PMMA Nanoparticles Research Articles

Proline-Functionalized Magnetic Nanoparticles as Highly Performing Asymmetric Catalysts.

Amino acids have a crucial role in the field of asymmetric organocatalysis for the production of chiral compounds with high added value and specific biological activity. In particular, proline offers high activity and stereoselectivity for catalyzing aldol reactions in organic solvents. However, proline-based catalysts often lack water-solubility, accessibility, catalytic performance, or recovery in aqueous media. This work reports the design of proline-functionalized poly(methyl methacrylate) (PMMA) nanoparticles with a magnetic core that offer high availability of chiral units in water and high recyclability. A proline-based copolymerizable surfactant is designed and integrated onto the surface of PMMA nanoparticles through a miniemulsion polymerization process without using additional surfactants. The miniemulsion technique allows the incorporation of magnetite to the system to create a magnetically separable catalyst. The chiral nanocatalyst presents a high diastereoselective catalytic activity for the intermolecular aldol reaction between p-nitrobenzaldehyde and cyclohexanone in water.

Encapsulation of organic ultraviolet photoprotective actives into poly(methyl methacrylate) nanoparticles for sunscreen formulations

AbstractSkin cancer is the most common of all cancers worldwide. This way, it is mandatory to adopt an adequate sun protection routine, including sunscreen lotions. However, despite the proven effectiveness of numerous chemical filters, many of them are also known for their allergenic and carcinogenic potential effects, which can be mitigated by exploring some encapsulation routes. Thus, the present work evaluates the influence of seven distinct ultraviolet (UV) organic filters on the final particle size and molecular weight distributions of poly(methyl methacrylate) (PMMA) beads. Moreover, the sun protection factors (SPF) of the loaded nanoparticles are also evaluated when used for preparation of sunscreen formulations. The UV filters did not affect the course of MMA miniemulsion polymerizations significantly, enabling the synthesis of loaded nanoparticles. Nevertheless, adding the filters shifted the particle size distributions toward larger diameters, which are appropriate for cosmetic formulations. Based on the SPF analyses, it was also possible to observe a 12‐fold increase in the SPF values of the prepared formulations and an increase in the critical wavelength. Therefore, the in situ incorporation of distinct UV filters during miniemulsion MMA polymerizations constitutes a robust and versatile technology to produce PMMA nanoparticles loaded with UV filters for preparation of sunscreen formulations.

Overcoming Resistance of Caco-2 Cells to 5-Fluorouracil through Diruthenium Complex Encapsulation in PMMA Nanoparticles.

Drug resistance, one of the main drawbacks in cancer chemotherapy, can be tackled by employing a combination of drugs that target different biological processes in the cell, enhancing the therapeutic efficacy. Herein, we report the synthesis and characterization of a new paddlewheel diruthenium complex that includes 5-fluorouracil (5-FU), a commonly used anticancer drug. This drug was functionalized with a carboxylate group to take advantage of the previously demonstrated release capacity of carboxylate ligands from the diruthenium core. The resulting hydrophobic complex, [Ru2Cl(DPhF)3(5-FUA)] (Ru-5-FUA) (DPhF = N,N'-diphenylformamidinate; 5-FUA = 5-fluorouracil-1-acetate) was subsequently entrapped in poly(methyl methacrylate) (PMMA) nanoparticles (PMMA@Ru-5-FUA) via a reprecipitation method to be transported in biological media. The optimized encapsulation procedure yielded particles with an average size of 81.2 nm, a PDI of 0.11, and a zeta potential of 29.2 mV. The cytotoxicity of the particles was tested in vitro using the human colon carcinoma cell line Caco-2. The IC50 (half maximal inhibitory concentration) of PMMA@Ru-5-FUA (6.08 μM) was just slightly lower than that found for the drug 5-FU (7.64 μM). Most importantly, while cells seemed to have developed drug resistance against 5-FU, PMMA@Ru-5-FUA showed an almost complete lethality at ∼30 μM. Conversely, an analogous diruthenium complex devoid of the 5-FU moiety, [Ru2Cl(DPhF)3(O2CCH3)] (PMMA@RuA), displayed a reduced cytotoxicity at equivalent concentrations. These findings highlight the effect of combining the anticancer properties of 5-FU with those of diruthenium species. This suggests that the distinct modes of action of the two chemical species are crucial for overcoming drug resistance.

