Surface Reactive Groups Research Articles

Triggering Long Persistent Luminescence From Functionalizable Carbon Dots‐in‐Carbon Nitrides Composites Via Production of Deep‐Traps

AbstractDispersible and functionalizable long persistent luminescent (LPL) materials are highly desired for flexible use of LPL in various fields. However, synthesizing metal‐free LPL systems with stable long‐lived intermediates and reactive surface groups, which are key requirements for robust LPL and the ability to be functionalized, has proven to be challenging. Herein, the microwave‐assisted preparation of carbon dots (CDs)‐based LPL materials is demonstrated with abundant surface amino groups via in situ embedding of CDs into carbon nitrides (CNs). The incorporation of CDs leads to the formation of deep traps and promotes exciton transmission between CDs and trap states, contributing to the generation of LPL. By varying the embedded CDs, tunable LPL ranging from blue to yellow can be achieved, with a duration exceeding 10 min. Due to the covalent bonding between CDs and CNs, the materials (named CDs@CNs) exhibit robust LPL under ambient conditions and evenly dispersed in water through ultrasonic treatment. Furthermore, the surface amino groups serve as sites for further modification, allowing for on‐demand performance design and control, such as adjustable hydrophilicity–hydrophobicity for various applications. This work provides new insights into designing superior flexible CDs‐based LPL materials and expanding the domain of metal‐free LPL materials.

Multilayer Ti3C2-CNTs-Au Loaded with Cyclodextrin-MOF for Enhanced Selective Detection of Rutin.

In this work, multi-layer Ti3C2 - carbon nanotubes - gold nanoparticles (Ti3C2-CNTs-Au) and cyclodextrin metal-organic framework - carbon nanotubes (CD-MOF-CNTs) have been prepared by in situ growth method and used to construct the ultra-sensitive rutin electrochemical sensor for the first time. Among them, the large number of metal active sites of Ti3C2, the high electron transfer efficiency of CNTS, and the good catalytic properties of AuNPs significantly enhance the electrochemical properties of the composite carbon nanomaterials. Interestingly, CD-MOF has a unique host-guest recognition and a large number of cavities, molecular gaps, and surface reactive groups, which gives the composite outstanding accumulation properties and selectivity for rutin. Under the optimized conditions, the constructed novel sensor has satisfactory detection performance for rutin in the range of 2 × 10-9 to 8 × 10-7M with a limit of detection of 6.5 × 10-10M. In addition, the sensor exhibits amazing anti-interference performance against rutin in some flavonoid compounds and can be used to test natural plant samples (buckwheat, Cymbopogon distans, and flos sophorae immaturus). This work has promising applications in the field of environmental and food analysis, and exploring new directions for the application of Mxene-based composites.

Effect of Protein Surface Hydrophobicity and Surface Amines on Soy Adhesive Strength.

Soy is considered one of the most promising natural materials for manufacturing wood adhesives due to its low cost, high protein content, and ready availability. However, more cost-effective ways of improving its wet shear strength are needed to achieve wider market acceptance. Protein adhesive wet strength depends on the use of (typically expensive) crosslinking additives as well as the processing/denaturation of the protein. It has been commonly stated in the literature that protein denaturation leads to higher bond strength by activating the surface and exposing the reactive groups. Therefore, we investigated how differences in surface reactive groups (surface hydrophobicity and reactive amine groups) brought on with different denaturation treatments relate to bonding performance. Fourteen soy protein isolates (SPIs) with different denaturation histories were investigated. Characterization of the SPIs included surface hydrophobicity, surface amine content, extent of protein hydrolysis, and bond strength (wet and dry, with and without polyamidoamine epichlorohydrin (PAE) crosslinking agent) by ASTM D7998. The molecular weight patterns showed that proteins denatured by extensive hydrolysis had very low bond strengths. Adding the crosslinker, PAE, improved all the shear strength values. We found that the number of water-accessible reactive amine groups on protein surfaces had no impact on the adhesive strength, even with the amine-reactive crosslinker, PAE. Conversely, increased surface hydrophobicity was beneficial to adhesive strength in all cases, though this correlation was only statistically significant for wet strength without PAE. While, in general, denatured proteins are typically thought to form better bonds than native state proteins, this work suggests that it matters how proteins are denatured, and what surfaces become exposed. Denaturation by hydrolysis did not improve bond strength, and extensive hydrolysis seemed highly detrimental. Moreover, exposing hydrophobic surface groups was beneficial, but exposing covalent bond-forming reactive amine groups was not.

