查找使用阿拉丁产品的科研文献

Efficient removal of free and nitrilotriacetic acid complexed Cd(II) from water by poly(1-vinylimidazole)-grafted Fe3O4@SiO2 magnetic nanoparticles

Chao Shan,Zhiyao Ma,Meiping Tong

Poly(1-vinylimidazole)-grafted Fe 3 O 4 @SiO 2 magnetic nanoparticles (FSPV) were developed to remove both free Cd(II) and nitrilotriacetic acid (NTA) complexed Cd(II) from water. The adsorption capacity of NTA-complexed Cd(II) (42.1   mg/g) was larger than that of free Cd(II) (24.8   mg/g). Free Cd(II) and NTA-complexed Cd(II) could be reduced from 50   μg/L to below 5   μg/L within 10 and 20   min, respectively. FSPV could effectively remove trace free and NTA-complexed Cd(II) over broad pH ranges of 5–10 and 5–11, respectively. Moreover, the presence of seven coexisting ions (up to 100   mM) including four cations (Na + , K + , Ca 2+ , and Mg 2+ ) and three anions (Cl − , NO 3 − , and SO 4 2− ) all slightly promoted the removal of both free and NTA-complexed Cd(II) onto FSPV. The removal of free Cd(II) or NTA-complexed Cd(II) was not obviously affected by the presence of Ni(II) and Co(II) (50   μg/L), humic acid (up to 3   mg/L as TOC) or alginate (up to 8   mg/L as TOC). In addition, FSPV could be regenerated with 10   mM HCl in 10   min, and the removal of both types of Cd(II) maintained above 95% in five consecutive adsorption/regeneration cycles. Therefore, FSPV could be utilized as promising adsorbent for both free and NTA-complexed Cd(II).

A sandwich-type electrochemical immunosensor for carcinoembryonic antigen based on signal amplification strategy of optimized ferrocene functionalized Fe3O4@SiO2 as labels

Taotao Feng,Xiuwen Qiao,Haining Wang,Zhao Sun,Chenglin Hong

A sandwich-type electrochemical immunosensor was developed for sensitive detection of carcinoembryonic antigen (CEA) by using ferroferric oxide@silica–amino groups (Fe 3 O 4 @SiO 2 –NH 2 ) as carriers and gold nanoparticles–graphene oxide (GO–AuNPs) as platform. The Fe 3 O 4 @SiO 2 –NH 2 surface was used as linked reagents for co-immobilization of ferrocenecarboxylic acid (Fc-COOH) and secondary anti-CEA (Ab 2 ) to prepare the signal probe , and it also could hasten the decomposition of hydrogen peroxide (H 2 O 2 ) to amplify signals. Differential pulse voltammetry (DPV) was successfully used to quantify CEA. Under the optimized conditions, the designed immunosensor shows an excellent analytical performance wide dynamic response range of CEA concentration from 0.001   ng   mL −1 to 80   ng   mL −1 with a relatively low detection limit of 0.0002   ng   mL −1 ( S / N =3), and high specificity and good reproducibility. The proposed immunosensor was successfully used to determine CEA in spiked human serum samples.

Functionalized magnetic nanomaterials as recyclable adsorbents for efficient flavonoid enrichment in Scutellaria Radix

Guohua Teng,Hezhao Bai,Chen Zhang,Jingyi Yang,Xiaoye Wang,Yu Zhu,Fei Tian

A magnetic composite (Fe 3 O 4 @SiO 2 @PNIPAM-co-NHMA) with high adsorption capacity and recoverability was developed for the enrichment and determination of flavonoids in Scutellaria Radix ( SR ). A magnetic solid-phase extraction (MSPE) technique using Fe 3 O 4 @SiO 2 @PNIPAM-co-NHMA absorbent in combination with high-performance liquid chromatography (HPLC) was developed for selectively enrichment and determination of the biologically active flavonoids in the aqueous extract of SR , including baicalein, baicalin, wogonoside and wogonin. Under the optimized experimental conditions, the magnetic adsorbent could adsorb up to 77.0 ± 0.98 % − 98.15 ± 0.15 % of four representative flavonoids from SR , with elution rates varying from 55.10 ± 0.25 % to 91.94 ± 1.85 %. The limits of detection (LOD) and limits of quantitation (LOQ) were 0.01–0.35 μg/mL and 0.03–0.98 μg/mL, respectively. In addition, it remained effective after six replicates, demonstrating its potential as a recoverable adsorbent for enriching flavonoids in traditional Chinese medicine.

