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Chen X.,Jimei University | Zhao L.,Jimei University | Tian X.,Jimei University | Lian S.,Jimei University | And 3 more authors.
Talanta | Year: 2014

A novel method for the determination of tetracyclines (TCs) using electrochemiluminescence (ECL) based on a Ru(bpy)3 2+-doped silica nanoparticles (RuSiNPs)/Nafion film modified electrode is presented in this paper. The RuSiNPs were prepared by a water-in-oil microemulsion method. The characterization results indicated that the thus-prepared RuSiNPs presented a uniform size of 45 nm and retained the original electrochemical properties of Ru(bpy)3 2+. Importantly, the ECL response on RuSiNPs/Nafion film modified electrode was greatly enhanced by TCs. Under the optimum conditions, the ECL intensity versus the concentration of TCs was found to be linear over the range of 1-100 μmol L-1 for tetracycline (TC), 0.1-100 μmol L-1 for oxytetracycline (OTC) and 1-100 μmol L-1 for chlortetracycline (CTC). The detection limits (S/N=3) were 0.23 μmol L-1 for TC, 0.10 μmol L-1 for OTC and 0.16 μmol L-1 for CTC. Moreover, due to the electrostatic interaction between Ru(bpy)3 2+ and silica matrix, the leaching of Ru(bpy)3 2+ was greatly reduced, therefore, the ECL sensor exhibited excellent repeatability and stability in the detection of TCs. Based on these investigations, the proposed ECL approach was successfully used to analyze the TCs content in drugs. © 2014 Elsevier B.V. Source


Zhou R.,Shenzhen University | Shi X.,Shenzhen University | Cai N.,Shenzhen University | Jiang Z.,Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering | Xu X.,Shenzhen University
Journal of Agricultural and Food Chemistry | Year: 2015

Alginate has notably diverse pharmacological activities. The present study investigated the anti-inflammatory activity of the guluronate oligosaccharides prepared by oxidative degradation (GOS-OD) from alginate. GOS-OD significantly attenuated the production of nitric oxide (NO), prostaglandin E2 (PGE2), and reactive oxygen species (ROS), the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, and the secretion of pro-inflammatory cytokines in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells. Moreover, GOS-OD potently decreased the binding of LPS to the cell surface and LPS-induced Toll-like receptor 4 (TLR4) and cluster of differentiation (CD) 14 expression. Additionally, GOS-OD could remarkably inhibit the LPS-induced activation of nuclear factor (NF)-κB and mitogen-activated protein (MAP) kinase pathways in RAW 264.7 cells. These results indicate that GOS-OD may reduce the LPS-stimulated inflammatory responses through blocking the activation of NF-κB and MAP kinases, suggesting that GOS-OD may be considered as a potential nutraceutical for inflammation. © 2014 American Chemical Society. Source


Gao Z.-H.,Jimei University | Lin Z.-Z.,Jimei University | Lin Z.-Z.,Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering | Chen X.-M.,Jimei University | And 3 more authors.
Analytical Methods | Year: 2016

A facile and green hydrothermal method was developed for the preparation of highly luminescent nitrogen-doped carbon dots (NCDs) by using anhydrous citric acid and urea as the carbon source and nitrogen source, respectively. The NCDs show good water-solubility and exhibit excitation-independent fluorescence behaviors at excitations of 300-390 nm with a quantum yield of 42.5% at a λem of 440 nm. Based on the fluorescence quenching strategy, the NCDs were successfully applied to the measurement of Hg2+ in tap and lake water samples with high sensitivity and excellent selectivity. The detection limit was 7.3 nmol L-1 (3σ, n = 9), indicating its potential applications for the detection of trace Hg2+ in water samples. © The Royal Society of Chemistry 2016. Source


An D.,Jimei University | Li Y.,Jimei University | Jiang Z.,Jimei University | Jiang Z.,Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering | Wang L.,Jimei University
Journal of Chinese Institute of Food Science and Technology | Year: 2014

Based on biogenic amine have significant sensitization effect on the electrochemical luminescence signal of [Ru (bpy)3 2+], a CE-ECL systerm for the electrochemical luminescence is established. In this paper, on the basis of the electrochemical luminescence of [Ru(bpy)3 2+] signal, focuses on testing conditions in the detection cell. The results indicate that under the optimized conditions, detection potential at 1.15 V, 5 mmol/L [Ru(bpy)3 2+](pH=7.00), sample injection at 13kV × 10s, 50 mmol/L of phosphate buffer at pH 7.00. Under the optimized conditions, the ECL intensity was linear with concentration of histamine dihydrochloride in the range of 1~100 μmol/L. The linear equation for I=149.48c + 45.141, correlation coefficient r=0.9961 (n=5) with detection limit (S/N=3) of 0.496 μmol/L. Spermidine, under its optimal conditions, the ECL intensity was linear with concentration of histamine dihydrochloride in the range of 1.5~7.5 μmol/L. The linear equation for I=6426.7c + 4.72, correlation coefficient r=0.9978(n=5) with detection limit (S/N=3) of 0.6 μmol/L. Optimal conditions for sample of histamine and spermine were measured, are not detected in the samples of histamine. The method used to determinate spermidine in the green moth samples, the relative standard deviation (RSD) of peak height and migration time were 0.48% and 1.67%, recovery is 115.14%~118.02%. In the clam samples, the relative standard deviation (RSD) of peak height and migration time were 0.48% and 1.67%, recovery is 108.82%~112.34%. In the sea seeds samples, the relative standard deviation (RSD) of peak height and migration time were 2.03% and 1.82%, recovery is 107.26%~119.50%. ©, 2014, Chinese Institute of Food Science and Technology. All right reserved. Source


Gao Z.-H.,Jimei University | Lin Z.-Z.,Jimei University | Lin Z.-Z.,Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering | Chen X.-M.,Jimei University | And 4 more authors.
Sensors and Actuators, B: Chemical | Year: 2016

A facile and green method was developed to prepare amino-functionalized fluorescent carbon dots (FCDs) for the detection of Hg2+ in aqueous solution. The water-soluble FCDs with the diameter around 3-5 nm were synthesized using anhydrous citric acid as carbon sources, NaBH4 as reducing agent and ammonia as passivation agent. The as-prepared FCDs exhibit blue emission at 440 nm with quantum yield as high as 36% using quinine sulfate as reference. The fluorescence intensity of the FCDs can be quantitatively quenched by Hg2+ with high sensitivity and selectivity. The FCDs were successfully applied to the measurement of Hg2+ in water samples with a detection limit of 20 nmol L-1 (3σ, n = 9), indicating that the amino-functionalized FCDs probe can be potentially applied to the detection of trace Hg2+ in water samples. © 2015 Elsevier B.V. All rights reserved. Source

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