Time filter

Source Type

Xu Q.,Nanjing Southeast University | Xu Q.,Suzhou Key Laboratory of Environment and Biosafety | Wang M.,Nanjing Southeast University | Wang M.,Suzhou Key Laboratory of Environment and Biosafety | And 4 more authors.
Analyst | Year: 2011

A simple, rapid and sensitive method for the determination of diethylstilbestrol (DES), dienestrol (DE) and hexestrol (HEX) was developed by using the Nylon 6 nanofibers mat-based solid-phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS). These estrogens were separated within 8 min by LC using an ODS column and methanol/water (80/20, v/v) at a flow rate of 1.0 mL min -1. Electrospray ionization conditions in the negative ion mode were optimized for MS detection of the estrogens. Under the optimum SPE conditions, all target analytes in 50 mL environmental water samples can be completely extracted by 1.5 mg Nylon 6 nanofibers mat at flow rate of 3.0 mL min -1 and easily eluted by passage of 500 μL mobile phase. By using the novel SPE-LC/MS method, good linearity of the calibration curve (r 2 ≥ 0.9992) was obtained in the concentration range from 0.10 ng L -1 to 1.0 mg L -1 (except for DE which was 0.20 ng L -1 to 1.0 mg L -1) for all analytes examined. The limits of detection (S/N = 3) of the three estrogens ranged from 0.05 ng L -1 to 0.10 ng L -1. This method was applied successfully to the analysis of environmental water samples without any other pretreatment and interference peaks. Several water samples were collected from Jinchuan River and Xuanwu Lake, and in Jinchuan River water DES was detected at 0.13 ng L -1. The recoveries of estrogens spiked into tap water were above 98.2%, and the relative standard deviations were below 4.78%. © 2011 The Royal Society of Chemistry.


Lin X.,Nanjing Southeast University | Lin X.,Suzhou Key Laboratory of Environment and Biosafety | Rong F.,Suzhou Key Laboratory of Environment and Biosafety | Ji X.,Nanjing Southeast University | And 3 more authors.
Microporous and Mesoporous Materials | Year: 2011

A visible-light-active C-doped mesoporous TiO2 film was prepared by sol-gel process combined with hydrothermal treatment. Glucose was used as carbon source and structure-directing agent. The structure and physicochemical properties of the film were characterized by X-ray diffraction (XRD), N 2 adsorption-desorption isotherms, scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectrum (DRS) and photoluminescence (PL). The results indicated that oxygen sites in the TiO 2 lattice were substituted by carbon atoms and an O-Ti-C bond was formed. The C-doped mesoporous TiO2 film had a high surface area of 283 m2 g-1. The film was about 10 μm thick and was composed of anatase TiO2 particles. The prepared C-doped TiO 2 film exhibited excellent photocatalytic activity in the degradation of dye Reactive Brilliant Red X-3B (C.I. reactive red 2) under UV and visible light irradiation compared with that of the smooth TiO2 film and P25 film. The recycle ability of the C-doped mesoporous TiO2 film was also investigated. The degradation ratio which was still higher than 87% after 5 cycles, decreased by 3% compared to the first cycle. © 2010 Elsevier Inc.


Zhang Z.,Nanjing Southeast University | Zhang Z.,Suzhou Key Laboratory of Environment and Biosafety | Xie Y.,Nanjing Southeast University | Liu Z.,Nanjing Southeast University | And 6 more authors.
Journal of Electroanalytical Chemistry | Year: 2011

Highly ordered TiO2 nanotube array with inner diameter of 120 nm was formed by anodizing titanium foils and was further modified for enzyme immobilization and biosensing. AuNPs sized in 8-12 nm were uniformly electrodeposited on TiO2 nanotube arrays by pulsed method. Glucose oxidase (GOD) was covalently immobilized on the surface of gold nanoparticles (AuNPs) modified TiO2 nanotube array electrode for the first time. Results demonstrate that the modified TiO2 nanotube array electrode exhibits good electrocatalytic performance and high sensitivity without any electron mediator. The covalently fabricated glucose biosensor shows higher immobilized ratio of GOD, good reproducibility and stability. These indicate AuNPs modified TiO2 nanotube array is an attractive material for using in the fabrication of biosensors because of its excellent biocompatibility, high specific surface area, unique nanostructure, and effective immobilization of biomolecules. This facile modification approach could be extended to prepare various TiO2 nanotube array based biosensors. © 2010 Elsevier B.V. All rights reserved.


