One-pot Co-precipitation Method Research Articles

A Minimalist Iron Oxide Nanoprobe for the High-Resolution Depiction of Stroke by Susceptibility-Weighted Imaging.

The precise mapping of collateral circulation and ischemic penumbra is crucial for diagnosing and treating acute ischemic stroke (AIS). Unfortunately, there exists a significant shortage of high-sensitivity and high-resolution in vivo imaging techniques to fulfill this requirement. Herein, a contrast enhanced susceptibility-weighted imaging (CE-SWI) using the minimalist dextran-modified Fe3O4 nanoparticles (Fe3O4@Dextran NPs) are introduced for the highly sensitive and high-resolution AIS depiction under 9.4 T for the first time. The Fe3O4@Dextran NPs are synthesized via a simple one-pot coprecipitation method using commercial reagents under room temperature. It shows merits of small size (hydrodynamic size 25.8nm), good solubility, high transverse relaxivity (r2) of 51.3 mM-1s-1 at 9.4 T, and superior biocompatibility. The Fe3O4@Dextran NPs-enhanced SWI can highlight the cerebral vessels readily with significantly improved contrast and ultrahigh resolution of 0.1mm under 9.4 T MR scanner, enabling the clear spatial identification of collateral circulation in the middle cerebral artery occlusion (MCAO) rat model. Furthermore, Fe3O4@Dextran NPs-enhanced SWI facilitates the precise depiction of ischemia core, collaterals, and ischemic penumbra post AIS through matching analysis with other multimodal MR sequences. The proposed Fe3O4@Dextran NPs-enhanced SWI offers a high-sensitivity and high-resolution imaging tool for individualized characterization and personally precise theranostics of stroke patients.

The Application of Tannic Acid-Coated Magnetite Nanoparticles for Recovery of Microplastics from the Water System

The presence of microplastics (MPs) is rapidly increasing in the environment, posing a significant threat to public health and the ecosystem. To monitor the impact of MPs, it is crucial to have standardized detection methods and MPs remediation techniques. Therefore, this study aimed to use tannic acid-coated magnetite nanoparticles to recover MPs, specifically polystyrene (PS) and polyethylene terephthalate (PET), from water bodies. A facile method for MPs recovery was established using the synthesized tannic acid-coated magnetite (TA-Fe3O4) as an adsorbent. TA-Fe3O4 was synthesized using tannic acid, iron (II) sulfate heptahydrate, and iron (III) chloride hexahydrate through a one-pot co-precipitation method. The adsorbent material was then characterized using a scanning electron microscope coupled with an energy dispersive x-ray spectroscopy (SEM–EDS), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, zeta potential, and N2 adsorption–desorption (BET) techniques, confirming its successful synthesis. The maximum adsorption efficiencies for PS and PET were 83% and 98%, respectively, under the experimental conditions of pH 6–7, a contact time of 300 min, an adsorbent dose of 2.5 g/L, and an initial MPs concentration of 1.25 g/L. The study also found that the presence of ions in wastewater had a significant effect on MP recovery. However, when it came to recovering MPs from the spent adsorbent, the maximum values were observed in an acidic medium at pH 3–4 under sonification conditions. In conclusion, TA-Fe3O4 showed potential and efficiency in the recovery of MPs in aqueous media. However, further investigation is needed to improve the method and explore its application for multi-MPs recovery performance.

One-pot synthesis of amorphous/crystalline SnO2/BaSO4 composite sensitized with Eosin Y for enhanced photocatalytic H2 production

For the dye-sensitized heterogeneous photocatalytic system, the main challenge is the design of support materials with low cost, good adsorption capacity and facilitated electron transfer ability. Herein, an amorphous/crystalline SnO2/BaSO4 composite with unique leaf-like morphology composed of four protruded corners was developed by an one-pot coprecipitation method at room temperature. The low-cost crystalline BaSO4 acted as the support material for Eosin Y (EY) sensitization and did not inhibit the light absorption of EY, and the amorphous SnO2 uniformly coated on BaSO4 provided good conductivity to benefit for the transport of photogenerated carriers. Therefore, under visible-light irradiation (λ ≥ 420 nm), the EY-sensitized SnO2/BaSO4 showed excellent photocatalytic activity with H2-production rate of 263 μmol h−1, which was 7.5 times that of EY or EY-sensitized bare BaSO4, and the apparent quantum yield achieved to be 11.2 % at 500 nm.