Structural and Optical Properties of PMMA-MgO Nanocomposite Film

This study investigates the structural, morphological, and optical properties of poly(methyl methacrylate) (PMMA) films incorporated with magnesium oxide (MgO) nanoparticles. The PMMA-MgO polymer nanocomposite (PNC) films were fabricated via solution casting method using varying weight percentages (1-4 wt%) of MgO nanoparticles. X-ray diffraction analysis confirmed the integration of MgO nanofillers in the PMMA matrix. Fourier transform infrared spectroscopy revealed interactions between PMMA and MgO nanoparticles. Atomic force microscopy demonstrated increased surface roughness in PNC films with higher MgO loading. Optical characterization using UV-visible spectroscopy showed enhanced absorption in the UV region and a noticeable peak at 280 nm due to MgO nanoparticles. The refractive index of PMMA-MgO PNCs increased with rising MgO content while the optical bandgap marginally decreased. The study highlights the potential of PMMA-MgO PNC films for advanced optoelectronic applications requiring high optical transparency and tuneable refractive index.

Development of acidochromic colloidal polymer nanoparticles containing azobenzene derivatives as eco-friendly time-dependent anticounterfeiting inks

N,N-dihydroxyethyl azobenzene compounds with different functional groups of hydrogen, electron-donating hydroxyl (OH), and electron-withdrawing nitro (NO2) were synthesized by a two-step diazotization and coupling method. Colloidal poly(methyl methacrylate) (PMMA) nanoparticles, prepared by emulsifier-free emulsion polymerization, were doped with 3 wt% of the three azobenzenes to prepare acidochromic colloids. Acidochromic properties of all the azobenzenes and the polymer colloids were investigated in acidic buffers. Azobenzene compounds doped on polymer particles showed different colors in buffers with different pH values due to the presence of different functional groups, which makes them highly applicable as acid detectors. The electron-withdrawing NO2 functional group caused a small bathochromic shift in the azobenzene spectrum, and the azobenzene containing OH functional group showed higher bathochromic shift than the unsubstituted azobenzene. The colloidal PMMA nanoparticles doped with the three azobenzene compounds were used as eco-friendly inks for stamping and hand-signing on cellulosic papers. Exposure to acidic HCl vapor resulted in different coloration of the printed marks due to the protonation of the azobenzenes. These colors of the protonated forms were decayed with time and also after exposure to triethylamine vapor. The stamped patterns showed a high fatigue and no change in color intensity up to 20 cycles. This shows that these polymeric inks can be used as anticounterfeiting inks for security-marking of confidential documents and banknotes. The developed inks showed time-dependent characteristics and responsivity to acid and base vapors, which make them highly applicable in security marking of confidential documents and also detection of acid and base.

Colloidal Polymer Nanoparticles as Smart Inks for Authentication and Indication of Latent Fingerprints and Scratch.