Tuning Nanopores in Tubular Ceramic Nanofiltration Membranes with Atmospheric-Pressure Atomic Layer Deposition: Prospects for Pressure-Based In-Line Monitoring of Pore Narrowing

Atomic layer deposition (ALD) is known for its unparalleled control over layer thickness and 3D conformality and could be the future technique of choice to tailor the pore size of ceramic nanofiltration membranes. However, a major challenge in tuning and functionalizing a multichannel ceramic membrane is posed by its large internal pore volume, which needs to be evacuated during ALD cycling. This may require significant energy and processing time. This study presents a new reactor design, operating at atmospheric pressure, that is able to deposit thin layers in the pores of ceramic membranes. In this design, the reactor wall is formed by the industrial tubular ceramic membrane itself, and carrier gas flows are employed to transport the precursor and co-reactant vapors to the reactive surface groups present on the membrane surface. The layer growth for atmospheric-pressure ALD in this case proceeds similarly to that for state-of-the-art vacuum-based ALD. Moreover, for membrane preparation, this new reactor design has three advantages: (i) monolayers are deposited only at the outer pore mouths rather than in the entire bulk of the porous membrane substrate, resulting in reduced flow resistances for liquid permeation; (ii) an in-line gas permeation method was developed to follow the layer growth in the pores during the deposition process, allowing more precise control over the finished membrane; and (iii) expensive vacuum components and cleanroom environment are eliminated. This opens up a new avenue for ceramic membrane development with nano-scale precision using ALD at atmospheric pressure.

Effects of high hydrostatic pressure treatment on the structural properties of interfacial protein of rabbit myosin emulsion

High hydrostatic pressure (HHP) treatment (< 200 MPa) has been known to increase the emulsification properties of myosin. However, the relationship between interfacial elasticity and emulsion stability is complicated. Therefore, this study was focused on exploring the effects of high hydrostatic pressure on the physiochemical and structural properties of interfacial proteins within a stabilized oil-in-water (O/W) rabbit myosin emulsion. We analyzed the adsorption rate and structure of interfacial proteins pressurized under 0.1 [control], 100, 150, and 200 MPa prior to emulsion preparation. As the pressure was increased from 0.1 to 150 MPa, the adsorption rate of interfacial protein increased. HHP treatment caused myosin to unfold, which enhanced the exposure of reactive sulfhydryl and hydrophobic groups. Furthermore, the frequency of hydrogen bonding and hydrophobic interactions increased. As hydrogen bonding increased, the secondary structure of myosin became more stable. As the pressure increased to 200 MPa, the interfacial myosin aggregated, displaying a decreased surface hydrophobicity and reactive sulfhydryl groups (P < 0.05) and thus the emulsion stability decreased. In conclusion, HHP treatment of myosin at 150 MPa significantly improved the stability of the myosin emulsion. Industrial relevanceMyosin is an important protein in meat and its emulsion stability can be enhanced by HHP. This study reveals the conformational mechanism by which HHP improves the stability of myosin emulsions, providing potential theoretical basis for the application of HHP treatment to improve the quality of emulsified meat products as a non-thermal processing technology in the practical production.