Determination of 25 quinolones in water and milk by a magnetic sorbent Fe3O4@SiO2-HBTA-TTA-COF combining with UPLC-MS/MS

Weihao Ma,Hao Zhang,Jiayuan Nie,Chunyu Qiang,Zhiwei Li,Ling Ma,Ke Wang

In this study, a novel magnetic covalent organic framework (Fe 3 O 4 @SiO 2 -HBTA-TTA-COF) was synthesized, which was fully characterized by scanning electron microscopy, transmission electron microscopy, etc. Furthermore, a new method was developed for the determination of 25 quinolones (QNs) in water and milk using the Fe 3 O 4 @SiO 2 -HBTA-TTA-COF as magnetic solid-phase extraction adsorbent coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Meanwhile, various experimental parameters were optimized including sample solution pH, adsorbent dosage and extraction time, etc. Under the optimal conditions, good linearity in the range of 0.1–200 μg·L −1 (R 2  ≥ 0.999) were obtained, the recoveries of 25 QNs were 70.04 %–104.4 % with the relative standard deviations lower than 9.87 % (n = 5), the limits of detection were 0.003–0.010 μg·L −1 for water and 0.018–0.722 μg·kg −1 for milk. This established method was high-sensitive and high-throughput, which can be used as a good alternative method for the selective determination of 25 QNs in water and milk.

Facile Preparation of Fe3O4@SiO2 Derived from Iron-Rich Sludge as Magnetic Catalyst for the Degradation of Organic Contaminants by Peroxymonosulfate Activation

Zhiwei Wang,Shijun Zhu,Jing Deng,Haojie Li,Liang Wang,Haojin Luo,Zehe Tang,Xueyan Li

Iron-rich sludge, generated during flocculation/sedimentation processes by using Fe-based coagulant in drinking water treatment plants, could be used as a precursor to prepare an effective peroxymonosulfate (PMS) activator (Fe3O4@SiO2) for the ciprofloxacin (CIP) degradation via facile hydrothermal treatment. The catalytic performances of raw iron-rich sludge and Fe3O4@SiO2were evaluated. The removal rate of CIP in Fe3O4@SiO2/PMS system increased from 44.7% to 82.8% within 60 min compared with the raw iron-rich sludge. The effects of PMS, catalyst loadings, temperature, and initial pH on the CIP degradation were examined, demonstrating that acidic conditions and higher temperatures were beneficial for CIP degradation. Both sulfate radicals (SO4•−) and hydroxyl radicals (•OH) contributed to the CIP degradation, and SO4•−was predominated in the Fe3O4@SiO2/PMS system, which was confirmed by the result of electron paramagnetic resonance (EPR) analysis and radical quenching tests. The mechanisms of the PMS activation process by Fe3O4@SiO2were elucidated, and the influencing factors were among which the role of the iron mineral phase was emphatically explored. This study provides a facile method to convert the recycled waste iron-rich sludge to magnetic heterogeneous catalysts for CIP degradation with PMS activation.Keywords:iron-rich sludge;Fe3O4@SiO2catalyst;peroxymonosulfate activation;ciprofloxacin;waste recycling

Efficient Conversion of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid by the Magnetic Laccase Nanoflowers-2,2,6,6-Tetramethylpiperidin-1-Oxyl System

Lei Yang,Anbang Duan,Zhanyin Liu,Tingying Wei,Chunzhao Liu

Aiming to address the key challenges of poor enzyme stability, difficult recovery, and difficult synergistic optimization of catalytic efficiency in high-value conversion of biomass, this study utilizes mineralization self-assembly technology to combine laccase with Fe3O4@SiO2-PMIDA-Cu2+composite, constructing magnetic laccase nanoflower (MLac-NFs) materials with a porous structure and superparamagnetism. This synthetic material can efficiently catalyze the selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The characterization results indicated that MLac-NFs exhibit optimal catalytic activity (63.4 U mg−1) under conditions of pH 6.0 and 40 °C, with significantly enhanced storage stability (retaining 94.26% of activity after 30 days of storage at 4 °C). Apparent kinetic analysis reveals that the substrate affinity and maximum reaction rate of MLac-NFs were increased by 38.3% and 439.6%, respectively. In the laccase–mediator system (LMS), MLac-NFs mediated by 30 mM TEMPO could achieve complete conversion of HMF to FDCA within 24 h. Moreover, due to the introduction of magnetic nanoparticles, the MLac-NFs could be recovered and reused via an external magnetic field, maintaining 53.26% of the initial FDCA yield after six cycles.