An environmentally friendly smart ink was developed by incorporating fluorescein into functionalized poly(methyl methacrylate) (PMMA) nanoparticles synthesized using an emulsifier-free emulsion copolymerization approach. The functional comonomers of 2-(dimethylamino)ethyl methacrylate (DMAEMA), acrylamide, hydroxyethyl methacrylate, and glycidyl methacrylate in 10 wt % with respect to methyl methacrylate were used to obtain the functionalized colloidal PMMA nanoparticles. Functional groups of the latex nanoparticles were characterized by Fourier-transform infrared spectroscopy. Field emission scanning electron microscopy results showed that all of the latex nanoparticles have nearly spherical morphologies with variations in size and surface smoothness due to the presence of different comonomers. Ultraviolet-visible and fluorescence spectra indicated that the fluorescein-doped latex nanoparticles containing the DMAEMA comonomer had the highest absorbance and fluorescence intensity. In the alkaline media, fluorescein turns to a dianion, showing a red shift and increased absorbance in the UV-vis spectroscopy. In addition, the electron inductive characteristics of the tertiary amine groups result in enhancing the conjugation of fluorescein molecules and increasing the fluorescence intensities. Therefore, the colloidal nanoparticles with amine functional groups were used in the formulation of a smart ink with applications in securing documents and fingerprints, encrypting banknotes and money, detecting latent fingerprints, crafting anticounterfeiting paper, and eventually providing optical detection and indication of surface scratches.

Paclitaxel release from hollow PMMA nanoparticles: Factors affecting release rate as quantified via dialysis and membrane centrifugation

Despite known limitations, dialysis and centrifugation remain standard methods for quantifying in vitro drug release kinetics. In the context of quantifying drug release from nanoparticles, dialysis uses a membrane to retain nanoparticles whilst drug released from the nanoparticles transfers across the membrane. The present work investigates the use of dialysis and solely for comparison membrane centrifugation for quantitative characterisation of Paclitaxel (PAX) release from hollow poly(methyl methacrylate) (PMMA) nanoparticles (PAX-NPs) synthesised using a simple one-pot miniemulsion polymerisation system. The impact on drug release rate when using GSH to cleave disulphide crosslinked PMMA, the incorporation of methacrylic acid as a co-monomer, and use of a hydrotrope (sodium subsalicylate) for enhanced drug solubility are discussed. Finally, we summarise the limitations of dialysis and membrane centrifugation due to a complex interplay of factors including drug concentration, molecular weight, hydrophobicity, internal to external dialysis volume and partitioning.

Comparative Study of Polymer-Grafted BaTiO3 Nanoparticles Synthesized Using Normal ATRP as Well as ATRP and ARGET-ATRP with Sacrificial Initiator with a Focus on Controlling the Polymer Graft Density and Molecular Weight.

Structurally well-defined polymer-grafted nanoparticle hybrids are highly sought after for a variety of applications, such as antifouling, mechanical reinforcement, separations, and sensing. Herein, we report the synthesis of poly(methyl methacrylate) grafted- and poly(styrene) grafted-BaTiO3 nanoparticles using activator regeneration via electron transfer (ARGET ATRP) with a sacrificial initiator, atom transfer radical polymerization (normal ATRP), and ATRP with sacrificial initiator, to understand the role of the polymerization procedure in influencing the structure of nanoparticle hybrids. Irrespective of the polymerization procedure adopted for the synthesis of nanoparticle hybrids, we noticed PS grafted on the nanoparticles showed moderation in molecular weight and graft density (ranging from 30,400 to 83,900 g/mol and 0.122 to 0.067 chain/nm2) compared to PMMA-grafted nanoparticles (ranging from 44,620 to 230,000 g/mol and 0.071 to 0.015 chain/nm2). Reducing the polymerization time during ATRP has a significant impact on the molecular weight of polymer brushes grafted on the nanoparticles. PMMA-grafted nanoparticles synthesized using ATRP had lower graft density and considerably higher molecular weight compared to PS-grafted nanoparticles. However, the addition of a sacrificial initiator during ATRP resulted in moderation of the molecular weight and graft density of PMMA-grafted nanoparticles. The use of a sacrificial initiator along with ARGET offered the best control in achieving lower molecular weight and narrow dispersity for both PS (37,870 g/mol and PDI of 1.259) and PMMA (44,620 g/mol and PDI of 1.263) nanoparticle hybrid systems.

