查找使用阿拉丁产品的科研文献

A novel enrichment and sensitive method for simultaneous determination of 15 phthalate esters in milk powder samples

Jin-Kui Ma,Shou-Lian Wei,Qing Tang,Xiao-Chen Huang

Phthalate acid esters (PAEs) with superior performance are widely used. However, the long-term intake of PAEs seriously damages the human body. In this work, a novel type of magnetic molecularly imprinted polymer (mMIP) was synthesized and coupled with gas chromatography–mass spectrometry (GC/MS) for the selective separation and determination of 15 PAEs in milk powder samples. Key mMIP variables, i.e. (1) NaCl dosage, (2) eluent type and amount, (3) extraction and elution time), and (4) reusability, were investigated to determine the optimal magnetic solid phase extraction conditions. Results revealed that the mMIPs had good recognition specificity for the template molecules. Under the optimized conditions, 15 PAEs were successfully separated and analyzed by GC/MS. Results showed a good linearity in the range of 0.05–10.0 μg/mL for different PAEs’ concentration. The detection limit was 0.2–0.8 μg/kg, the average recovery was 83.0%–104%, and the relative standard deviation was 2.4 %–8.6% ( n  = 5). This new sample and rapid pretreatment method was successfully applied to the monitoring of trace plasticizing agent residues in milk powder.

ZIF-L Derived Bimetallic N-Doped Porous Carbon-Prussian Blue Composite as Efficient Catechol Electrochemical Sensor

Ziyu Zhao,Jialun Luo,Simon Tricard,Jihua Zhao,Qiangming Wang,Jian Fang

The development of effective and accurate catechol (CC) electrochemical sensors is critical for environment and life health perspectives. A facile pyrolysis of 2D bimetallic (Zn/Co) zeolitic imidazolate framework (Zn/Co-ZIF-L) was employed to prepare Zn and Co nanoparticles encapsulated in N-doped porous carbon (Zn/Co@NPC). Prussian blue (PB) was synthesized in situ via the co-precipitation of ferricyanide ([Fe(CN)6]3−) and iron (II) ion originated from the reduction of Fe3+ by Zn/Co@NPC and then served as the main active substance of CC detection. The morphology and composition of the final composite Zn/Co@NPC-PB were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The Zn/Co@NPC-PB modified glass carbon electrode (GCE) exhibits two concentration linear ranges of 4.13 μM − 1.08 mM (R2 = 0.999) and 1.08 mM−11.82 mM (R2 = 0.999) for CC electrochemical detection with a limit of detection 1.05 μM (S/N = 3). At the same time, the Zn/Co@NPC-PB/GCE shows great selectivity to electrochemical oxidation behavior of CC in presence of 20 folds dihydroxybenzene interferents such as hydroquinone and resorcinol. Furthermore, it showed a long-term stability and near 100% recovery for the detection of a real sample in Yellow River water.

Selenium improved the combined remediation efficiency of Pseudomonas aeruginosa and ryegrass on cadmium-nonylphenol co-contaminated soil

Gang Ni,Guangyu Shi,Chengxiao Hu,Xu Wang,Min Nie,Miaomiao Cai,Qin Cheng,Xiaohu Zhao

Most chemical plant wastewater contains both organic and inorganic pollutants , which are easy to diffuse along with surface runoff. The combined pollution of nonylphenol (NP) and cadmium (Cd) in soil is a serious problem that has not attracted enough attention. Based on the effects of selenium (Se) and Pseudomonas aeruginosa ( P. aeruginosa ) on plant and soil microbial communities , we speculated that the application of Se and P. aeruginosa in soil could improve the phytoremediation efficiency of ryegrass on contaminated soil. In this study, pot experiments with Cd and NP co-contaminated soil were conducted, and the results showed that application of P. aeruinosa alone could improve the removal rates of NP and Cd by ryegrass, and the supplementary of Se further enhanced the effect of micro-phyto remediation, with the highest removal rates of NP and Cd were 79.6% and 49.4%, respectively. The application of P. aeruginosa plus Se reduced the adsorption of Cd and NP through C–O and Si–O–Fe of the soil, changed the enzyme activity , and also affected the changing trend of the microbial community in soil. Pseudomonas , Sphingomonadales , Nitrospira , and other beneficial bacteria were enriched after a 60-day period with P. aeruginosa and Se treatment, thus promoting the removal of NP and Cd. In light of the above results, we suggest that P. aeruginosa application can efficiently facilitate the phytoremediation of ryegrass on Cd-NP co-contaminated soil, and Se supplementation in soil showed the synergistic effect on the remediation.