Effect of H2O vapor on plasma-assisted partial oxidation of CH4 over PtOx/BN nanoribbon aerogel catalysts

Ultralight BN nanoribbon aerogels confined highly dispersed PtOx nanoparticles (NPs) catalysts (PtOx/BN-na) were prepared and utilized for plasma-assisted partial oxidation of CH4 (POM) in a CH4−O2 flow system with H2O vapor cofeed at low temperature. The synergistic effect of H2O vapor and Pt2/BN-na catalyst overcomes a tradeoff problem between CH4 conversion and oxygenate selectivity, achieving 95% selectivity towards incomplete oxidation products at a 13% CH4 conversion. The total oxygenate productivity reached 106.5 mmoloxy gcat−1 h−1, which is one of the best results among the state-of-the-art catalysts for gas and liquid POM reaction. Based on experimental results of D and O18 isotope labelling, in situ OES, and in situ DRIFTS, the surface reactive hydroxyl groups or/and •OH radical, generated from the plasma-activated reaction of H2O + O2 on PtOx NPs active sites, are suggested as key factors to promote the POM reaction. The results of the Catalyst Surface Plasma-Assisted Oxidation Reaction (CSPOR) demonstrate that H2O not only promotes the selective oxidation of chemisorbed hydrocarbon species to oxygenate species, but also facilitates the desorption of oxygenates from the catalysts.

Mechanism of CO2 and H2O Action on Char in Oxy-fuel Combustion with Wet Flue Gas Recirculation

The mechanism of the combined action of the C–CO2 and C–H2O reactions has yet to be clarified in the study of oxy-fuel combustion with wet flue gas recirculation (WFGR). The ultrahigh temperature (1573 K) and atmosphere of an industrial boiler are simulated in the flat flame burner reaction system (FFB-RS). The measurement of surface reactive groups and combustion reactivity of char uses Fourier transform infrared spectroscopy (FTIR) and a microfluidized bed reaction analyzer (MFBRA). The results show that char combustion reactivity has an excellent positive correlation with an O-containing reactive group. Above a 35% H2O concentration, its physical properties dominate, while below 35%, its chemical properties play a significant role. When the ratio of H2O/CO2 is close to 1, there is a synergistic relationship between the C–CO2 and C–H2O reactions, which did not occupy the same active sites, promoting the formation of O-containing reactive groups (33.83%) and alkyl complexes (19.6%) with a combustion reaction rate of 0.225%/s.

Ultrasmall Superparamagnetic Iron Oxide Nanoparticles as Nanocarriers for Magnetic Resonance Imaging: Development and In Vivo Characterization.

Ultrasmall superparamagnetic iron oxide nanoparticles (uSPIOs) are attractive platforms for the development of smart contrast agents for magnetic resonance imaging (MRI). Oleic acid-capped uSPIOs are commercially available yet hydrophobic, hindering in vivo applications. A hydrophilic ligand with high affinity toward uSPIO surfaces can render uSPIOs water-soluble, biocompatible, and highly stable under physiological conditions. A small overall hydrodynamic diameter ensures optimal pharmacokinetics, tumor delivery profiles, and, of particular interest, enhanced T 1 MR contrasts. In this study, for the first time, we synthesized a ligand that not only fulfills the as-proposed properties but also provides multiple reactive groups for further modifications. The synthesis delivers a facile approach using commercially available reactants, with resultant uSPIO-ligand constructs assembled through a single-step ligand exchange process. Structural and molecular size analyses confirmed size uniformity and small hydrodynamic diameter of the constructs. On average, 43 reactive amine groups were present per uSPIO nanoparticle. Its r 1 relaxivity has been tested on a 7 Tesla MR instrument and is comparable to that of the clinically available T 1 gadolinium-based contrast agent GBCA (1 vs 3 mM-1 s-1, respectively). A significant decrease in tumor T1 (15%) within 1 h of injection and complete signal recovery after 2 h were detected with a dose of 7 μg Fe/g mouse. The agent also has high r 2 relaxivity and can be used for T 2 contrast-enhanced MRI. Taken together, good relaxation and delivery properties and the presence of multiple surface reactive groups can facilitate its application as a universal MRI-compatible nanocarrier platform.