Ethyl palmitate decarboxylation using colloidal SiO2- templated mesoporous Ni-ZrO2 catalysts

A series of 10 wt% NiO-xSiO2-ZrO2 (x = 0–30 wt%) catalysts were synthesized using a one-pot coprecipitation method with different of colloidal SiO2 contents, as a hard template, in order to imprint mesoporous cavities after a post-synthesis selective alkaline NaOH/H2O lixiviation. The final catalysts were characterized by XRD, HRTEM, textural measurements, 29Si-MAS NMR, FTIR, and XPS; the lixiviated, calcined and H2-reduced powders, were evaluated in the decarboxylation (DCO2) of ethyl palmitate as a liquid-solid phase model reaction at 300 °C, and 20 kg/cm2 H2 pressure. Optimal amount of colloidal SiO2 was 10 wt%. SiO2 effect (as colloid in fresh preparations and/or residual SiO2, after lixiviation) on ZrO2 is twofold. (i) to upgrade mesoporosity and (ii) to stabilize the porous structure. Residual SiO2 (from incomplete lixiviation) plays a beneficial role as examined by 29Si-NMR, being chemically bonded to ZrO2 and acting as props of the mesopores. Total pore volume and specific surface area values increased 5 and 6 times, respectively, when using a 30 wt% SiO2 in comparison with a non-silicated NiO-ZrO2 preparation. DCO2 of ethyl palmitate benefit from better mesoporosity and a great number of oxygen vacancies from Ni isomorphic substitution into cubic ZrO2 (as indicated by XPS); being at the origin of the reaction mechanism. For instance, a 10 wt% SiO2 NiO-ZrO2 catalyst is 1.6 times more selective (to n-pentadecane) and 1.2 times more active than a non-silicated NiO-ZrO2, yielding decarboxylated (i.e., deoxygenated) renewable linear hydrocarbons similar to those in a Diesel composition. However, DFT calculations indicate that adsorbed CO2 (as a formate species) desorbs, once fully hydrogenated, as methane regenerating the oxygen vacancies but consuming H2 as well, in agreement with the high methane concentration detected in gas phase.

One Pot Synthesis of Nanofiber-Coated Magnetic Composites as Magnetic Dispersive Solid-Phase Extraction Adsorbents for Rapid Determination of Tetracyclines in Aquatic Food Products.

A magnetic adsorbent based on a C-nanofiber (Fe3O4@C-NFs) nanocomposite was synthesized using a simple one-pot co-precipitation method. The characterized results showed that the obtained C-nanofiber-coated magnetic nanoparticles had many attractive features such as a large specific surface area and a highly interwoven and branched mesoporous structure, as well as distinguished magnetism. The nanocomposite was then used as an adsorbent in the magnetic solid phase extraction (MSPE) of four typical tetracyclines (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in aquatic products. The TCs in the extract were determined using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Experimental variables of MSPE, including the sorbent amount, pH condition, adsorption and desorption time, and desorption solvent, were investigated and optimized systematically. The method validation indicated that the developed method showed good linearity (R2 > 0.995) in the range of 1.0-200 ng/mL. The average recoveries at the spiked levels ranged from 90.7% to 102.7% with intra-day and inter-day relative standard deviations (RSDs, n = 6) ranging from 3.72% to 8.17% and 4.20% to 9.69%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the four kinds of TCs were 0.7 μg/kg and 2.0 μg/kg, respectively. Finally, MSPE based on C-nanofiber-coated magnetic nanoparticles was successfully applied to TC analysis in real aquatic products (grass carp, large yellow croaker, snakehead, mandarin fish, Penaeus vannamei, swimming crab, etc.). Compared with traditional extraction methods, the proposed method for TC analysis in aquatic products is more sensitive, effective, recyclable, and environmentally friendly.