Synthesis of Ultrahigh Molecular Weight Poly(methyl Methacrylate) via the Polymerization of MMA Initiated by the Combination of Palladium Carboxylates with Thiols.

A novel synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) using organosulfur compounds combined with a catalytical amount of transition metal carboxylates as an initiator has been developed. The combination of 1-octanethiol with palladium trifluoroacetate (Pd(CF3COO)2) was found to be a very efficient initiator for the polymerization of methyl methacrylate (MMA). An ultrahigh molecular weight PMMA with a number-average molecular weight of 1.68 × 106 Da and a weight-average molecular weight of 5.38 × 106 Da has been synthesized at the optimal formulation of [MMA]:[Pd(CF3COO)2]:[1-octanethiol] = 94,300:8:23 at 70 °C. A kinetic study showed that the reaction orders with respect to Pd(CF3COO)2, 1-octanethiol, and MMA are 0.64, 1.26, and 1.46, respectively. A variety of techniques such as proton nuclear magnetic resonance spectroscopy (1H NMR), electrospray ionization mass spectroscopy (ESI-MS), size exclusion chromatography (SEC), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and electron paramagnetic resonance spectroscopy (EPR) were employed to characterize the produced PMMA and palladium nanoparticles (Pd NPs). The results revealed that Pd(CF3COO)2 was firstly reduced by the excess of 1-octanethiol to form Pd NPs at the early stage of the polymerization, followed by the adsorption of 1-octanethiol on the surface of nanoparticles and subsequent generation of corresponding thiyl radicals to initiate the polymerization of MMA.

Synthesis of ferrofluid DAA-Glu COF@Aminated alginate/Psyllium hydrogel nanocomposite for effective removal of polymethyl methacrylate nanoparticles and silver quantum dots pollutants

BackgroundPolymethyl methacrylate (PMMA) is widely used in biomedical applications. It exhibits slow degradation rates and thus is categorized as a potential hazardous pollutant. Similarly, silver quantum dots (Ag-QDs) have been recently listed as common pollutants based on their recent industrial applications. The aim is to design a novel nanocomposite via the combination of ferrofluids, covalent organic frameworks and Aminated alginate/Psyllium hydrogel as effective multifunctional nanocomposite for removal of PMMA nanoparticles (NPs) and Ag-QDs from water. MethodsDeveloped nanocomposite was fully identified from FTIR studies, electron microscopy, XRD and XPS. The removal process was optimized via detailed optimization of several parameters such as pH, shaking time (kinetic studies), nanocomposite dosage, pollutant concentration, temperature (thermodynamic studies) and ionic strength. Finally, the produced hybrid Ag-QDs@nanosorbent was examined as sustainable nanocatalyst for reducing Nitroxynil drug (NIX), a common hazardous pollutant Significant Findings98.02% and 96.36% removal efficiencies were achieved for PMMA NPs and Ag-QDs, respectively through process optimization.Kinetic studies revealed a complex heterogeneous chemisorption process that was interpreted by several kinetic models. Process spontaneity was confirmed from the thermodynamic studies. Process applicability in real water treatment of spiked samples with PMMA NPs and Ag-QDs as the target pollutants was accomplished. Finally, Ag-QDs@nanosorbent showed promising results as nanocatalyst for the pseudo-first order reduction of NIX with k=1.319 min−1.

In vitro toxicity of naringin and berberine alone, and encapsulated within PMMA nanoparticles

Phytochemical compounds, such as naringin and berberine, have been used for many years due to their antioxidant activities, and consequently, beneficial health effects. In this study, it was aimed to evaluate the antioxidant properties of naringin, berberine and poly(methylmethacrylate) (PMMA) nanoparticles (NPs) encapsulated with naringin or berberine and their possible cytotoxic, genotoxic, and apoptotic effects on mouse fibroblast (NIH/3 T3) and colon cancer (Caco-2) cells. According to the results of the study, it was found that the 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition antioxidant activity of naringin, berberine, and naringin or berberine encapsulated PMMA NPs, was significantly increased at higher tested concentrations due to the antioxidant effects of naringin, berberine and naringin or berberine encapsulated PMMA NPs. As a result of the cytotoxicity assay, after 24-, 48- and 72-h of exposure, all of the studied compounds caused cytotoxic effects in both cell lines. Genotoxic effects of studied compounds were not registered at lower tested concentrations. Based on these data, polymeric nanoparticles encapsulated with naringin or berberine may contribute to new treatment approaches for cancer, but further in vivo and in vitro research is required.