Surface modified hexagonal upconversion nanoparticles for the development of competitive assay for biodetection.

Up-conversion nanoparticles (UCNPs) of sodium yttrium fluoride with ytterbium and erbium ions as sensitizer and activator (β-NaYF4/Yb3+/Er3+) have been synthesised by a solvothermal method. The synthesised particles were found to be highly uniform in size (~50nm) and of hexagonal crystal phase producing strong up-conversion luminescence dominated in the green wavelength region. During the synthesis, photoluminescence properties of the reaction mixture were monitored at regular intervals to ensure the required particle size distribution and luminescence efficiency. The hydrophobic particles thus obtained were modified by coating with silica, yielding particles that were stable in aqueous media. The silica coated UCNPs were further modified with maleimide-polyethylene glycol-silane (mal-PEG-silane) to provide thiol reactive surface groups. The silanized, maleimide-bearing UCNPs were effective for conjugating to reductively-cleaved half antibodies against ofloxacin, a veterinary antibiotic, to produce photoluminescent nanobiosensors for its detection and quantification. The speed and minimum detection concentration (~10nM) that we report for a competitive assay of ofloxacin in this study is promising for developing sensors for this and other biomolecules.

A Simplified and Robust Activation Procedure of Glass Surfaces for Printing Proteins and Subcellular Micropatterning Experiments.

Depositing biomolecule micropatterns on solid substrates via microcontact printing (µCP) usually requires complex chemical substrate modifications to initially create reactive surface groups. Here, we present a simplified activation procedure for untreated solid substrates based on a commercial polymer metal ion coating (AnteoBindTM Biosensor reagent) that allows for direct µCP and the strong attachment of proteins via avidity binding. In proof-of-concept experiments, we identified the optimum working concentrations of the surface coating, characterized the specificity of protein binding and demonstrated the suitability of this approach by subcellular micropatterning experiments in living cells. Altogether, this method represents a significant enhancement and simplification of existing µCP procedures and further increases the accessibility of protein micropatterning for cell biological research questions.

In Vivo Bioengineering of Beta Cells with Immune Checkpoint Ligand as a Treatment for Early-Onset Type 1 Diabetes Mellitus.

Type 1 diabetes mellitus (T1DM) is an autoimmune disease caused by autoreactive T cells targeting the insulin-producing beta (β) cells. Despite advances in insulin therapy, T1DM still leads to high morbidity and mortality in patients. A key focus of T1DM research has been to identify strategies that re-establish self-tolerance and suppress ongoing autoimmunity. Here, we describe a strategy that utilizes pretargeting and glycochemistry to bioengineer β cells in situ to induce β-cell-specific tolerance. We hypothesized that β-cell-targeted Ac4ManNAz-encapsulated nanoparticles deliver and establish β cells with high levels of surface reactive azide groups. We further theorized that administration of a dibenzylcyclooctyne (DBCO)-functionalized programmed death-ligand 1 immunoglobulin fusion protein (PD-L1-Ig) can be readily conjugated to the surface of native β cells. Using nonobese diabetic (NOD) mice, we demonstrated that our strategy effectively and selectively conjugates PD-L1 onto β cells through bioorthogonal stain-promoted azide-alkyne cycloaddition. We also showed that the in vivo functionalized β cells simultaneously present islet-specific antigen and PD-L1 to the engaged T cells, reversing early onset T1DM by reducing IFN-gamma expressing cytotoxic toxic T cells and inducing antigen-specific tolerance.