Enhanced removal performance of magnesium-modified biochar for cadmium in wastewaters: Role of active functional groups, processes, and mechanisms

In this study, a series of biochar products with different active functional groups were developed by one-pot coprecipitation method, including magnesium-modified biochar (MgBC) and functional group-grafted MgBC (Cys@MgBC, Try@MgBC, and Glu@MgBC), for effective adsorption of cadmium (Cd(II)) from wastewaters. These biochars exhibited excellent removal performance for Cd(II), particularly Cys@MgBC, whose maximum Cd(II) adsorption capacity reached 223.7 mg g−1. The highly active and weakly crystalline Mg could adsorb Cd(II) through precipitation and ion exchange, which was further promoted by the introduced functional groups through complexation and precipitation. After 120 d of natural process, the immobilization efficiency of Cd(II) by Cys@MgBC, Try@MgBC, and Glu@MgBC was still maintained at 98.7%, 95.2%, and 82.7% respectively. This study proposes and clarifies the complexation mechanism of functional group-grafted Mg-modified biochar for heavy metals, providing new insights into the practical application of these biochars.

Dual-S-scheme 3D Ag2CO3/BiOI/BiOCl microsphere heterojunction for improving photocatalytic mercury removal

A novel 3D microspherical Ag2CO3/BiOI/BiOCl heterojunction photocatalyst was successfully prepared via a one-pot coprecipitation method. The pore characteristics, morphologies and optical properties of the composite photocatalysts were characterized in detail by means of XRD, FTIR, SEM, TEM, UV–Vis DRS, N2 adsorption-desorption, XPS, ESR and PL. The effects of the CO32−/Bi3+ molar ratio, pH value, fluorescent lamp irradiation, SO2, NO and scavengers on the wet removal of gaseous Hg0 by the composites were studied through a series of experiments. The results showed that more than 98% of Hg0 from simulated flue gas was removed by the optimized 3% Ag2CO3–BiOI/BiOCl system within 60 min. The photocatalyst had good acid, alkali and NO resistance, but SO2 significantly inhibited it. The specific surface area of the Ag2CO3/BiOI/BiOCl photocatalyst was much higher than that of a single component, which was 6.80 and 1.56 times that of Ag2CO3 and BiOI/BiOCl, respectively. For 3% Ag2CO3–BiOI/BiOCl, the Hg0 removal efficiency remained at approximately 94% in the sixth cycle. Density functional theory (DFT) revealed that the formation of heterojunctions could enhance the electron transition and efficient separation of photoinduced electron-hole pairs. Furthermore, the free radical capture experiment showed that anionic superoxide radical (•O2−) was the main active substance for the removal of Hg0. A reasonable dual-S-scheme charge transfer mechanism for an enhanced photocatalytic removal of Hg0 is proposed.

Synergistic Action between Copper Oxide (CuO) Nanoparticles and Anthraquinone-2-Carboxylic Acid (AQ) against Staphylococcus aureus

Infections linked to Staphylococcus spp. are difficult to treat with current antibiotic therapy, resulting in increased antibiotic resistance populations. One of the leading strategies to overcome this issue is the novel combination of antibacterial nanoparticles (NPs) and sustainable natural compounds. This study reported the identification of a new synergistic combination of copper oxide (CuO) NPs, a well-known antibacterial agent against Staphylococcus spp., and anthraquinone-2-carboxylic acid (AQ), a plant-derived antimicrobial compound, with a potent and specific fashion in killing Staphylococcus spp. CuO NPs were synthesized using the one-pot coprecipitation method and characterized by using X-ray diffraction and transmission electron microscopy. Further checkerboard analysis showed that CuO NPs and AQ increased the antibacterial activity of individual agents against Staphylococcus aureus among Staphylococcus spp. by four- to eightfold compared to individual materials. Additional mechanistic studies on the synergy revealed that the inhibition of biofilm formation and loss of cytoplasmic volume with cell shrinkage are the major actions of the combination in expressing the phenotype. This study clearly showed that the combination of CuO NPs and AQ would be a novel strategy to eradicate S. aureus infections.

Photocatalytic Evaluation of the Ternary Composite CdSO4-ZnAl LDH/ZnS in Hydrogen Production without a Sacrificial Reagent

In this work, a layered double hydroxide support modified with cadmium was synthesized by a one-pot coprecipitation method. Then, it was sulfured in different percentages by a solvothermal method. Next, the samples were analyzed using various characterization techniques like XRD, DRS, FTIR, N2 physisorption, PL spectroscopy, TEM, and SEM. Finally, the synthesized and uncalcined materials were assessed in hydrogen production from water and a methanol-water solution under UV-light irradiation. The results showed that the sulphuration improves the photocatalytic activity, reaching a maximum rate constant of hydrogen production of 7403 µmol/g∙h in a methanol-water solution and 1326 µmol/g∙h in water.