Rong F.,Nanjing Southeast University | Rong F.,Suzhou Key Laboratory of Environment and Biosafety | Li P.,Beihang University
High Performance Polymers | Year: 2011

The interactions between template and functional monomers of molecularly imprinted polymers (MIPs) were studied by ultraviolet and infrared spectral analysis and computer simulation, with S-naproxen as template molecule and methacrylic acid (MAA), acrylamide (AM) and 4-vinyl pyridine (4-VP) as functional monomers, respectively. Then, the S-naproxen imprinted polymers made from three functional monomers were prepared, respectively, and the binding parameters and chiral separation performance of the synthesized MIPs were investigated by Scatchard analysis and thin layer chromatography using MIPs as chiral stationary phase. The results showed that the MIP based on 4-VP possessed the highest imprinting effect while the MIP based on MAA was the lowest, which correlated positively with the interaction strength between template molecule and three monomers. The results of theoretical and experimental studies of S-naproxen imprinted polymers suggested that using spectral analysis and computer aided prediction could promote the synthetic strategy for researching more efficient MIPs. © SAGE Publications 2011.


Rong F.,Nanjing Southeast University | Rong F.,Suzhou Key Laboratory of Environment and Biosafety | Li P.,Beihang University
Advanced Materials Research | Year: 2012

Molecularly imprinted polymers (MIPs) of L-phenylalanine ethyl ester were synthesized in this study. Then, the prepared MIPs were packed in a stainless column and evaluated as the chiral stationary phases of high performance liquid chromatography (HPLC). The MIPs exhibited a considerable capability of chiral separation between template molecule and its enantiomer with the separation factor of 1.69. Furthermore, the weakest interaction model was introduced to study the chiral recognition mechanism of MIPs. The results suggested that the weakest interaction between the template molecule and the imprinted cavity played crucial role in chiral separation, and the molecular tension should be taken into consideration during the separation procedure. The separation factor of 2.07 was calculated by the theoretical model, which was very close to the value obtained from chromatographic experiment.


Zhao Y.,Nanjing Southeast University | Zhao X.,Nanjing Southeast University | Tang B.,Nanjing Southeast University | Xu W.,Nanjing Southeast University | And 2 more authors.
Langmuir | Year: 2010

We present a new method to prepare inverse opaline photonic beads with good spherical shape and superior optical performance by simply introducing an interfacial tension system into a template replication method. When the scaffolds of these beads were composed of poly(ethylene glycol) diacrylate hydrogel, they could provide a homogeneous water surrounding, which remedied many shortcomings of biomolecular microcarriers introduced by the presence of the solid surface of them. The suspension array, which used these macroporous hydrogel photonic beads as coding elements, showed obvious advantages in multiplexed capability, rapid biomolecular screening (within 12 min), and highly sensitive detection (with limit of detection of ∼10-12 M). © 2010 American Chemical Society.


Yin T.,Nanjing Southeast University | Lin Z.,Nanjing Southeast University | Su L.,Nanjing Southeast University | Yuan C.,Nanjing Southeast University | And 2 more authors.
ACS Applied Materials and Interfaces | Year: 2015

A unique vertically oriented TiO2 nanosheets (TiO2-NSs) layer was synthesized in situ on the surface of a carbon paper (CP) electrode via hydrothermal synthesis upon addition of a suitable amount of activated carbon powders in a reactor. Field emission scanning electron microscopy images showed that the nanosheets were about 2 μM in length, 200-600 nm in width and 15 nm in thickness. X-ray diffraction and Raman patterns verified TiO2-NSs crystallized in the anatase phase. The electrochemical activities of CP and TiO2-NSs/CP electrode have been investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The maximum power output density of a mixed consortia inoculated microbial fuel cell was increased by 63% upon using TiO2-NSs/CP as a bioanode compared with that using bare CP as a bioanode. The performance improvement could be ascribed to unique 3D open porous interface made of vertically oriented TiO2-NSs, which provides good biocompatibility, favorable mass transport process, large surface areas for adhension of bacteria and direct pathways for electron movement to the electrode. © 2014 American Chemical Society.