“Sticky” carbon coating enables high-area-capacity lithium storage of silicon-graphitic carbon hybrid

Pulverization and surface instability have been identified as the main impediments to the application of Si anodes in high-energy lithium-ion batteries (LIBs). In this study, a Si-graphitic carbon hybrid (SiG) is created via embedding Si nanoparticles in between expanding graphite interlayers, thus to be adopted as a model system to unravel structure-properties relations for LIBs applications. We explore the impact of artificial surface coating layers on the lithium cycling performance of SiG particles. In comparison with native SiG and carbon-coated SiG (CC-SiG), we find that the “sticky-carbon” coating, i.e., an epoxy-rich layer on top of the carbon coating, gave rise to superior cycle performance. In the “sticky carbon” coated SiG (SCC-SiG), the surface chemistry appears to have a pivotal role in both alleviating electrode disintegration and forming a favorable SEI rich in fluorine-polymers. These positive findings are examined in electrodes with mass loading ranging from 1.0 to 5.0 mg/cm2, achieving area capacities up to ∼5.0 mAh/cm2. A full cell adopting >6 mg/cm2 LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode and SCC-SiG delivers stable cycling performances. It is hence unraveled that the carbon coating layer with reactive surface groups on the top is an unrecognized key for wide range of Si-based anodes.

Insight into the effect of oxygen vacancies and OH groups on anatase TiO2 for CO oxidation: A combined FT-IR and density functional theory study

Anatase TiO2 plays an important role in catalytic reaction. The present work focused on surface structural and electric structural properties of the anatase TiO2 doped with some 3d transition metals (Mn, Fe and Co). Taking the CO oxidation as a probe reaction, attempts to explain the influence of oxygen vacancies and surface OH groups on the reaction mechanism by using FT-IR characterization and DFT calculation. It is found that doping can activate the surface lattice oxygen by introducing spin polarization, thereby increasing the oxygen vacancy to adsorb more chemisorbed oxygen. It is also found that OH groups increase the catalytic performance by forming bicarbonate which is eventually consumed. At low temperature, the CO oxidation reaction by surface reactive oxygen species and hydroxyl groups together. At high temperature, CO molecules are oxidized by surface reactive oxygen species with CO2 desorption step as the controlling step. Finally, the reaction mechanism was summarized as a Eley-Rideal mechanism.

Chitosan, Polyethylene Glycol and Polyvinyl Alcohol Modified MgFe2O4 Ferrite Magnetic Nanoparticles in Doxorubicin Delivery: A Comparative Study In Vitro

Cancer-based magnetic theranostics has gained significant interest in recent years and can contribute as an influential archetype in the effective treatment of cancer. Owing to their excellent biocompatibility, minute sizes and reactive functional surface groups, magnetic nanoparticles (MNPs) are being explored as potential drug delivery systems. In this study, MgFe2O4 ferrite MNPs were evaluated for their potential to augment the delivery of the anticancer drug doxorubicin (DOX). These MNPs were successfully synthesized by the glycol-thermal method and functionalized with the polymers; chitosan (CHI), polyvinyl alcohol (PVA) and polyethylene glycol (PEG), respectively, as confirmed by Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction (XRD) confirmed the formation of the single-phase cubic spinel structures while vibrating sample magnetometer (VSM) analysis confirmed the superparamagnetic properties of all MNPs. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) revealed small, compact structures with good colloidal stability. CHI-MNPs had the highest DOX encapsulation (84.28%), with the PVA-MNPs recording the lowest encapsulation efficiency (59.49%). The 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) cytotoxicity assays conducted in the human embryonic kidney (HEK293), colorectal adenocarcinoma (Caco-2), and breast adenocarcinoma (SKBR-3) cell lines showed that all the drug-free polymerized MNPs promoted cell survival, while the DOX loaded MNPs significantly reduced cell viability in a dose-dependent manner. The DOX-CHI-MNPs possessed superior anticancer activity (<40% cell viability), with approximately 85.86% of the drug released after 72 h in a pH-responsive manner. These MNPs have shown good potential in enhancing drug delivery, thus warranting further optimizations and investigations.