Ultra-Highly Active Ni-Doped MOF-5 Heterogeneous Catalysts for Ethylene Dimerization.

Here, an ultra-highly active Ni-MOF-5 catalyst with high Ni loading for ethylene dimerization is reported. The Ni-MOF-5 catalysts are synthesized by a facile one-pot co-precipitation method at room temperature, where Ni2+ replaces Zn2+ in MOF-5. Unlike Zn2+ with tetrahedral coordination in MOF-5, Ni2+ is coordinated with extra solvent molecules except for four-oxygen from the framework. After removing coordinated solvent molecules, Ni-MOF-5 achieves an ethylene turnover frequency of 352000h-1 , corresponding to 9040g of product per gram of catalyst per hour, at 35°C and 50bar, far exceeding the activities of all reported heterogeneous catalysts. The high Ni loading and full exposure structure account for the excellent catalytic performance. Isotope labeling experiments reveal that the catalytic process follows the Cossee-Arlman mechanism, rationalizing the high activity and selectivity of the catalyst. These results demonstrate that Ni-MOF-5 catalysts are very promising for industrial catalytic ethylene dimerization.

NiCo2O4 nano-needles as an efficient electro-catalyst for simultaneous water splitting and dye degradation.

Developing an efficient and non-precious bifunctional catalyst capable of performing water splitting and organic effluent degradation in wastewater is a great challenge. This article reports an efficient bifunctional nanocatalyst based on NiCo2O4, synthesized using a simple one-pot co-precipitation method. We optimized the synthesis conditions by varying the synthesis pH and sodium dodecyl sulfate (SDS) concentrations. The prepared catalyst exhibited excellent catalytic activity for the electrochemical oxygen evolution reaction (OER) and simultaneous methylene blue (MB) dye degradation. Among the catalysts, the catalyst synthesized using 1 g SDS as a surfactant at 100 °C provided the highest current density (658 mA cm-2), lower onset potential (1.34 V vs. RHE), lower overpotential (170 mV @ 10 mA cm-2), and smallest Tafel slope (90 mV dec-1) value. Furthermore, the OH˙ radicals produced during the OER electrochemically degraded the MB to 90% within 2 hours. The stability test conducted at 20 mA cm-2 showed almost negligible loss of the electrochemical response for OER, with 99% retention of the original response. These results strongly suggest that this catalyst is a promising candidate for addressing the challenges of wastewater treatment and energy generation.

Influence of capping agents on fraction of Fe atoms occupying octahedral site and magnetic property of magnetite (Fe3O4) nanoparticles by one-pot co-precipitation method

Magnetite (Fe3O4) nanoparticles were synthesized by one-pot coprecipitation method using five different capping agents: Sodium citrate, Poly vinyl pyrrolidone (PVP), Chitosan, Cetyltrimethylammonium bromide (CTAB) and Citric acid. The influence of the various capping agents on the size, oxidation and fraction of Fe atoms occupying Octahedral against Tetrahedral sites in relation to the saturation magnetization (Ms) of the magnetite nanoparticles were studied. X-ray Absorption Fine Structure (XAFS) spectroscopy, X-ray Absorption Near Edge Structure (XANES), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier-Transform Infra-Red (FTIR) spectroscopy, Zeta potential, and Vibrating Sample Magnetometery (VSM) are used to study the various effects. The results reveal that the capping agents affect the size, oxidation and ratio of Fe atoms occupying octahedral vs tetrahedral site. The graph of Ms against size, oxidation and fraction of Fe atoms are plotted. Statistical analysis shows that Ms of the magnetite nanoparticles is highly dependent on the fraction of Fe atoms and the Size of the nanoparticles. The results reveal the Ms increases with size of the nanoparticles but decreases with the fraction of Fe atoms occupying octahedral vs tetrahedral site. However, there is no direct correlation between oxidation of Fe and Ms.