Deng J.,Nanjing Southeast University | Kang X.,Nanjing Southeast University | Kang X.,Suzhou Key Laboratory of Environment and Biosafety | Chen L.,Nanjing Southeast University | And 4 more authors.
Journal of Hazardous Materials | Year: 2011

An electrospun nanofiber was utilized as a sorbent in packed fiber solid phase extraction (PFSPE) for selective separation and preconcentration of lead (II). The nanofiber had a polystyrene (PS) backbone, which was functionalized with dithizone (DZ) by co-electrospinning of a PS solution containing DZ. The nanofiber exhibited its performance in a cartridge prepared by packing 5mg of nanofiber. The nanofiber was characterized by a scanning electron microscope and IR spectra. The diameter of the nanofiber was less than 400nm. After being activated by 2.0molL -1 NaOH aqueous solution, the nanofiber quantitatively sorbed lead (II) at pH 8.5, and the metal ion could be desorbed from it by three times of elution with a small volume of 0.1molL -1 HNO 3 aqueous solution. The breakthrough capacity was 16μgmg -1. The nanofiber could be used for concentration of lead (II) from water and other aqueous media, such as plasma with stable recovery in a simple and convenient manner. © 2011 Elsevier B.V.


Lin X.,Nanjing Southeast University | Lin X.,Suzhou Key Laboratory of Environment and Biosafety | Rong F.,Suzhou Key Laboratory of Environment and Biosafety | Fu D.,Nanjing Southeast University | And 2 more authors.
Powder Technology | Year: 2012

F-doped TiO 2 loaded with Ag (Ag/F-TiO 2) was prepared by sol-gel process combined with photoreduction method. The physical and chemical properties of the prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM), UV-vis diffuse reflectance spectroscopy (DRS), N 2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL). XPS analysis indicated that Ag species existed as Ag 0 in the structure of Ag/F-TiO 2 samples. UV-vis diffuse reflectance spectra showed that the light absorption of Ag/F-TiO 2 in the visible region had a significant enhancement compared with the F-doped TiO 2 (F-TiO 2). PL analysis indicated that the electron-hole recombination rate had been effectively inhibited when Ag loaded on the surface of F-TiO 2. The photocatalytic activities of the samples were evaluated by phenol and X-3B (Reactive Brilliant Red dye, C.I. reactive red 2) degradation under UV light irradiation and visible light (λ>420nm) irradiation, respectively. Compared with F-TiO 2, the sample of 0.50Ag/F-TiO 2 showed the highest photocatalytic activity under both UV and visible light irradiation. The interaction between F species and metallic Ag in the Ag/F-TiO 2 samples was responsible for improving the photocatalytic activity. © 2011 Elsevier B.V.


Xu S.,Nanjing Southeast University | Xu Q.,Nanjing Southeast University | Xu Q.,Suzhou Key Laboratory of Environment and Biosafety | Zhou J.,Nanjing Southeast University | And 3 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2013

For the purpose of achieving targeted chemotherapy of pancreatic cancer, we prepared core-shell nanoparticles by coaxial electrospray technology, with folate-chitosan as the polymeric coating material and gemcitabine as the encapsulated drug. The effects of various solution properties and processing parameters on nanoparticles formation were investigated. By optimizing the electrospray parameters, the diameter of the core-shell nanoparticles was in the range of 200∼300 nm with drug loading and encapsulation efficiency of 3.91±0.12% and 85.37±4.9%. The drug release kinetics revealed a controlled initial burst release followed by a sustained release over a period of 72 h at pH 7.4 and pH 5.0, and at pH 5.0 the drug released more quickly. Moreover, the cellular uptake experiment confirmed that the folate conjugated core-shell nanoparticles had high pancreatic cancer (BXPC3) cells uptake efficiency. And the cell cytotoxicity test displayed that they had remarkable cytotoxicity towards BXPC3 cells. This study indicates that coaxial electrospray is a facile technique in producing core-shell nanoparticles encapsulating hydrophilic small molecule drugs, and clearly infers that the folate conjugated core-shell nanoparticles is very much effective to use as a pancreatic tumor-targeted delivery carrier for anticancer drugs. Copyright © 2013 American Scientific Publishers All rights reserved.

Loading Suzhou Key Laboratory of Environment and Biosafety collaborators
Loading Suzhou Key Laboratory of Environment and Biosafety collaborators