Optimizing the catalytic activity of flame‐spray‐pyrolyzed Pt/Fe2O3 catalyst toward CO oxidation: Effect of fluorination and reduction

AbstractComprehending the characteristics of nanocatalyst and the effect of pretreatment on its catalytic performance is of great importance in the field of catalysis. The present study probes the catalytic performance of fluorinated Pt/Fe2O3 prepared by one step flame spray pyrolysis and the effect of pretreatment in CO oxidation. The characterization reveals that in‐situ fluorination of Pt/Fe2O3 in high temperature flame process contributed to low temperature reducibility, improved dispersion abundant surface oxygen vacancies and reactive hydroxyl groups. It is noteworthy that the optimal catalytic performance was attained after reduction of fluorinated Pt/Fe2O3 in 10% H2 at 200 °C (F‐Pt/Fe‐200). The abundant surface hydroxyl group and oxygen vacancies facilitated faster reaction. The in‐situ DRIFTS reveals the consumption of hydroxyl group in F‐Pt/Fe‐200 which contributed to the amelioration of CO oxidation. Aside the better stability of F‐Pt/Fe‐200, complete conversion of 2% and 4% CO was achieved at 150 °C and 200 °C, respectively, indicating the feasible utilization of flame‐made fluorinated Pt/Fe2O3. Conclusively, the fluorine formed a strong bond with Pt, which ameliorated oxidative and thermal stability.

Silver Nanoparticles (AgNPs) Biosynthesized by Aspergillus flavus KF946095; their Characterization and Antibacterial Activity

The antimicrobial agents of silver nanoparticles (AgNPs) have been applied a little while back in diverse therapeutic studies. In this analysis, AgNPs were biosynthesized using an ecologically welcomed and cost-effective simple of bio-reduction. An isolate of Aspergillus flavus KF946095 (A. flavus) was found to biosynthesize AgNPs; the size of AgNPs was (56nm) and detected by UV-Vis analysis at (400 nm). The reducing properties for biosynthesis of AgNPs are mainly due to the protein functional surface reactive groups detected by Fourier Transform Infrared spectroscopy (FTIR).Whereas, FTIR for AgNPs showed different peaks at 3994.5, 3201.6, 1801.4, 1643.2 and 1604.7 cm-1 that shared with the biosynthesize and stability of AgNPs as protein capping agents. Transmission Electron Microscope (TEM) confirmed the scattering of biosynthesized AgNPs within a sol with oval and round shapes. The antibiotic susceptibility test was studied for some pathogenic bacteria. Staphylococcus aureus DSM 1104 (S. aureus) appeared to be the more resistant strain; it resisted the action of 6 antibiotics out of 8 ones tested. MIC value of AgNPs was 20µg/mL and antibiotic ciprofloxacin was 30µg/mL. Mixture of MIC values or double MIC values distinctively inhibited the multidrug resistant (MDR) S.aureus.

Parallel Multiparameter Study of PEI-Functionalized Gold Nanoparticle Synthesis for Biomedical Applications: Part 2. Elucidating the Role of Surface Chemistry and Polymer Structure in Performance.

Elucidating the polyethyleneimine (PEI) chemistry to predictively and reproducibly synthesize gold nanoparticle (AuNP)-PEI conjugates with desired properties has been elusive despite evaluation in numerous studies and reported enhanced properties. The lack of reproducible methods to control the core size and stability has led to contradictory results for performance and safety; thus, advancement of the conjugate platform for commercial use has likely been hindered. Recently, we reported a robust, reproducible method for synthesizing PEI-functionalized AuNPs (Au-PEIs), providing an opportunity to investigate structure-function relationships and to further investigate synthesis parameters affecting performance, where only materials stable in biological media are candidates for use. The properties of Au-PEIs prepared by the optimized reduction of HAuCl4 using four different structural variants of PEI changed significantly with the PEI molar mass and backbone form (branched or linear). In the present study using our previously reported synthesis procedure, comprehensive analysis of properties such as size distribution, surface plasmon resonance (SPR), morphological state, surface functionality, and the shelf life has been systematically evaluated to elucidate the role of surface chemistry and reactive groups involved in conjugation, as a function of conjugate size and morphology. Being important for commercial adoption, the chemistry was related to the observed colloidal stability of the product in relevant media, including exposure to physiological variables such as salt, pH, proteins, and thermal changes. Overall, this work advances progress toward smart design of engineered nanoscale drug delivery systems and devices by providing unreported details of contributions affecting formation, stability, and fate.

