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Vitamin D deficiency or insufficiency is a growing public health problem. In this work, a novel and sample approach based on microcantilever for measuring the level of 25-hydroxyvitamin D (25(OH)D) was proposed. The Bruno aptamer was utilized to functionalize the microcantilevers, serving as a sensing layer for detecting 25(OH)D. The working principle of the sensor is based on the changes of the microcantilever deflection and frequency as a result of the aptamer removal from the surface of the microcantilever resulting from its interaction with vitamin D. The results showed a linear dependence between vitamin D concentration and the microcantilever deflection and frequency shift in a range of concentrations from 1 to 300 nM. For this biosensor, the limit of detection (LOD) was calculated to be ∼ 0.3 nM. The biosensor selectivity was tested against vitamin C and the sensor showed high selectivity towards vitamin D.

The removal of dyes from wastewater that are released during industrial processes has become a significant concern in the environmental science in recent years. To tackle this issue, researchers are exploring the use of nanomaterials for designing new adsorbents. Another promising approach is to grow polymer brushes with high density functional groups via surface-initiated atom transfer radical polymerization (SI-ATRP), which can significantly enhance their ability to absorb dyes. The presence of carboxylic acid groups on the adsorbent material significantly contributes to its efficacy in dye removal by enhancing adsorption capacity, enabling selective adsorption, pH-dependent behavior, chelation, or complexation, and providing stability for repeated usage. In this work, a nanomaterial of carboxylic functionalized poly (methacrylic acid 2-(tert-butylamino)ethyl ester)-coated mesoporous silica nanoparticles (MSNPs–PMATBAE–COOH) was synthesized by the growth of PTBAEMA via surface-initiated atom-transfer radical polymerization, then reacted with succinic anhydride reaction. The chemical structure of MSNPs–PMATBAE–COOH was confirmed using multiple methods, including FT-IR and DLS, and the core-brush morphology was observed clearly using TEM. MSNPs–PMATBAE–COOH were subsequently employed to adsorb hazardous dyes efficiently. The anionic polymer brushes enabled the adsorption of methylene blue (MB) and tetraethylrhodamine (TER) at optimum pH value of 3. The results also indicated that MSNPs–PMATBAE–COOH possessed significant adsorption capacity (263.4 and 212.9 mg g−1 for MB and TER, respectively) and fast adsorption rate (within 15 min), which can be explained by the abundance of adsorptive polymer brushes and the small size of the nanoparticles. Overall, the findings indicate that MSNPs-PMATBAE-COOH is a highly effective adsorbent material for eliminating dye pollutants from wastewater.

Contamination of heavy metal (Cd2+ & Pb2+) ions in drinking water is producing major impacts on the environment and public health and is considered one of the greatest dangers to humanity. Membrane technology has been chosen over other processing methods due to its simplicity and high capacity for more effective removal of hazardous heavy metals. In the current study, amine, thiol, and bi-thiol functional groups were used to functionalize mesoporous silica nanoparticles (MSNs) to improve the efficiency of the silica nanoparticle. The morphology of the MSNs as well as the existence of amine and thiol on the surface of MSNs was demonstrated by a variety of characterization techniques, including FTIR, TEM, and SEM examination. The impact of surface-modified MSNs on the morphology, properties, and performance of polysulfone (PS) nanofiltration (NF) membranes was also evaluated. The membrane that incorporated amine with thiol-based MSNs (DiMP-MSNs/PS-NF membrane) had the highest pure water permeability (6.7 LMH bar−1). As a result of the functional groups, the surface-modified MSNs/PS nanofiltration are extremely effective at removing heavy metal ions from aqueous solutions. The surface-modified MSNs/PS nano-filtration membranes exhibit unprecedented Cd2+ and Pb2+ removal rates of approximately 82% and 99%, respectively. This research indicates the possible application of the surface-modified MSNs/PS nanofiltration membrane as a promising platform to remove heavy metal ions from polluted water.