Promotional mechanism of activity of CeEuMnOx ternary oxide for low temperature SCR of NOx

Due to strong synergistic effect of the elements, a series of XEuMnOx ternary oxides (X = Ce, Ni, Co, Sb, Sn, Mo) were synthesized by one-pot co-precipitation method, and composite components were identified and optimized to maintain high activity and superior SO2 and H2O endurance in selective catalytic reduction of NOx with NH3 (NH3-SCR). NOx conversion of CeEuMnOx ternary oxide catalysts attains more than 90% at 100–250 °C, and finally achieves 74% under existence of 50 × 10−6 SO2 and 10 vol% H2O at 230 °C. The facile electron transfer through redox cycle of Mn3+ + Ce4+ ↔ Mn4+ + Ce3+ and enhanced oxygen mobility can promote formation of more Mn species in high oxidation state and chemisorbed oxygen, accelerating oxidation of NO and the adsorbed NO2 formed can facilitate “fast SCR” reaction to improve low-temperature activity. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study reveals that addition of Ce to EuMnOx catalyst boosts adsorption of NH3 and NOx species. NH3 species are activated as crucial intermediate (NH2) to promote NH3-SCR reaction. This research provides a novel material for practical deNOx application of stationary source combustion flue gas in the future.

Facile synthesis of NiO-SnO2 nanocomposite for enhanced photocatalytic degradation of bismarck brown

• The n-n type NiO-SnO 2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. • Bismarck brown dye was photodegraded with an efficiency of 98 % in 70 mins under irradiation of sunlight. • The degradation showed pseudo-first-order kinetics with a rate constant of 4.5 × 10 -2 min −1 . • The photodegradation obeyed the Langmuir-Hinshelwood isotherm model. • The fabricated nanocomposite showed reusability up to 8 times. The n-n type NiO-SnO 2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. The fabricated NiO-SnO 2 nanocomposite was employed as a photocatalyst to degrade bismarck brown dye under direct sunlight. TEM, SAED, XRD, XPS, EDX, FTIR, and UV spectra have been recorded to characterize the synthesized NiO-SnO 2 nanostructures. TEM studies found that the average particle size was 11 nm, and the SAED confirmed the polycrystalline nature of the synthesized nanocomposite. It was found that 98 % of 20 mg/L bismarck brown dye was degraded by 20 mg/L of photocatalyst within 70 min irradiation of sunlight at an optimum pH of 11. Further studies showed that the degradation followed pseudo-first-order kinetics with a rate constant of 4.5 × 10 -2 min −1 and obeyed the Langmuir-Hinshelwood isotherm model. The fabricated NiO-SnO 2 nanocomposite was reusable up to 8 times; hence, it proved to be an efficient catalyst for the photodegradation of bismarck brown dye.

Facile fabrication of 3D spherical Ag2WO4 doped BiOI/BiOCl double S-scheme heterojunction photocatalyst with efficient activity for mercury removal

The novel ternary Ag2WO4/BiOI/BiOCl microspherical photocatalysts were successfully fabricated by a facile one-pot coprecipitation method to accelerate the separation performance of photogenerated electron-hole (e–-h+) pairs of BiOCl and BiOI materials. The as-prepared materials were characterized by multiple methods, and the effects of various parameters such as Ag2WO4 content, fluorescent light irradiation, pH value and inorganic anions on photocatalytic removal of Hg0 were studied in detailed. The characterization results showed that the three-dimensional (3D) microspherical BiOI/BiOCl composite provided a suitable carrier for Ag2WO4, and Ag2WO4 material was evenly dispersed on the Ag2WO4/BiOI/BiOCl surface. The ternary composite possessed a larger surface area than Ag2WO4 and BiOI/BiOCl with the addition of Ag2WO4. Meanwhile, the separation efficiency of e–-h+ pairs in Ag2WO4/BiOI/BiOCl composite was greatly enhanced. The experimental results showed that Ag2WO4 content, fluorescent light irradiation, CO32− and SO2 all exhibited remarkable influences in the photocatalytic process. The Hg0 removal efficiency of Ag2WO4/BiOI/BiOCl photocatalyst was still up to 94 % after four cycles, indicating a superior stability of photocatalyst. Superoxide radical (•O2–) and hole (h+) were proved to be the main reaction substances for Hg0 removal. In view of the characterization analysis, free radicals capture test results and Density functional theory (DFT) calculation, the charge transfer route of Ag2WO4/BiOI/BiOCl composite and its mechanism for gaseous Hg0 removal were proposed with a double S-scheme mode.