Mapping the Surface Groups of Amine-Rich Carbon Dots Enables Covalent Catalysis in Aqueous Media

Summary Carbon nanodots stand as the missing link between the molecular and the nanoscale world, owing to the unique molecular-like behavior emerging from their synthetic precursors. A converging set of analytical and spectroscopic data yields a precise inventory of the surface reactive groups of amine-rich carbon dots (NCDs-1). As a result, NCDs-1 provide a multi-functional nano-platform that is able to covalently activate carbonyl groups, form iminium-ions and enamine intermediates, and efficiently promote diverse aminocatalytic transformations in water. Remarkably, the catalytic activity of carbon dots can also govern the stereoselectivity in the bond-forming event. Indeed, the use of chiral carbon dots (NCDs-7) as catalysts affords the final aldol products with significant enantiomeric excess. The successful implementation of carbon nanostructures into chemical roles so far restricted to molecular systems opens new avenues for advanced applications where the nanoscale and the molecular realms will merge and complement each other.

Antibody-Enabled Antimicrobial Nanocapsules for Selective Elimination of Staphylococcus aureus.

Targeted bactericide nanosystems hold significant promise to improve the efficacy of existing antimicrobials for treatment of severe bacterial infections, minimizing the side effects and lowering the risk of the development of antibiotic resistance. In this work, we developed antibody-functionalized nanocapsules (NCs) containing antibacterial essential oil (EO) for selective and effective eradication of Staphylococcus aureus. Antibacterial EO NCs were produced via self-assembly nanoencapsulation in the plant-derived protein zein. The obtained EO NCs were decorated with aminocellulose to provide more reactive surface groups for carboxyl-to-amine immobilization of a antibody that is specific against S. aureus. The antibody-enabled EO NCs (Ab@EO NCs) demonstrated 2-fold higher bactericidal efficacy against the targeted bacterium compared to the pristine EO NCs at the same concentrations. The improved antibacterial effect of the Ab@EO NCs toward S. aureus was also confirmed in a real-time assay by monitoring bacterial cells elimination using a quartz crystal microbalance. Furthermore, the Ab@EO NCs selectively decreased the load and changed the cell morphology of the targeted S. aureus in a mixed inoculum with nontargeted Pseudomonas aeruginosa. Applying the nanoformulated antibacterial actives to an in vitro coculture model of the bacteria and skin fibroblasts resulted in suppression of S. aureus growth while preserving the human cells viability. The novel antibody-enabled antibacterial NCs showed potential for improving the treatment efficacy of staphylococcal infections, minimally affecting the beneficial microbial and human cells.

In situ functionalization of HPLC monolithic columns based on divinylbenzene-styrene-4-vinylbenzyl chloride

The properties of chromatographic columns are largely determined by functional groups located on the sorbent surface. For monolithic columns, surface functional groups can be created during synthesis stage or by chemical bonding with the complete surface of the sorbent. One of sorbent modification approach is to use on-column click reactions with surface reactive groups. In this study, the surface treatment of monolithic sorbent based on divinylbenzene (DVB), styrene (St) and 4-vinylbenzyl chloride (4VBC) copolymer by heterocyclic nitrogen-containing compounds 1-methylimidazole (1MI), 2-methylimidazole (2MI), 2-methylpyridine (2 MP) and 4-methylpyridine (4 MP) is described. The reaction of nitrogen-containing heterocycles with chloromethyl fragments on the surface results in formation of ion pairs and significantly changes the selectivity of monolithic columns. The chromatographic properties of prepared columns are studied. Modified columns can be operated in reversed-phase (RP) chromatography or in hydrophilic interaction liquid chromatography (HILIC) with different composition of the mobile phase. Separation examples of various chemical substances classes are given.