查找使用阿拉丁产品的科研文献

Hierarchical metal-dielectric-metal nanostructures as SERS sensors for sensitive detection of polycyclic aromatic hydrocarbons

Shiqiang Wang,Huiyun Jiang,Junjie Feng,Yan Jin,Fei An,Liang Zhu,Anshan Xiao

Due to the wide variety, inaccessible self-degradation, high mutagenicity and carcinogenicity of polycyclic aromatic hydrocarbons (PAHs), it still remains challenging to efficiently identify them, especially in real environment. Herein, we develop a bottom-up self-assembly strategy to construct a sandwich-like hierarchical metal-dielectric-metal system composed of mercaptan-modified Au nanospheres-graphene oxide (GO)-Ag nanowires as surface-enhanced Raman spectroscopy (SERS) sensors for sensitive detection of PAHs. The synergistic integration of metallic layers and the organic mercaptan and GO layer not only provides localized enhanced electromagnetic field region which is induced by the nanogap between the top Au nanospheres and the bottom Ag nanowires, but also effectively traps PAHs in the middle layer through hydrophobic interaction of mercaptan and π-π stacking interaction of GO. By rationally optimizing the SERS substrates, the lowest detection concentrations of pyrene, anthracene, phenanthrene and benzo[a]pyrene could be reached, respectively, at 10 −8  M, 10 −8  M, 10 −8  M and 10 −7  M. The hierarchical system shows excellent uniformity, reproducibility and is able to identify various types of PAHs in multi-component mixtures as well as in real water environment. This strategy can provide a general platform to identify hazardous pollutants that are hydrophobic or contain benzene rings, such as pesticides, dyes and polychlorinated biphenyls.

Responses of a polycyclic aromatic hydrocarbon-degrading bacterium, Paraburkholderia fungorum JT-M8, to Cd (II) under P-limited oligotrophic conditions

Jinghua Li,Yiwen Ou,Lijuan Wang,Yue Zheng,Weiyun Xu,Jianbiao Peng,Xin Zhang,Zhiguo Cao,Junpei Ye

For the bioremediation of mixed-contamination sites, studies on polycyclic aromatic hydrocarbon (PAH) degradation or Cd (II) tolerance in bacteria are commonly implemented in nutrient-rich media. In contrast, in the field, inocula usually encounter harsh oligotrophic habitats. In this study, the environmental strain Paraburkholderia fungorum JT-M8 was used to explore the overlooked Cd (II) defense mechanism during PAH dissipation under P-limited oligotrophic condition. The results showed that the growth and PAH degradation ability of JT-M8 under Cd (II) stress were correlated with phosphate contents and exhibited self-regulating properties. Phosphates mainly affected the Cd (II) content in solution, while the cellular distribution of Cd (II) depended on Cd (II) levels; Cd (II) was mainly located in the cytoplasm when exposed to less Cd (II), and vice versa. The unique Cd (II) detoxification pathways could be classified into three aspects: (i) Cd (II) ionic equilibrium and dose–response effects regulated by environmental matrices (phosphate contents); (ii) bacterial physiological self-regulation, e.g., cell surface-binding, protein secretion and active transport systems; and (iii) specific adaptive responses (flagellum aggregation). This study emphasizes the importance of considering culture conditions when assessing the metal tolerance and provides new insight into the bacterial detoxification process of complex PAH-Cd (II) pollutants.

Vitamin D3 mediated peptides-calcium chelate self-assembly: Fabrication, stability and improvement on cellular calcium transport

Zheng Fang,Xiaoping Wu,Fangfang Wang,Fan Li,Xixi Cai,Vincent Guyonnet,Shaoyun Wang

A self-assembled peptides-calcium-Vitamin D 3 ternary delivery system (CSPH-Ca-VD 3 ) was prepared to investigate the promotion of cellular calcium transport. The constructed CSPH-Ca-VD 3 nanocomplex exhibited a spherical structure with a size of 135.2 ± 10.2 nm. Based on the thermodynamic calculation of fluorescent spectra, hydrophobic interaction was shown as the major driving force for this nanocomplex structure. CSPH-Ca-VD 3 nanocomplex possessed excellent stability during simulated gastrointestinal digestion, contributing to the prevention of acid degradation of VD 3 and the enhancement of calcium solubility. Furthermore, the calcium transport efficiency in the form of CSPH-Ca-VD 3 (4 mg/mL) across a Caco-2 cells monolayer was significantly increased 2.3-fold compared to that of free Ca 2+ , mainly attributed to the upregulation in the presence of CSPH-Ca-VD 3 of TRPV6, calbindin D9k and PMCA1b expression in Caco-2 cells. The present study provided a basis for developing a novel delivery system of peptides-calcium chelate with the dual effects of VD 3 protection and calcium uptake promotion.