Influence of Eu3+ dopant on the third order nonlinear optical properties of PbO/PMMA nanocomposites

ABSTRACT PbO/PMMA, 3 and 6 mol% ion-doped PbO/PMMA nanocomposites were synthesised using an easy chemical precipitation method. For all of the nanocomposites, the XRD pattern confirms the orthorhombic structure of PbO. The morphology of PbO nanoparticles in PMMA is revealed by the SEM graph. The formation of nanocomposites containing Eu3+ doped PbO nanoparticles in PMMA is confirmed by FTIR. When Eu3+ doped PbO nanoparticles in PMMA are compared to bulk PbO, UV–Vis optical absorption findings demonstrate a blue shift on the absorption band. The optical band gap energy decreases with increasing Eu3+ dopant concentration and is related to red-shifted phenomena. The PL spectra reveal an emission peak associated with blue emission caused by a synthesis defect. For 6 mol% Eu3+ ion doped PbO/PMMA nanocomposites, third-order nonlinear optical parameters such as nonlinear optical susceptibility (χ(3)), nonlinear optical refractive index (n2), and nonlinear optical absorption coefficient (β) are determined by Z-scan technique, and the values are found to be 4.468 × 10−6 esu, 1.257 × 10−7cm2/W, and 9.837 × 10−3 cm/W, respectively. The strong nonlinearity in the current Eu3+ ion-doped PbO/PMMA nanocomposites empowers its promising applications in third-order nonlinear optical devices.

Plasmon-enhanced luminescence of rare-earth ions by gold and silver nanoparticles in PMMA

In this work plasmon resonances in gold and silver nanoparticles to enhance luminescent properties of PMMA doped with different rare-earth ions densities are investigated. For this purpose, a rate equation model based on the Förster theory is used. This model describes the luminescent dynamics between donor and acceptor rare earth ions and considers the electric field changes due to metallic nanoparticles. The MNPBEM Matlab toolbox is used to calculate the electric field in our system, including the electric field of the excitation and the electric field induced by the nanoparticle. The results show that rare earth luminescence can be increased in the proximity of spherical gold and silver nanoparticles due to the change in the optical field and the transition rates. Accordingly, the rate equation model proposed here explains the increase in luminescent emission when the dopants interact with the metal nanoparticles. Additionally, the calculations allow to find the optimal conditions of nanoparticle size and excitation wavelength to achieve the maximum amplification of optical field and, therefore, the maximum amplification of the emission of rare earth ions.

A systematic study of a polymer-assisted carboxylate-based MOF synthesis: multiple roles of core cross-linked PMAA-b-PMMA nanoparticles

Colloidaly stable carboxylate-based metal organic frameworks (MOFs), grown from acid decorated nanoparticles synthesized via PISA.

Synthesis of PMMA Nanoparticles Loaded with Geopropolis Extract from the Brazilian Stingless Bee Melipona quadrifasciata Lepeletier, 1836 by Miniemulsion Polymerization

