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Pharmaceutical pollutants such as tetracycline (TC) pose a growing global threat to aquatic and terrestrial biodiversity. Developing new methods for the degradation of these pollutants would be a significant advancement in their management. The progress in the development of synthetic enzymes based on nanomaterials has resulted in their replacement for natural enzymes with higher performance quality. In this work, a magnetite/Gd3+/β-cyclodextrin nanoplatform was prepared and used for TC degradation for the first time. The characterization studies were carried out using various methods, including SEM, XRD, and FTIR. The peroxidase-mimic activity of the synthesized nanoplatform was evaluated using a colorimetric assay. Kinetic parameters, including Km and Vmax, were obtained using TMB (3,3′,5,5′-tetramethylbenzidine) and H2O2. The results indicated that prepared particles had a lower Km value than horseradish peroxidase (HRP), which confirmed the higher affinity of the prepared nanoplatform toward its substrates. We also demonstrated that our recyclable nanoplatform (3 mg/mL) was able to degrade 82% of TC (4.5 mM) in 85 min without any initiator such as light or ultrasonic waves. Collectively, these results confirmed the high affinity of the synthesized nanoplatform toward desired substrates, including TC.

Establishing enzyme-free sensing assays with great selectivity and sensitivity for glucose and H2O2 detection has been highly required in biological science. In particular, the exploitation of nanomaterials by using noble metals of high conductivity and surface area has been widely investigated to act as selective catalytic agents for molecular recognition in sensing platforms. Several approaches for a straightforward, speedy, selective, and sensitive recognition of glucose and H2O2 were requested. This paper reviews the current progress in electrochemical detection using metal–organic frameworks (MOFs) for H2O2 and glucose recognition. We have reviewed the latest electrochemical sensing assays for in-place detection with priorities including straightforward procedure and manipulation, high sensitivity, varied linear range, and economic prospects. The mentioned sensing assays apply electrochemical systems through a rapid detection time that enables real-time recognition. In profitable fields, the obstacles that have been associated with sample preparation and tool expense can be solved by applying these sensing means. Some parameters, including the impedance, intensity, and potential difference measurement methods have permitted low limit of detections (LODs) and noticeable durations in agricultural, water, and foodstuff samples with high levels of glucose and H2O2.

In this study, graphitic carbon nitride (g-C3N4)-based ZnO heterostructure was synthesized using a facile calcination method with urea and zinc nitrate hexahydrate as the initiators. According to the scanning electron microscopic (SEM) images, spherical ZnO particles can be seen along the g-C3N4 nanosheets. Additionally, the X-ray diffraction (XRD) analysis reveals the successful synthesis of the g-C3N4/ZnO. The photocatalytic activity of the synthesized catalyst was tested for the decolorization of crystal violet (CV) as an organic refractory contaminant. The impacts of ZnO molar ratio, catalyst amount, CV concentration, and H2O2 concentration on CV degradation efficiency were investigated. The obtained outcomes conveyed that the ZnO molar ratio in the g-C3N4 played a prominent role in the degradation efficiency, in which the degradation efficiency reached 95.9% in the presence of 0.05 mmol of ZnO and 0.10 g/L of the catalyst in 10 mg/L of CV through 120 min under UV irradiation. Bare g-C3N4 was also tested for dye decolorization, and a 76.4% dye removal efficiency was obtained. The g-C3N4/ZnO was also tested for adsorption, and a 32.3% adsorption efficiency was obtained. Photocatalysis, in comparison to adsorption, had a dominant role in the decolorization of CV. Lastly, the results depicted no significant decrement in the CV degradation efficiency in the presence of the g-C3N4/ZnO photocatalyst after five consecutive runs.

Mathematical and computational models are used to describe biomechanical processes in multicellular systems. Here, we develop a model to analyse how two types of epithelial cell layers interact during tissue invasion depending on their cellular properties, i.e., simulating cancer cells expanding into a region of normal cells. We model the tissue invasion process using the cellular Potts model and implement our two-dimensional computational simulations in the software package CompuCell3D. The model predicts that differences in mechanical properties of cells can lead to tissue invasion, even if the division rates and death rates of the two cell types are the same. We also show how the invasion speed varies depending on the cell division and death rates and the mechanical properties of the cells.

In this paper, a facile hydrothermal approach was used to integrate graphitic carbon nitride dots (CNDs) with hetaerolite (ZnMn2O4) at different weight percentages. The morphology, microstructure, texture, electronic, phase composition, and electrochemical properties were identified by field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), ultraviolet-visible diffuse reflectance (UV-vis DR), photoluminescence (PL), electrochemical impedance spectroscopy (EIS), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), and photocurrent density. The results of XRD, FT-IR, EDX, and XPS analyses confirmed the synthesis of CNDs/ZnMn2O4 (20%) nanocomposite. As per PL, EIS, and photocurrent outcomes, the binary CNDs/ZnMn2O4 nanocomposite revealed superior features for interfacial transferring of charge carriers. The developed p–n heterojunction at the interface of CNDs and ZnMn2O4 nanoparticles partaken a significant role in the impressive charge segregation and migration. The binary nanocomposites were employed for the photodegradation of several dye pollutants, including rhodamine B (RhB), fuchsin, malachite green (MG), and methylene blue (MB) at visible wavelengths. Amongst the fabricated photocatalysts, the CNDs/ZnMn2O4 (20%) nanocomposite gave rise to about 98% RhB degradation efficiency within 45 min with the rate constant of 747 × 10−4 min−1, which was 66.5-, 3.44-, and 2.72-fold superior to the activities of CN, CNDs, and ZnMn2O4 photocatalysts, respectively. The impressive photodegradation performance of this nanocomposite was not only associated with the capacity for impressive visible-light absorption and boosted separation and transport of charge carriers, but also with its large surface area.

Anion exchange membrane water electrolysis (AEMWE) has great potential to be established as a highperformance and low-capital cost technology for hydrogen production. High current densities can be achieved with a non-platinum group metal (non-PGM) catalyst. However, the harsh operation conditions require stable cell components. Here, we report on the use of a highly stable and ion conductive poly(fluorene alkylene) membrane (PdF–TMA) tethered with trimethylammonium cations via phenylpropyl side chains for AEMWE cells operating with 2 M aqueous KOH. The ether-free PdF–TMA polymer is efficiently prepared by polyhydroxyalkylation to reach a molecular weight of 236 kDa, a high thermal stability, and an ion-exchange capacity of 2.14 mequiv. g−1 (OH− form). Using commercial electrodes of NiFe2O4 (anode) and RANEY® nickel (cathode) and PdF–TMA as an AEM, the output current reached 1 A cm−2 at voltages below 1.9 V at 60 °C. Also, PdF–TMA outperformed AEMION™ in terms of membrane resistance by almost 30% and, after 100 h at 0.5 A cm−2, did not reveal any loss of conductivity, in contrast to AEMION™. Furthermore, both membranes were analysed by ¹H NMR spectroscopy after AEMWE tests and the PdF–TMA proved very stable even at 80 °C. [ABSTRACT FROM AUTHOR]