A pH-responsive fluorometric and colorimetric system based on silicon quantum dots and 4-nitrophenol for urease activity detection

Jinying Liu,Jiabao Zhang,Yue Zhang,Yan Wang,Mengke Wang,Ziwen Li,Guannan Wang,Xingguang Su

In this paper, we proposed a dual-signal fluorometric and colorimetric system based on silicon quantum dots (SiQDs) and 4-nitrophenol (4-NP) for pH and urease sensing. SiQDs with fluorescence emission of 460 nm were prepared via aqueous-phase synthesis. As the pH of the system gradually increased, the absorption band of 4-NP at 400 nm increased and a color reaction from colorless to yellow occurred. The absorption of 4-NP overlapped quiet well with the fluorescence excitation spectrum of SiQDs, which can effectively quench the fluorescence of SiQDs. Therefore, the change of fluorescence and absorption intensities could be used to quantify pH value. The fluorometric and colorimetric pH-sensing systems both exhibited a linear respond to pH ranging from 6.0 to 7.8 with an interval of 0.2 pH unit. Urease could specifically hydrolyze urea to generate carbon dioxide and ammonia, causing an obvious increase of the pH value. Thus, urease could also be detected quantitatively by the above dual-signal pH sensing system. The linear ranges of the fluorometric and colorimetric methods for urease detection were both 2–40 U L-1. The limits of detection were 1.67 and 1.07 U L-1, respectively. More importantly, this established dual-signal system has been successfully exploited in the detection of urease in real samples with satisfactory recoveries. Compared with other traditional single-signal assay strategies, the results obtained by dual-signal methods are more accurate and reliable.

Coiled-Coil Domain Containing 80 Suppresses Nonylphenol-Induced Colorectal Cancer Cell Proliferation by Inhibiting the Activation of ERK1/2

Wang Jing,Zhang Yuan-wei,Zhang Nian-jie,Yin Shuo,Ruan Du-ji,He Nian,Chen Xu,Yang Xue-feng

Recently, the effect of endocrine-disrupting chemicals on the cancer procession has been a concern. Nonylphenol (NP) is a common environmental estrogen that has been shown to enhance the proliferation of colorectal cancer (CRC) cells in our previous studies; however, the underlying mechanism remains unclear. In this study, we confirmed the increased concentration of NP in the serum of patients with CRC. RNA sequencing was used to explore the differentially expressed genes after NP exposure. We found 16 upregulated genes and 12 downregulated genes in COLO205 cells after NP treatment. Among these differentially expressed genes, we found that coiled-coil domain containing 80 (CCDC80) was downregulated by NP treatment and was associated with CRC progression. Further experiments revealed that the overexpression of CCDC80 significantly suppressed NP-induced cell proliferation and recovered the reduced cell apoptosis. Meanwhile, the overexpression of CCDC80 significantly inhibited the activation of ERK1/2 induced by NP treatment. ERK1/2 inhibitor (PD98059) treatment also suppressed NP-induced CRC cell growth, but the overexpression of CCDC80 did not enhance the effect of ERK1/2 inhibitor. Taken together, NP treatment significantly inhibited the expression of CCDC80, and the overexpression of CCDC80 suppressed NP-induced CRC cell growth by inhibiting the activation of ERK1/2. These results suggest that NP could induce CRC cell growth by influencing the expression of multiple genes. CCDC80 and ERK1/2 inhibitors may be suitable therapeutic targets in NP-related CRC progression.