Multifunctional boronic acid-functionalized magnetic nanohybrid: An efficient and selective adsorbent of cis-diol-flavonoids

FuKai Li,Min Wang,Jian Zhou,MengRui Yang,TongTong Wang

A novel magnetically and efficiently multifunctional boronic acid (BA) -functionalized core-shell nanohybrid (Fe 3 O 4 @SiO 2 @BA) was prepared for capture and separation of cis -diol-flavonoids. The morphology and physicochemical properties of resultant nanoparticles were systematically characterized via several techniques, and the results confirmed that the target nanohybrids were successfully functionalized and modified. Meanwhile, two flavonoids (quercetin and luteolin) were selected to investigate the selective capture of the Fe 3 O 4 @SiO 2 @BA in procedure of magnetic solid phase extraction (MSPE). The main parameters influencing the adsorption and elution conditions were systematically investigated and optimized. Furthermore, the adsorption kinetic models were adopted to elucidate the adsorption process , indicating that the pseudo-second-order model was suitable to explain the adsorption kinetics. Under the optimum conditions, the MSPE-HPLC-MS/MS approach was established with a wide linear dynamic range and good linearity (R 2  ​> ​0.999), low limits of detection (0.0096–0.033 ​μg ​L −1 ) and satisfactory recoveries (91–107.6%). The proposed analytical method was successfully applicated by determining the content of target flavonoids in food samples (apple and onion). Accordingly, the prepared nanohybrid could serve as an efficient, rapid and economical potential adsorbent for extracting cis -diol-flavonoids in complex food samples.

4D-printed dual-responsive bioscaffolds for treating critical-sized irregular bone defects

Yangyang Li,Jiaqian You,Huixin Lv,Chong Wang,Shaobo Zhai,Sicong Ren,Xiuyu Liu,Yidi Zhang,Yanmin Zhou

Currently, treating irregular bone defects with a critical size is still challenging as material implantation in the complex defects with irregular shapes, effective osteogenesis and sufficient vascularization cannot be easily achieved simultaneously via a simple strategy. Herein, a dual-responsive bone tissue engineering scaffold is developed using a 4D printing strategy by intergrating a single type of multifunctional magnetic nanoparticles, Fe 3 O 4 @SiO 2 , with printing inks made of bioceramics and biopolymers. Minimally invasive implantation, fluent navigation of scaffolds as well as the precise boundary matching between scaffolds and the irregular defects are achieved through near-infrared (NIR) irradiation-based temperature responsive shape recovery and static magnetic field (SMF) stimulation. Moreover, improved bone regeneration in critical-sized bone defects is successfully achieved through the activation of PI3K/AKT pathway which significantly promotes osteogenic differentiation and vascularization. Besides, NIR-based photothermal stimulation upregulates the expression of heat shock protein (HSP90) and further promotes the osteogenesis and vascularization. The in vivo study also confirms that our scaffold can precisely fit the bone defect, and induce satisfactory osteogenesis and angiogenesis. This work provides a facile strategy to simultaneously-realize easy scaffold implantation in irregular bone defects and improves osteogenesis and angiogenesis by integrating a single type of multifunctional nanoparticles with scaffold matrices.

Octadecylimidazolium ionic liquid-modified magnetic materials: Preparation, adsorption evaluation and their excellent application for honey and cinnamon

Houmei Liu,Zhan Li,Makoto Takafuji,Hirotaka Ihara,Hongdeng Qiu

A novel and versatile adsorbent based on 1-octadecylimidazolium ionic liquid modified magnetic nanoparticles (Fe 3 O 4 @SiO 2 @ImC18) possessing of both magnetic property and excellent adsorption ability was successfully synthesized. Twelve compounds from four kinds of substances (alkylbenzenes, PAHs, flavonoids and organic acids) were chosen as probe molecules to evaluate adsorption properties of the new adsorbent. A series of adsorption experiments were conducted and results indicated both synergism and competition effects were existed and multiple interactions took place during adsorption process. After considerable acquaintances with the adsorbent, it was successfully applied for real samples analysis of honey and cinnamon. Three flavonoid compounds of myricetin, quercetin and luteolin from honey and cinnamic acid from cinnamon were all detected and quantified. Meanwhile, it reached 280-fold concentration reduction of interferent during the extraction of cinnamic acid from cinnamon. The recoveries were in the range of 85.4–94.8% with relative standard deviations ( n   =   3) of 2.5–5.6%.The current study not only provided a strategy to evaluate new adsorbent, but also demonstrated the novel Fe 3 O 4 @SiO 2 @ImC18 material was reliable, accurate and suitable for sample pretreatment in pharmaceutical and food chemistry.

