analysis of MNP properties to learn about potential biomedical applications.

Recent Advances in Nanowire-Based Wearable Physical Sensors

Wearable electronics is a technology that closely integrates electronic devices with the human body or clothing, which can realize human-computer interaction, health monitoring, smart medical, and other functions. Wearable physical sensors are an important part of wearable electronics. They can sense various physical signals from the human body or the surrounding environment and convert them into electrical signals for processing and analysis. Nanowires (NW) have unique properties such as a high surface-to-volume ratio, high flexibility, high carrier mobility, a tunable bandgap, a large piezoresistive coefficient, and a strong light-matter interaction. They are one of the ideal candidates for the fabrication of wearable physical sensors with high sensitivity, fast response, and low power consumption. In this review, we summarize recent advances in various types of NW-based wearable physical sensors, specifically including mechanical, photoelectric, temperature, and multifunctional sensors. The discussion revolves around the structural design, sensing mechanisms, manufacture, and practical applications of these sensors, highlighting the positive role that NWs play in the sensing process. Finally, we present the conclusions with perspectives on current challenges and future opportunities in this field.

Review of covalent organic frameworks for enzyme immobilization: Strategies, applications, and prospects

Efficient enzyme immobilization systems offer a promising approach for improving enzyme stability and recyclability, reducing enzyme contamination in products, and expanding the applications of enzymes in the biomedical field. Covalent organic frameworks (COFs) possess high surface areas, ordered channels, optional building blocks, highly tunable porosity, stable mechanical properties, and abundant functional groups, making them ideal candidates for enzyme immobilization. Various COF-enzyme composites have been successfully synthesized, with performances that surpass those of free enzymes in numerous ways. This review aims to provide an overview of current enzyme immobilization strategies using COFs, highlighting the characteristics of each method and recent research applications. The future opportunities and challenges of enzyme immobilization technology using COFs are also discussed.

Boosting the integration of cell membrane-nanomaterial hybrids via dextran-mediated dynamic dispersion system to capture bioactive compounds in natural products

Efficient integration is a prerequisite for the application of cell membrane-nanomaterial hybrids (CN hybrids) in bioanalysis, however, the poor dispersity of nanomaterials limits the development of this technology. Although the traditional hydrophilic modification method could improve the dispersity of nanomaterials, it would hinder the coating of the cell membrane, thus making it unsuitable for the integration of CN hybrids. Herein, a method has been proposed to improve the integration efficiency of CN hybrids from a different perspective, that is, establishing a dynamic dispersion system to enhance the interfacial interaction between cell membranes and nanomaterials. Specifically, magnetic graphene oxide (MGO) nanosheets were used as the model carrier and HepG2 cells were used as the source for membrane coating. The addition of the macromolecular stabilizer dextran to the integration process enhanced the dispersity of MGO and avoided the resistance to membrane coating caused by surface modification. Intriguingly, MGO in the dynamic dispersion system showed superior membrane coating ability as compared to hydrophilic modification methods, resulting in the more efficient integration of CN hybrids and greater sensitivity in capturing bioactive compounds from natural products. The proposed design principle provides a brand-new perspective for optimizing the behavior of CN hybrids and can improve the effectiveness of CN hybrids in bioanalytical applications.

Nanomaterial Constructs for Catalytic Applications in Biomedicine: Nanobiocatalysts and Nanozymes

Nanomaterials possess superior advantages due to their special geometries, higher surface area, and unique mechanical, optical, and physicochemical properties. Their characteristics make them great contributors to the development of many technological and industrial sectors. Therefore, novel nanomaterials have an increasing interest in many research areas including biomedicine such as chronic inflammations, disease detection, drug delivery, and infections treatment. Their relevant role is, in many cases, associated with an effective catalytic application, either as a pure catalyst (acting as a nanozyme) or as a support for catalytically active materials (forming nanobiocatalysts). In this review, we analyze the construction of nanozymes and nanobiocatalyst by different existing forms of nanomaterials including carbon-based nanomaterials, metal-based nanomaterials, and polymer-based nanocomposites. Then, we examine successful examples of such nanomaterials employed in biomedical research. The role played by nanomaterials in catalytic applications is analyzed to identify possible research directions toward the development of the field and the achievement of real practicability.

Graphical Abstract

Protein C-Terminal Tyrosine Conjugation via Recyclable Immobilized BmTYR

Protein modification plays an essential role in biological and pharmaceutical research. Due to the ordinary selectivity and inevitable damage to proteins of chemical synthetic methods, increased efforts were focused on biocatalysts which exhibited high regioselectivity and mild reaction conditions. However, separation of the biocatalysts and modified proteins remained a problem, especially when scaling up. Here, we developed a simple method for site-specific protein modification with a recyclable biocatalyst. The immobilizing tyrosinase (BmTYR) on magnetic beads can oxidize C-terminal tyrosine residues of the target protein to o-quinone, followed by the spontaneous addition of different nucleophiles (e.g., aniline derivatives), resulting in a C-terminal modified protein. Compared to the homogeneous biocatalytic system reported before, this heterogeneous system leads to an easier separation. Furthermore, the solid-phase biocatalyst can be regenerated during separation, providing reusability and lower costs.

Advances in Metal-Organic Framework (MOFs) based biosensors for diagnosis: An update

Metal-organic frameworks (MOFs) have significant advantages over other candidate classes of chemo-sensory materials owing to their extraordinary structural tunability and characteristics. MOF-based biosensing is a simple, and convenient method for identifying various species. Biomarkers are molecular or cellular processes that link environmental exposure to a health outcome. Biomarkers are important in understanding the links between environmental chemical exposure and the development of chronic diseases, as well as in identifying disease-prone subgroups. Until now, several species, including nanoparticles (NPs) and their nanocomposites, small molecules, and unique complex systems, have been used for the chemical sensing of biomarkers. Following the overview of the field, we discussed the various fabrication methods for MOFs development in this review. We provide a thorough overview of the previous five years of progress to broaden the scope of analytes for future research. Several enzymatic and non-enzymatic sensors are offered, together with a mandatory measuring method that includes detection range and dynamic range. In addition, we reviewed the comparison of enzymatic and non-enzymatic biosensors, inventive edges, and the difficulties that need to be solved. This work might open up new possibilities for material production, sensor development, medical diagnostics, and other sensing fields.