Facile synthesis of Ag3PO4/PPy/PANI ternary composites for efficient catalytic reduction of 4-nitrophenol and 2-nitroaniline

Jinming Ma,Huizhen Deng,Zhe Zhang,Lexin Zhang,Zhihui Qin,Yaru Zhang,Lili Gao,Tifeng Jiao

In this study, a series of Ag 3 PO 4 /PPy/PANI ternary composite catalysts were fabricated by adjusting the mixed solution of pyrrole and aniline with different volume ratios of 4:1, 3:2, 1:1, 2:3, and 1:4, and combining with the in-situ synthesis method. The synthesized Ag 3 PO 4 /PPy/PANI nanoparticles were examined by XRD , SEM, TEM and EDX , Raman spectroscopy . When the ratio of pyrrole and aniline is 1:1, the polymerized PPy/PANI acted as the supporting matrix to effectively immobilize and prevent the aggregation of Ag 3 PO 4 nanoparticles. The catalytic performances of the Ag 3 PO 4 /PPy/PANI composites were confirmed for reduction of 2-nitroaniline (2-NA) and 4-nitrophenol (4-NP) in the presence of NaBH 4 at room temperature by UV–vis spectroscopy. Results showed that the catalytic reduction effect of the Ag 3 PO 4 /PPy/PANI (1:1) on 2-NA is obviously better than that on 4-NP, which followed the pseudo-first-order kinetic, and the corresponding rate constants are 0.0053 min −1 and 0.022 min −1 , respectively, indicating that it has potential application in wastewater treatment in industries.

Mussel chemistry inspired synthesis of Pd/SBA-15 for the efficient reduction of 4-nitrophenol

Xiao Jiang,Qing-Da An,Zuo-Yi Xia,Shang-Ru Zhai,L. Zhong-Cheng,Kai Wang

In this study, N-doped platelet-like metal-loaded Zr/SBA-15 was synthesized and employed for reducing 4-nitrophenol to remove this contaminant from water. Dopamine hydrochloride was used as a novel CN source for the modification of ZrSBA-15. The N doping process occurred readily at a low temperature due to the polymerization of dopamine, which could save energy and simplify the experimental fabrication of catalysts. In addition, polydopamine can immobilize Pd ions in a facile manner and the trapped Pd ions are reduced to Pd nanoparticles due to the reducibility of the polydopamine polymer. The utilization of dopamine allows the catalyst to be obtained in a facile and cost-effective synthetic process, while the production of the CN layer as well as the reduction and immobilization of the Pd ions can occur simultaneously. Characterization of the product showed that the catalyst had a platelet-like structure after decoration with elemental Zr, which enhanced the catalytic reaction compared with the natural fiber-like SBA-15. The optimal Pd loading capacity was determined as ~3.0 wt% and the materials obtained could reduce 4-nitrophenol to 4-aminophenol within 120 s with a conversion ratio above 90%.

A photo-switch for peroxydisulfate non-radical/radical activation over layered CuFe oxide: Rational degradation pathway choice for pollutants

Junqin Liu,Pingxiao Wu,ShanShan Yang,Saeed Rehman,Zubair Ahmed,Nengwu Zhu,Zhi Dang,Zehua Liu

This work presents a novel strategy for peroxydisulfate (PDS) activation under controlled non-radical/radical mechanism, which is based on a photo-switch over layered CuFe oxide (CFO). The non-radical mechanism is attained by CFO under dark environment, and the radical mechanism is achieved through the visible light irradiation. Electron paramagnetic resonance (EPR) and density functional theory (DFT) studies demonstrate the non-radical activation mechanism is conducted by the polarization effect of CFO to PDS molecule. The radical mechanism could be elucidated by the one-electron reduction of the PDS by excited electrons on conduction band of CFO. Products analyses based on HPLC-MS and Fukui functions suggest that the non-radical degradation pathway could decrease the generation of halide intermediates, whereas the radical pathway may not be observed with this property. Quantitative structure-activity relationships (QSARs) were established between the observed pseudo-first-order rates of various phenolic pollutants and the classical descriptors (i.e., Hammett constant, Pka, E HOMO and E LUMO ) in the non-radical and radical systems, respectively, to give instructions of pathway choice for different pollutants. Considering the non-radical/radical pathway both have their own unique strengths (e.g., non-radical pathway has high selectivity to pollutants and high utilization efficiency of oxidant, and radical pathway has considerable degradation rate and strong mineralization ability), these pathways should be chosen wisely for pollutant degradation according to reality conditions.