Core-shell magnetic molecularly imprinted polymers based on Fe3O4@SiO2–C = C carrier for selective adsorption and rapid detection of ibuprofen in environment

Junxia Chai,Hongbo Mo,Chuan Wang,Fengjie He,Jufen Huang,Li Ran,Weigang Fan,Yuepeng Fan,Fan Lu

This study developed Fe3O4@SiO2–C = C-based magnetic molecularly imprinted polymers for selective ibuprofen removal and detection. The optimized synthesis using an ibuprofen (IBP)/(3-aminopropyl)triethoxysilane (APTES)/tetraethyl orthosilicate (TEOS) molar ratio of 1:6:18 achieved a high adsorption capacity of 68.18 mg·g−1 and an imprinting factor of 2.17. The adsorption process followed pseudo-second-order kinetics and the Freundlich isotherm model, indicating multilayer binding behavior. The material demonstrated excellent reusability with only 2.8% capacity loss after five cycles and good reproducibility with a relative standard deviation of 4.48%. In magnetic solid-phase extraction applications, the recovery rate reached 81.61% to 96.40% for real water samples with a detection limit of 0.09 μg·mL−1. The polymers showed selective recognition of ibuprofen over structural analogs due to synergistic π-π interactions and hydrogen bonding, thus offering an efficient strategy for remediating pharmaceutical pollutants in water.

Biogenic synthesis of ferrous(III) oxide and Fe3O4/SiO2 using Chlorella sp. and its adsorption properties of water contaminated with copper(II) ions

Shireen Ibrahim Hamadamin,Sewgil Saaduldeen Anwer,Parween Mohsin Abdulkareem,Kwestan Hassan Sdiq

Novel magnetically separable anhydride-functionalized Fe3O4@SiO2@PEI-NTDA nanoparticles as effective adsorbents: synthesis, stability and recyclable adsorption performance for heavy metal ions

Chaoyang Jia,Junhong Zhao,Liling Lei,Xiyang Kang,Ran Lu,Chongtao Chen,Shunling Li,Yale Zhao,Qingxiang Yang,Zhijun Chen

In this paper, a novel adsorbent, Fe3O4@SiO2@PEI-NTDA, was first prepared by the immobilization of an amine and anhydride onto magnetic Fe3O4@SiO2 nanoparticles with polyethylenimine (PEI) and 1,4,5,8-naphthalenetetracarboxylic-dianhydride (NTDA) for the removal of heavy metal ions from aqueous solutions. The structure of Fe3O4@SiO2@PEI-NTDA was systematically investigated; the results confirmed that amine and anhydride groups were successfully covalently grafted onto the surface of Fe3O4@SiO2, which showed a homogenous core–shell structure with three layers of about 300 nm diameter (Fe3O4 core: 200 nm, nSiO2 layer: 20 nm, and PEI-NTDA layer: 20 nm). The adsorption performance of Fe3O4@SiO2@PEI-NTDA NPs was evaluated for single Pb2+ and coexisting Cd2+, Ni2+, Cu2+, and Zn2+ ions in an aqueous solution in a batch system. The amine and anhydride groups may have a synergistic effect on Pb2+ removal through electrostatic interactions and chelation; Fe3O4@SiO2@PEI-NTDA NPs exhibited preferable removal of Pb2+ with maximum adsorption capacity of 285.3 mg g−1 for Pb2+ at a solution pH of 6.0, adsorbent dosage of 0.5 g L−1, initial Pb2+ concentration of 200 mg L−1 and contact time of 3 h. The adsorption mechanism conformed well to the Langmuir isotherm model, and the adsorption kinetic data were found to fit the pseudo-second order model. Fe3O4@SiO2@PEI-NTDA NPs could be recovered easily from their dispersion by an external magnetic field and demonstrated good recyclability and reusability for at least 6 cycles with a high adsorption capacity above 204.5 mg g−1. The magnetic adsorbents showed high stability with a weight loss below 0.65% in the acid leaching treatment by 2 M HCl solution for 144 h. This study indicates that Fe3O4@SiO2@PEI-NTDA NPs are new promising adsorbents for the effective removal of Pb2+ in wastewater treatment.