Pioglitazone-Loaded Cartilage-Targeted Nanomicelles (Pio@C-HA-DOs) for Osteoarthritis Treatment

Junyan Chen,Wuyan Xu,Tianming Dai,Songsong Jiao,Xiang Xue,Jiayang Jiang,Siming Li,Qingqi Meng

Highly graphitized porous carbon/reduced graphene oxide for ultrahigh enrichment and ultrasensitive determination of polycyclic aromatic hydrocarbons

Yaming Sun,Wenjie Sun,Junnan Li,Tao Zhang,Wenjie Zhao,Guoqiang Xiang,Tiantian Yang,Lijun He

There is an urgent need to develop efficient and reliable coating materials for solid phase microextraction (SPME), in order to quantify and monitor pollutants in environmental waters. Herein, a highly graphitized porous carbon/reduced graphene oxide (PC/rGO) was successfully synthesized by pyrolysis of metal organic framework / graphene oxide precursors, and used as a SPME coating for ultrahigh enrichment of polycyclic aromatic hydrocarbons (PAHs) from water. The as-prepared PC/rGO exhibited high degree of graphitization , abundant number of micro/mesopores along with exceptional thermal stability, making it an ideal SPME coating material. The PC/rGO fiber offered an ultrahigh enrichment factor for PAHs (up to 126057), which could be attributed to the multiple interactions between the PC/rGO and PAHs, including hydrophobic and π - π interactions, partitioning, and mesopore filling effect. In the analysis of PAHs, the PC/rGO fiber showed a wide linearity (0.007–100 ng mL −1 ), low limits of detection (0.0005–0.005 ng mL −1 ), and good repeatability (RSDs <10.1%, n  = 5) under optimized conditions. The established method was applicable for ultrasensitive determination of PAHs in different environmental waters and showed satisfactory recoveries. This study provides a novel way for constructing thermally stable SPME coating having efficient extraction performance.

New insights into thermal desorption remediation of pyrene-contaminated soil based on an optimized numerical model

Shuai Zhang,Jiating Zhao,Lizhong Zhu

Thermal desorption (TD) is known as an effective technique to remediate PAHs-contaminated sites. However, effectively removing PAHs using TD while saving time, and energy, and minimizing soil damage remains a challenge. In this study, we examined the combined effects of various factors on the removal efficiency of pyrene (PYR) by TD and developed an optimal numerical model based on conducting a series of soil experiments. The results showed that temperature (T) and time (t) promoted the desorption of PYR, while water ( S w ) and organic matter ( f om ) were just the opposite. Besides, water and organic matter had a synergistic effect proportionally. It was found that adjusting the soil-water ratio (which can be controlled by organic matter) maximized the desorption rate of PYR. An ideal S w / f om 1.56 and a minimized recommended temperature (173 °C) were proposed based on the model. Finally, the efficacy of the optimized scheme was validated in real-world site soil. These findings not only mechanistically revealed the desorption behavior of PYR under the influence of various factors, but also provided an optimized scheme for efficiently removing PAHs using TD, thereby accelerating the remediation process and reducing energy consumption. The modeling ideas and conclusions obtained may be applicable to other PAHs, guiding the effective remediation of PAHs-polluted sites.

Temperature-triggered boron-doped carbon nanoparticles-labeled polyethylene terephthalate with dual emission for double-level fluorescence anti-counterfeiting

Jiaqi Zhang,Zelin Zhang,Haohao Li,Yang Xu

The sustainable applications of plastics are extremely challenging in the field of environment. Here, a facile synthesis of temperature-triggered fluorescence platform composed of boron-doped carbon nanoparticles (BCNPs) and polyethylene terephthalate (PET) was proposed as a convenient way to reuse PET plastic products. Notably, the fluorescence of this platform was tuned by incubation temperature and suitable for double-level anti-counterfeiting by utilizing significant difference of fluorescence emission upon 365 and 254 nm excitations, respectively. With a long-term heating regulation, multi-fluorescence emissions could be obtained as fluorescent codes. The fluorescence was assigned that blue emission originated from PET state and red emission derived from surface state of BCNPs. The red emission was enhanced with the increase of temperature, which was the formation mechanism of varied fluorescence. The multi-color emission performance was also validated using slices cut from PET bottle to demonstrate practicability of the platform. The adjustable fluorescence performance made the platform had good anti-counterfeiting ability, which provided a new way for the reuse of PET.