Core-multishell lanthanide-doped nanocomposite by one-pot synthesis for NIR-II emissions-based temperature sensing

The performances of nanothermometers based on visible light are inevitably degraded in biological applications because visible light is greatly weakened after passing through tissues. Herein, in view of the second biological optical transparency window, a type of tailored core-multishell lanthanide-doped nanocomposite was synthesized with facile one-pot coprecipitation method to supplant complex method demanding stepwise thermal decomposition. Proved to have excellent dispersibility, crystallinity, stability and luminous efficiency, the nanocomposite is capable of enhanced NIR-II emissions and a broad temperature detection scope based on three kinds of spectral parameters relevant to its unique core-multishell structure. The maximum absolute and relative sensitivity of luminescence intensity ratios in low temperature range can reach up to 11.3% K−1 and 1.27% K−1, respectively, and a theoretical derivation is provided to address the peculiar V-shaped trend of NIR-II luminescence lifetime. The prepared nanocomposite can serve as a promising candidate for optical thermometer in the fields of cryoablation of diseased tissues and industrial applications in strong magnetic or radiofrequency fields.

Fabrication of ZnO–SnO2 nanocomposite and its photocatalytic activity for enhanced degradation of Biebrich scarlet

The n-n-type ZnO-SnO2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. The fabricated ZnO-SnO2 nanocomposite was employed as a photocatalyst in the degradation of Biebrich scarlet dye under UV254 light. TEM, SAED, XRD, XPS, EDX, FTIR, and UV spectra have been recorded to characterize the synthesized ZnO-SnO2 nanostructures. TEM studies found that the average particle size was 10-12nm, and the SAED confirmed the polycrystalline nature of the synthesized nanocomposite. It was found that 97% of 10mg/L Biebrich scarlet dye was degraded by 25mg/L of photocatalyst within 40-min irradiation of UV254 light at an optimum pH of 6. Further studies showed that the degradation followed pseudo-first-order kinetics with a rate constant of 5.48 × 10-2min-1. The fabricated ZnO-SnO2 nanocomposite was reusable up to 8 times; hence, it proved to be an efficient catalyst for the photodegradation of Biebrich scarlet dye.

PH-responsive glycine functionalized magnetic iron oxide nanoparticles for SARS-CoV-2 RNA extraction from clinical sample.

The recent outbreak of the novel corona virus disease 2019 (COVID-19) has been made a serious global impact due to its high infectivity and severe symptoms. The Severe Acute Respiratory Syndrome (SARS-CoV-2) RNA extraction is considered as one of the most important steps in COVID-19 detection. Several commercially available kits and techniques are currently being used for specific extraction of SARS-CoV-2 RNA. However, such methods are time consuming and expensive due to the requirement of trained labors, and several chemical reagents. To overcome the mentioned limitations, magnetic RNA adsorption methodology of glycine functionalized iron oxide nanoparticles (GNPs) was established. It showed an efficient potential in SARS-CoV-2 RNA extraction due to pH responsive nature of GNPs. The highly magnetic pH responsive GNPs were synthesized by one-pot co-precipitation method. Random morphology and average 20 nm size of GNPs were denoted by Transmission Electron Microscopy (TEM). X-ray diffractometer (XRD) showed the crystalline magnetite nature. Fourier transform infrared spectroscopy (FT-IR) and UV–visible spectrometry confirmed the presence of glycine on the surface of magnetic nanoparticles. Furthermore, the magnetic nature and thermal properties of GNPs were examined by vibrating sample magnetometer (VSM) and thermo-gravimetric analysis (TGA), respectively. In this study, glycine performed the role of RNA adsorbent. The adsorption of RNA onto the surface of GNPs was achieved in acidic medium (pH 6). In contrary, the elution of RNA from the surface of GNPs was achieved in basic medium (pH 8). The purity of obtained RNA was analyzed by UV–visible spectrometry. Further, the obtained RNA was examined for the presence of SARS-CoV-2 specific Envelope (E), RNA dependent RNA polymerase (RDRP) and Nucleocapsid (N) genes using an RT-PCR analysis. It showed the sudden rise in amount of these genes after 25 cycles of RT-PCR and hence indicated the efficient RNA extraction by GNPs. Agarose gel electrophoresis was used for validation of the quantity and quality of RNA extracted from SARS-CoV-2 patient’s sample. The reusability studies of GNPs were performed by monitoring the repeated use of GNPs for SARS-CoV-2 RNA extraction. This method possesses potential role in the field of disease diagnosis. The extraction results of RNA from SARS-CoV-2 patient’s sample indicated that the GNPs have an outstanding property over the current existing extraction protocols. It leads to the new advancements in extraction and detection of RNA.Graphical Graphical abstract of the pH responsive SARS-CoV-2 RNA extraction by using glycine functionalized magnetic iron oxide nanoparticles (GNPs) which were prepared by modified cost effective one pot chemical synthesis method. Prepared GNPs were characterized by XRD, FT-IR and UV-Visible spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Glycine present on the surface of nanoparticles (NPs) played an important role in pH responsive RNA extraction procedure. When nanoparticles added in acidic (pH < 7) medium, glycine gained positive surface charge hence overall surface charge of NPs became positive. Thereby SARS-CoV-2 RNA adsorption/binding occurred on the surface of GNP. Later, the RNA-GNP complex was separated by an external magnet. Separated complex was added in basic (pH > 7) medium to elute RNA from GNP. This phenomenon occurred due to surface negative charge of glycine that caused charge repulsion with RNA. Eluted RNA was examined qualitatively and quantitatively by RT-PCR, nanodrop technique and agarose gel electrophoresis. Results were compared with kit based extracted RNA. Supplementary InformationThe online version contains supplementary material available at 10.1007/s10853-022-07464-6.