Accumulation and Depuration of Nonylphenol and Its Effect on the Expressions of Vitellogenin and Vitellogenin Receptor in Freshwater Prawn Macrobrachium rosenbergii

Guo Hui,Chen Luan-luan,Li Guang-li,Deng Si-ping,Zhu Chun-hua

Accumulation of nonylphenol (NP) in hepatopancreas, gonad, eyestalk, and muscle of freshwater prawn Macrobrachium rosenbergii following 72 h exposure to 100 µg/L NP, and depuration of NP in these tissues at 0.5–192 h post exposure were examined. We also examined the expressions of vitellogenin (Vg) and vitellogenin receptor (VgR) of prawn following 0–20 days exposure to 0, 1, 10, and 100 µg/L NP. NP accumulation in hepatopancreas and gonad with high concentration, and low concentration in muscle, but depurated faster in eyestalk and muscle. The expressions of vitellogenin (Vg) and vitellogenin receptor (VgR) increased directly with dose and time. In conclusion, NP accumulated significantly in gonad together with high Vg and VgR expressions, and depurated slow in hepatopancreas and gonad when prawns were removed back to control water. The induction of Vg and VgR under NP exposure might be a stress response in M. rosenbergii .

Mercapto-Functionalized Porous Organosilica Monoliths Loaded with Gold Nanoparticles for Catalytic Application

Hongwei Li,Junhui Pan,Chengtao Gao,Mengyu Ma,Liangyu Lu,Yuzhu Xiong,Fuping Dong

Porous organosilica monoliths have attracted much attention from both the academic and industrial fields due to their porous structure; excellent mechanical property and easily functionalized surface. A new mercapto-functionalized silicone monolith from a precursor mixture containing methyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane; and 3-mercaptopropyl(dimethoxy)methylsilane prepared via a two-step acid/base hydrolysis–polycondensation process was reported. Silane precursor ratios and surfactant type were varied to control the networks of porous monolithic gels. Gold nanoparticles were loaded onto the surface of the porous organosilica monolith (POM). Versatile characterization techniques were utilized to investigate the properties of the synthesized materials with and without gold nanoparticles. Scanning electron microscopy was used to investigate the morphology of the as-synthesized porous monolith materials. Fourier transform infrared spectroscopy was applied to confirm the surface chemistry.29Si nuclear magnetic resonance was used to investigate the hydrolysis and polycondensation of organosilane precursors. Transmission electron microscopy was carried out to prove the existence of well-dispersed gold nanoparticles on the porous materials. Ultraviolet–visible spectroscopy was utilized to evaluate the high catalytic performance of the as-synthesized Au/POM particlesKeywords:porous organosilica monolith;silicone-based materials;organic–inorganic hybrid materials;gold nanoparticles;sol-gel;catalyst

Ordered mesoporous silica cubic particles decorated with silver nanoparticles: a highly active and recyclable heterogeneous catalyst for the reduction of 4-nitrophenol

Hui-Tao Fan,Xue-Guo Liu,Xiao-Jing Xing,Bo Li,Kun Wang,Shu-Ting Chen,Zhou Wu,Dong-Fang Qiu

In this work, using a modified Stöber process, we synthesized ordered mesoporous silica cubic particles (OMS-C) and prepared a nanocatalyst (Ag–OMS-C) based on OMS-C with a high surface area via an in situ auto-reduction strategy. The as-prepared Ag–OMS-C nanocomposites demonstrated open mesopores (3.51 nm), a large specific surface area (540 m2 g−1) and a high pore volume (0.88 cm3 g−1). The catalytic reduction of 4-nitrophenol (4-NP) over the Ag–OMS-C nanocatalyst was almost complete within 150 s without stirring and the rate constant k (30 × 10−3 s−1) is much higher than those of other substrate-supported Ag nanocatalysts. Moreover, the Ag–OMS-C nanocomposites hold a stable catalytic efficiency over five reaction cycles. The results indicate that the Ag–OMS-C nanocatalyst exhibited high catalytic activity and good reusability toward the reduction of 4-NP, which might be attributed to the large specific surface area, the pore structure of the nanocatalyst, as well as the synergistic effect between OMS-C and AgNPs.

Assembly of graphene-coated nickel nanowires and their catalytic performance

Zhiqiang Xu,Mingwei Liang,Lijuan Sun,Kenan Xie,Li Liao