This work presents the preparation of mesoporous silica nanoparticles (MSNs) using Stöber process. Then, the MSNs surface was modified with propyl thiol, followed by conversion of thiol to sulfonic acid using H2O2, acetic acid/H2O2, HNO3/H2O2, and H2SO4/H2O2. Surface modified MSNs were characterized by a variety of techniques: the Brunauer, Emmett and Teller (BET) technique, thermogravimetric analysis (TGA), scanning and transmission electron microscopies (SEM and TEM), dynamic light scattering (DLS) and Fourier-transform infrared spectroscopy (FTIR). The size of unmodified and modified MSNs ranged between 200 and 320 nm, with pore size of ca. 5.0 nm and surface area ca. 900 m2/g. The surface zeta potential was of the fabricated nanomaterials was estimated to be between −35 and −43 mV. When the surface modified MSNs were subjected to esterification reaction between heptanol and acetic acid, the conversion to ester reached 75% in the presence of MSNs-Pr-SO3H (via H2SO4/H2O2), comparing to MSNs-Pr-SO3H (via H2O2) or MSNs-Pr-SO3H (via Ac/H2O2). The conversion increased 75% to 93% for MSNs-Pr-SO3H (via H2SO4/H2O2) when the temperature increased from 90 °C to 110 °C, respectively.

Waste effluents of textiles and leather industries are seriously causing numerous health problems. Organic dyes are one of the major contaminants of industrial wastewater. Adsorption techniques can be used effectively to remove organic dyes and treat water for human consumption. In this work, we reported a rational multistep synthesis of mesoporous silica nanoparticles (MSNs) with selectively generated active inner/external surfaces. The functional groups were incorporated into the silica surface using a combination of co-condensation and post-grafting procedures. Both amine and sulfonic acid functional groups were used to produce a total coffer of MSNs inner/outer surface by amino or sulfonic moiety denoted as [N-MSNs]-N and [S-MSNs]-S, respectively. Furthermore, bifunctional groups were also synthesised by coffering the MSNs outer surface by sulfonic acid functional groups and the inner surface with amino functional groups or vice-versa denoted as [N-MSNs]-S and [S-MSNs]-N, respectively. The efficiency of the multiple grafting strategies was evaluated for the removal of cationic dye (methylene blue (MB)) from contaminated water samples using batch method mode. The physical adsorption parameters such as pH, initial concentrations of MB, exposure time and the effect of salt concentration was examined. Moreover, the adsorption kinetic models: pseudo first order, pseudo second order and interparticle diffusion were also applied for the collected data. The highest adsorption performance was accomplished by [N-MSNs]-S sorbent with 98% extraction efficiency, whereas the lowest adsorption efficiency was observed for [N-MSNs]-N sorbent. Increasing the electrolyte concentration had led to an increase in the adsorption efficiency of all nanomaterials containing sulfonic acid. An excellent extraction efficiency was obtained when the materials were applied to spiked real water samples. These adsorbents are promising for the removal of MB from wastewater on account of their high adsorption capacity and for their resistance to the presence of other unavoidable anions in the wastewater.

A number of new substances were included into the (5Z)-5-[(2-piperidinequinoline-3-yl)methyl]-2-chloroquinoline structural framework. The condensation process 2-chloroquinoline, which served as a crucial reagent in the reaction with 3-carbaldehydes to produce 2,4-thiazolidinedione, allowed for the production of 1,3-thiazolidine-2,4-dione. The newly developed substances were described by means of their reactions with halide compounds, particularly those pertaining to substituted N-alkylation. Elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance spectroscopy ( 1 H NMR) were used to identify the chemical. Furthermore, the antibacterial activity of the produced compounds was evaluated in vitro against a range of pathogens, including Bacillus subtilis, and Escherichia coli. Moreover, docking experiments were conducted using the PDF enzyme of E. coli to improve our understanding of the binding mechanism between the synthesized 5(A-N) compounds and the enzyme., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, we present a convenient approach utilizing gold nanostructures coated cellulose membrane for the quantification of uric acid in an aqueous solution. The synthesis of system was achieved by functionalizing cellulose membrane with poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PMETAC) and cross-linked with ethylene glycol dimethacrylate (EGDMA). FT-IR and XPS confirm the formation of PMETAC and PMETAC/EGDMA on the cellulose. The fabricated substrates were exposed to tetrachloroaurate solution, then reduced by NaBH 4 . We have systematically investigated the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (H 2 O 2 ) in various pH conditions, absent uric acid, using the fabricated substrates. The colorimetric response-observed through UV-Vis spectroscopy-revealed significant shifts in absorbance at 660 nm, correlating with uric acid concentrations across a range of pH levels. The films exhibited a pronounced color change from green to light yellow in basic to neutral environments and from yellow to dark green under more acidic conditions, demonstrating their potential for high-sensitivity uric acid detection. The assessment of the catalytic films' reusability and stability revealed insights into their enduring performance, identifying opportunities for enhancing material design and functionality for extended applications. This study not only underscores the films' versatile detection capabilities but also emphasizes the importance of pH in tuning the assay's sensitivity and specificity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)