AbstractThe present work aims to encapsulate the concentrated geopropolis extract from the Brazilian stingless bee Melipona quadrifasciata quadrifasciata Lepeletier, 1836 in poly(methyl methacrylate) (PMMA) nanoparticles produced by miniemulsion polymerization. The concentrated geopropolis extract is obtained by hydroalcoholic maceration and characterized by ultraviolet–visible spectrophotometry (UV–Vis) to quantify flavonoids and polyphenols in terms of quercetin (Q) and galic acid (GA), respectively. The PMMA‐Propolis nanoparticles is characterized by size exclusion chromatography (SEC), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), UV–Vis and nuclear magnetic resonance (NMR1H). UV–Vis results of the geopropolis extract revealed an average flavonoid content of 22.51 mg Q g–1 and an average polyphenol content of 10.15 mg GA g–1. TEM images showed that the produced PMMA nanoparticles are spherical, and their average diameter reduced from 72.62 to 44.60 nm by increasing the propolis concentration from 0% to 40%. Additionally, the kinetic data reveal a reduction of the polymerization reaction rate as well as the average molecular weight when raising the propolis extract concentration in the reaction media. These results suggest that propolis extract may be used as a biocompatible and biodegradable co‐stabilizer and chain transfer agent in miniemulsion polymerization reactions of vinyl monomers.

Trithiocarbonate-Mediated RAFT Polymerization Enables the Synthesis of Homotelechelic N-Vinylpyrrolidone Oligomers with Surfactant Properties

Poly(N-vinylpyrrolidone) (PVP) is a well-known biocompatible polymer widely used in cosmetics, pharmaceuticals, and many other applications and is usually synthesized via radical polymerization. High molar mass PVP lacks biodegradability according to the OECD 301 F standard and can lead to permanent accumulation within the body or in the environment. Nowadays, lower molar mass PVP is produced via xanthate-mediated reversible addition–fragmentation chain-transfer (RAFT) polymerization. However, this type of polymerization also leads to a large amount of undesired dimer formation. Herein, various homotelechelic PVP oligomers were prepared via a trithiocarbonate-mediated RAFT polymerization with the production of a minimal amount of unsaturated dimer. These PVP oligomers showed similar surfactant properties as the well-known Lutensol AT50 surfactant, and they were used as a nonionic surfactant in a typical radical aqueous miniemulsion polymerization of methyl methacrylate (MMA) to produce well-defined PMMA nanoparticles. Additionally, PVP oligomers showed no toxicity to the bacterial strain Escherichia coli and to the water fleas Daphnia pulex, which is promising for safe release in wastewater systems.

Structural Characterization, Thermal Stability and Non-Isothermal Kinetic Analysis of Decomposition of Poly(methylmethacrylate) and Titanium Dioxide Nanocomposites

In this study poly(methylmethacrylate) (PMMA) and the corresponding nanocomposites loaded with titanium dioxide (TiO2) films were prepared by a solution casting method. All materials were characterized by Fourier transform infrared spectroscopy, UV-visible spectroscopy, X-ray diffraction and scanning electron microscopy. The thermal properties were investigated by differential scanning calorimetry and thermogravimetric analysis. The results showed that the incorporation of TiO2 nanoparticles in PMMA decreased the thermal stability of the polymer. Moreover, the kinetic study of the thermal degradation showed that the apparent activation energies of the nanocomposites PMMA/TiO2 were lower compared to the pure PMMA, confirming the catalytic effect of TiO2 nanoparticles on the PMMA thermal decomposition. Furthermore, g(α), which is the integral form of the reaction mechanism function, showed that the degradation mechanism of the PMMA nanocomposites was strongly dependent on the TiO2 amount introduced into their matrices. Finally, the degradation mechanism of the pure PMMA obeyed the R3 model corresponding to a phase boundary reaction (n = 3), whereas in the case of the PMMA/TiO2 nanocomposites, they obeyed the R2 model, corresponding to a phase boundary reaction (n = 2), for PMMA/TiO2 (3%) and an A1.5 model, corresponding to an Avrami-Erofeev correlation (m = 1.5), was obtained for the remaining nanocomposites PMMA/TiO2 (5, 7 and 10%).