Detoxification of coal-tar pitch by alkylation method and toxicity evaluation by chemical index, fumes and water-soluble substances

Wen-shuo Zhang,Li-peng Tan,Jun Shen,Yu-gao Wang,Gang Liu,Qing-bai Xu

Coal-tar pitch (CTP) output in China has consistently exceeded 7 million tons annually since 2011. CTP contains 16 toxic polycyclic aromatic hydrocarbons (PAHs) that are preferentially monitored by the American Environmental Protection Agency (EPA). As a result, the widespread and extensive use of CTP is restricted. Consequently, finding ways to reduce the toxicity of CTP has become an urgent concern. In the paper, the reaction conditions were optimized using model compounds (naphthalene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, benzo [a]pyrene) of CTP. Subsequently, the CTP was modified through alkylation reaction using 1-dodecene, and the detoxification effect was evaluated based on chemical index, fumes, and water-soluble substances. The total content of 16 toxic PAHs in the modified CTP (MCTP) decreased by 75.56% compared to the original CTP. The toxicity equivalent quotient (TEQ) of the MCTP was reduced by more than 65% according to different environmental standards. The content of the 16 PAHs detected in MCTP fumes released at 140 °C decreased by 80.89%, while in water-soluble substances it decreased by 64.04% and 76.67% at 30 °C and 60 °C, respectively. These results strongly indicate the effectiveness of the alkylation method in reducing the toxicity of CTP. However, in order to develop more environmentally-friendly materials, it is necessary to explore more efficient catalysts and cheaper modifiers, which will be the focus of our future research. Novelty Statement This study investigated the toxicity inhibition of CTP to reduce the content of PAHs by alkylation method. The modification process was analyzed using model compounds to understand the potential reaction pathways. The objective of toxicity inhibition was achieved by creating low-toxicity and long-chain alkyl substitutes. Additionally, the toxicity of CTP and MCTP was assessed by introducing fumes and water-soluble substances.

Self-Assembled Amphiphilic Camptothecin Nanoparticles with Glutathione-Responsive and Tumor-Targeting Ability for Enhanced Colorectal Cancer Therapy

XiaoJie Song,Kang-Li Lan,Yi-Fei Xue,Hong-Min Liu,Qi-Yan Lv,Zhen Zhao,Hui-Fang Cui

Camptothecin (CPT) is impeded by low solubility, non-tumor-targeting ability, and fast blood clearance. Self-assembly of hydrophobic drugs into nanostructures, especially nanoparticles (NPs), can improve their anti-cancer effects. In this study, arginine-glycine-aspartic acid (RGD), a hydrophilic and tumor-targeting peptide, is conjugated with CPT through a glutathione-cleavable disulfide bond. The synthesized amphiphilic molecule CPT-ss-RGD self-assembled into stable NPs in an aqueous solution with diameters of ≈86nm. They exhibited low critical aggregation concentrations, good stability, and glutathione responsiveness. They can be specifically taken up by CRC cells through RGD integrin-mediated uptake, and exhibit high toxicity to CRC cells and multicellular tumor spheroids. As expected, CPT-ss-RGD NPs prolonged the blood circulation time and enhanced the tumor accumulation of CPT, exhibiting excellent anti-tumor growth ability and few side effects. Thus, CPT-ss-RGD NPs have great clinical translational potential for CRC therapy. The successful self-assembly of the CPT-ss-RGD NPs provides a new method for the self-delivery of hydrophobic therapeutics in vivo.

Generation and application of a novel transgenic zebrafish line Tg(GAcyp1a:eGFP/Luc) as an in vivo assay to sensitive and specific monitoring of DLCs in the environment

Shaolin Xie,Bing Yang,Siying Li,Liangjun Ge,Min Li,Qingshi Chen,Xian Qing,Jixing Zou