Silver nanoparticles anchored magnetic self-assembled carboxymethyl cellulose-ε-polylysine hybrids with synergetic antibacterial activity for wound infection therapy

The severe bacterial infection and chronic wound healing caused by the abuse of antibiotics threaten the public health, which calls the need for the development of novel antibacterial agents and alternative therapeutic strategies. Herein, magnetic carboxymethyl cellulose-ε-polylysine hybrids (FCE) were synthesized via a facile one-pot coprecipitation method and further used as matrix to anchor silver nanoparticles (Ag NPs). The as-resulted Ag/FCE hybrids were employed to inactivate pathogenic bacteria and accelerate bacteria-infected wound healing with the assistance of H2O2. In vitro investigation revealed the combination of hydroxyl radical (·OH) originated from low concentration of H2O2 catalyzed by Ag/FCE and the antimicrobial activity of Ag NPs endowed effective antibacterial performance to the hybrids against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Investigation on antibacterial mechanism indicated antibacterial activity of the synergetic strategy was achieved by destroying bacterial cell integrity, arresting metabolic, producing intracellular ROS, and oxidizing GSH. Additionally, in vivo assay exhibited Ag/FCE possessed satisfactory biocompatibility and effectively accelerated S. aureus-infected wound healing with the presence of low concentration of H2O2. Altogether, the presented results supported the great potential application of the synergistic antibacterial strategy for the therapy of bacterial-infected wound healing.

Angiogenic Hyaluronic Acid Hydrogels with Curcumin-Coated Magnetic Nanoparticles for Tissue Repair.

Angiogenic magnetic hydrogels are attractive for tissue engineering applications because their integrated properties can improve angiogenesis while providing magnetic guidance and stimulation for tissue healing. In this study, we synthesized magnetic nanoparticles (MNPs) with curcumin as an angiogenic agent, referred to as CMNPs, via a one-pot coprecipitation method. We dispersed CMNPs in hyaluronic acid (HyA) to create angiogenic magnetic hydrogels. CMNPs showed a slightly reduced average diameter compared to that of MNPs and a curcumin content of 11.91%. CMNPs exhibited a sustained slow release of curcumin when immersed in a revised simulated body fluid (rSBF). Both CMNPs and MNPs showed a dose-dependent cytocompatibility when cultured with bone marrow-derived mesenchymal stem cells (BMSCs) using the direct exposure culture method in vitro. The average BMSC density increased when the concentrations of CMNPs or MNPs increased from 100 to 500 μg/mL, but the cell density decreased when the nanoparticle concentration reached 1000 μg/mL. CMNPs showed a weaker magnetic response than MNPs both in air and in water immediately after synthesis but retained the magnetism better than MNPs when embedded in the HyA hydrogel because of less oxidation. CMNPs were able to respond to magnetic guidance even when the porcine skin or muscle tissues were placed in between the nanoparticles and external magnet. The magnetic hydrogels of HyA_CMNP and HyA_MNP promoted the adhesion of BMSCs in a direct exposure culture. The HyA_CMNP group also showed the highest secretion of the vascular endothelial growth factor with the release of curcumin in vitro. Overall, our magnetic hydrogels integrated the desirable properties of cytocompatibility and angiogenesis with magnetic guidance, thus proving to be promising for improving tissue regeneration.