Development of Cyanine 813@Imidazole-Based Doped Supported Devices for Divalent Metal Ions Detection

A NIR cyanine@imidazole derivative Cy1 was synthesized and evaluated as a metal ion sensor in solution. Cy1 was shown to be very sensitive to all metal ions tested, presenting a blue shift in the absorption from 668 nm to 633 nm, followed by a change in colour from pale green to blue with Zn2+, Cd2+, Co2+, Ni2+ and Hg2+ ions. Despite the blue shift in the absorption, a decrease at 633 nm (with a colour change from pale green to colourless), as well as a quenching in the emission intensity at 785 nm were observed for Cu2+ ions. The results show the formation of sandwich complexes of two ligands per metal ion with the highest association constant observed for Cu2+ (Log Kass.abs = 14.76 ± 0.09; Log Kass.emis. = 14.79 ± 0.06). The minimal detectable amounts were found to be 31 nM and 37 nM, with a naked eye detection of 2.9 ppm and 2.1 ppm for Hg2+ and Cu2+ ions, respectively. These results prompted us to explore the applicability of Cy1 by its combination with nanomaterials. Thus, Cy1@ doped MNs and Cy1@ doped PMMA nanoparticles were synthesized. Both nanosystems were shown to be very sensitive to Cu2+ ions in water, allowing a naked-eye detection of at least 1 ppm for Cy1@ doped MNs and 7 ppm for Cy1@ doped PMMA. This colourimetric response is an easy and inexpensive way to assess the presence of metals in aqueous media with no need for further instrumentation.

Bovine Serum Albumin Conjugation in Superparamagnetic/Poly(methyl methacrylate) Nanoparticles as an Alternative for Magnetic Enzyme-Linked Immunosorbent Assays.

Nanomaterials, such as magnetic nanoparticles have attracted significant attention of medical area due to their capacity to improve the performance of immunoassays. Therefore the aim of this work was to study the bovine serum albumin (BSA) conjugation in superparamagnetic (MNPs)/poly(methyl methacrylate) (PMMA) nanoparticles with further characterization and application in enzyme-linked immunosorbent (ELISA) assay. The successful conjugation of BSA in MNPs- PMMA nanoparticles was confirmed by several techniques, including light scattering, zeta potential, transmission electron microscopy (TEM) and Lowry protein quantification assay. The superparamagnetic properties were confirmed by vibrating sample magnetometer. BSA conjugated MNPs-PMMA nanoparticles presented higher interactions with antibody than free BSA. The BSA + MNPs-PMMA nanoparticles (magnetic ELISA assay) reduced the time and increased the sensibility of traditional ELISA assay, reinforcing the idea that the use these nanomaterials are an excellent alternative for the immunoassays field.

Antibacterial, Antiviral, and Self-Cleaning Mats with Sensing Capabilities Based on Electrospun Nanofibers Decorated with ZnO Nanorods and Ag Nanoparticles for Protective Clothing Applications.

The COVID-19 pandemic has clearly shown the importance of developments in fabrication of advanced protective equipment. This study investigates the potential of using multifunctional electrospun poly(methyl methacrylate) (PMMA) nanofibers decorated with ZnO nanorods and Ag nanoparticles (PMMA/ZnO-Ag NFs) in protective mats. Herein, the PMMA/ZnO-Ag NFs with an average diameter of 450 nm were simply prepared on a nonwoven fabric by directly electrospinning from solutions containing PMMA, ZnO nanorods, and Ag nanoparticles. The novel material showed high performance with four functionalities (i) antibacterial agent for killing of Gram-negative and Gram-positive bacteria, (ii) antiviral agent for inhibition of corona and influenza viruses, (iii) photocatalyst for degradation of organic pollutants, enabling a self-cleaning protective mat, and (iv) reusable surface-enhanced Raman scattering substrate for quantitative analysis of trace pollutants on the nanofiber. This multi-functional material has high potential for use in protective clothing applications by providing passive and active protection pathways together with sensing capabilities.