CYP1A is the most commonly used biomarker and transgenic fish which carrying a cyp1a promoter to drive a reporter gene can be used as reliable way to monitor dioxin/dioxin-like compounds (DLCs) in the environment. Here, we cloned the cyp1a promoter of Gambusia affinis and this promoter showed stronger transcriptional activity than that of zebrafish. Then, a Tg(GAcyp1a:eGFP/Luc) transgenic zebrafish line was first constructed with the G. affinis cyp1a promoter driving eGFP expression using meganuclease I-SceI mediated transgenesis technology. The Tg(GAcyp1a:eGFP/Luc) larvae at 72 h post-fertilization (hpf) were tested by exposing to TCDD for 72 h, and induced GFP was mainly expressed in the liver with low background. The Tg(GAcyp1a:eGFP/Luc) zebrafish showed high sensitivity (limit of detection of 0.322 ng/L TCDD and 0.7 TEQ-ng/L PCDD/Fs) and specificity (insensitive to responses to PAHs and PCBs). In addition, the transgenic line showed a low detection concentration of the DLCs contaminated environmental samples (as low as 1.8 TEQ-ng/L), and the eGFP fluorescence intensity and the chemical-TEQ values were closely correlated. In conclusion, a sensitively and specifically transgenic zebrafish line was established to convenient and effective to detect DLCs in the environment.

Application of temperature-sensitive hyperbranched polysiloxanes for the determination of polycyclic aromatic hydrocarbons in foodstuffs

Xiaomei Chen,Liulin Wei,Qian Liu,Xueyun Gao,Jingchan Zhao

In the present study, a novel temperature-sensitive hyperbranched polysiloxane dispersive liquid–liquid microextraction combined with high-performance liquid chromatography method (TS-HBPSi-DLLME-HPLC-UV) has been developed for the determination of five polycyclic aromatic hydrocarbons (PAHs) in instant noodles, in which temperature-sensitive hyperbranched polysiloxane (p(Ph-HBPSi-co-NIPAM)) was used as the extraction solvent. The method adsorbs the target analytes based on π-π and hydrophobic interaction between p(Ph-HBPSi-co-NIPAM) and PAHs, and then separates the polymer with the adsorbed target analytes from the solution by a phase transition. Microextraction parameters of the method including polymer ratio, type and concentration of salt, pH, extraction time and volume of acetonitrile were examined in detail and optimized. At the optimum conditions, the established method showed good linearity (R 2  ≥ 0.9971) with satisfactory limits of detection (0.089–0.16 ng mL −1 ) and limits of quantitation (0.27–0.48 ng mL −1 ). The values for intra-day and inter-day precisions were lower than 3.2% and 4.4%, respectively. Enrichment factors (EFs) and extraction recoveries (ERs) ranged from 62 to 70 and 75 to 85%, respectively. Finally, the proposed microextraction technique was validated by analyte addition and recovery studies, and applied to the determination of five PAHs in instant noodles, demonstrating that temperature-sensitive hyperbranched polymers have great potential for application in sample pretreatment techniques.

Chemometrics-assisted excitation-emission matrix fluorescence spectroscopy for real-time migration monitoring of multiple polycyclic aromatic hydrocarbons from plastic products to food simulants

Kun Huang,Hai-Long Wu,Tong Wang,Ming-Yue Dong,Xiao-Qin Yan,Ru-Qin Yu

Polycyclic aromatic hydrocarbons (PAHs), as a class of organic pollutants that have attracted much attention, are likely to be formed with the production and processing of plastic products, and they may migrate from contaminated plastic products to food, causing the risk of poisoning or cancer. In this study, migration tests were carried out on disposable plastic products for food contact, and a novel strategy that combines excitation-emission matrix (EEM) fluorescence spectroscopy with the advanced second-order calibration method based on the three-direction resection alternating trilinear decomposition (TDR-ATLD) algorithm was used to monitor the migration of three PAHs anthracene (ANT), pyrene (PYR), and phenanthrene (PHE) from the plastic products to food simulants in real-time. With the “second-order advantage”, even if the fluorescence spectra of the target analytes overlapped seriously, and other unknown substances migrated from the plastic products to food simulants, accurate qualitative and quantitative results were still obtained by the proposed method. In the static system, the coefficient of determination ( R 2 ) of the three PAHs within the calibration range were all greater than 0.99, and the average spiked recoveries were 99.5-107.1%, with the standard deviation lower than 8.9%. The figures of merit (FOMs) and intra- or inter-day precision also showed good feasibility and reliability of the method. In the simulation study of the migration kinetic process, three PAHs can be quantified in real-time in complex matrix, then the related migration equations were established. The results indicate that the proposed method can be used for real-time migration quantitative monitoring of PAHs, providing a potential and available method for the study of the migration kinetics of hazardous substances from food contact materials to food or food simulants.