Cong Kong

Chitosan-based adsorption and freeze deproteinization: Improved extraction and purification of synthetic colorants from protein-rich food samples

A freeze method for deproteinization coupling with the chitosan purification process was developed for the determination of 8 synthetic food colorants in protein-rich samples. The solvents for extraction and different methods for deproteinization were examined and selected. Chitosan was employed for the purification after deproteinization, and further compared with the traditional polyamine purification method. Determination of the purified extract was conducted through the separation using high performance liquid chromatography and detection by multi-wavelength mode. Under the optimum conditions, the method showed good linearity between 0.6 and 10mg/kg, for the 8 synthetic colorants, and the limit of detection was between 0.1 and 0.4 mg/kg as was defined when the ratio of signal to noise was three. The recoveries of the spiked samples were found to be between 83% and 91%. The intra-day precision and inter-day precision was estimated to be 3-10% and 6-12%, respectively. The developed method could be applied to deproteinization and clean-up for pretreatment of protein-rich samples.

Highly sensitive “turn-on” fluorescence probe for the detection of sparfloxacin in human serum using silica-functionalized CdTe quantum dots

In this study, an environment-friendly hydrothermal synthesis of hydrophilic silica-functionalized CdTe quantum dots (SQDs) has been developed by treatment of tetraethyl orthosilicate (TEOS) in the presence of CdTe QDs. The proposed SQDs show favorable photoluminescence (PL) at the peak wavelength of 620 nm with a quantum yield of approximately 32%, and exhibit excellent selectivity and sensitivity toward sparfloxacin (SPFX) in the range from 0.05 × 10−6 to 200 × 10−6 mol L−1. The detection limit of SPFX is as low as 0.035 × 10−6 mol L−1. The results show that the remarkably enhanced PL intensity of SQDs can be attributed to the hydrogen-bond interactions between the SQDs and SPFX. Furthermore, the amount of SPFX in the human serum samples detected by the present method and HPLC are in good agreement, indicating that the proposed SQDs can serve as a powerful tool for biological analysis.

Correction to: Loop-mediated isothermal amplification for visual detection of Vibrio parahaemolyticus using gold nanoparticles

The published version of this article, unfortunately, contained error. Modifications have been made to the Abstract, Introduction, Results and discussion, and Acknowledgements section. The original article has been corrected.

Temperature Effect Study on Growth and Survival of Pathogenic Vibrio parahaemolyticus in Jinjiang Oyster (Crassostrea rivularis) with Rapid Count Method

The growth of Vibrio parahaemolyticus (V. parahaemolyticus) in oysters during postharvest storage increases the possibility of its infection in humans. In this work, to investigate the growth or survival profiles in different media, pathogenic V. parahaemolyticus in APW, Jinjiang oyster (JO, Crassostrea rivularis) slurry, and live JO were studied under different temperatures. All the strain populations were counted through our double-layer agar plate (DLAP) method. In APW, the pathogenic V. parahaemolyticus showed continuous growth under 15, 25, and 35°C, while a decline in behavior was displayed under 5°C. The similar survival trend of pathogenic V. parahaemolyticus in JO slurry and live JO was observed under 5, 25, and 35°C, except the delayed growth or decline profile compared to APW. Under 15°C, they displayed decline and growth profile in JO slurry and live JO, respectively. These results indicate the different sensitivity of pathogenic V. parahaemolyticus in these matrices to temperature variation. Furthermore, nonpathogenic V. parahaemolyticus displayed little difference in survival profiles when inoculated in live JO under corresponding temperatures. The results indicate that inhibition or promotion effect could be regulated under different storage temperature for both pathogenic and nonpathogenic strains. Besides, the DLAP method showed the obvious quickness and efficiency during the bacteria count.

Facile Synthesis Route of Au-Ag Nanostructures Soaked in PEG

A nanostructured gold-silver soaked in polyethylene glycol 400 (Au-Ag@PEG) is designed using gold(I) chloride and silver nitrate (AgNO3) as precursors and, polyethylene glycol 400 (PEG) as capping agent. The result of the structure characterization using Selected Area Electron Diffraction (SAED) has showed that the synthesized nanomaterial has a good crystallinity while Transmission Electron Microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and Dynamic Light Scattering (DLS) measurements suggest mixed Au-Ag nanoparticles with an average diameter size of around 7 nm and 30 nm for Au and Ag respectively.

Selective synthesis of Fe3O4Au x Ag y nanomaterials and their potential applications in catalysis and nanomedicine

In these recent years, magnetite (Fe3O4) has witnessed a growing interest in the scientific community as a potential material in various fields of application namely in catalysis, biosensing, hyperthermia treatments, magnetic resonance imaging (MRI) contrast agents and drug delivery. Their unique properties such as metal–insulator phase transitions, superconductivity, low Curie temperature, and magnetoresistance make magnetite special and need further investigation. On the other hand, nanoparticles especially gold nanoparticles (Au NPs) exhibit striking features that are not observed in the bulk counterparts. For instance, the mentioned ferromagnetism in Au NPs coated with protective agents such as dodecane thiol, in addition to their aptitude to be used in near-infrared (NIR) light sensitivity and their high adsorptive ability in tumor cell, make them useful in nanomedicine application. Besides, silver nanoparticles (Ag NPs) are known as an antimicrobial agent. Put together, the

Determination of 7 Indictor Polychlorinated Biphenyls (PCBs) Residues in Porphyra by Ultrasonic Extraction and Gas Chromatography (GC)

{\text{Fe}}_{ 3} {\text{O}}_{ 4} {\text{Au}}_{x} {\text{Ag}}_{y} \left( {\left\{ {x,y} \right\} = \{ 0 , 1\} } \right)

PROBLEMS AND SUGGESTIONS FOR QUALITY AND SAFETY OF AQUATIC PRODUCTS IN CHINA

Fe3O4AuxAgyx,y={0,1} nanocomposites with tunable size can therefore display important demanding properties for diverse applications. In this review, we try to examine the new trend of magnetite-based nanomaterial synthesis and their application in catalysis and nanomedicine.