Co-reporter:Rui Jin;Daqian Song;Huixia Xiong;Lisha Ai;Pinyi Ma
Luminescence 2016 Volume 31( Issue 2) pp:499-506
Publication Date(Web):
DOI:10.1002/bio.2988
Abstract
Magnetic core/shell Fe3O4/Au nanoparticles were used in the determination of drug binding to bovine serum albumin (BSA) using a fluorescence spectroscopic method. The binding constants and number of binding sites for protein with drugs were calculated using the Scatchard equation. Because of their superparamagnetic and biocompatible characteristics, magnetic core/shell Fe3O4/Au nanoparticles served as carrier proteins for fixing proteins. After binding of the protein to a drug, the magnetic core/shell Fe3O4/Au nanoparticles–protein–drug complex was separated from the free drug using an applied magnetic field. The free drug concentration was obtained directly by fluorescence spectrometry and the proteins did not influence the drug determination. So, the achieved number of binding sites should be reliable. The binding constant and site number for ciprofloxacin (CPFX) binding to BSA were 2.055 × 105 L/mol and 31.7, and the corresponding values for norfloxacin (NOR) binding to BSA were 1.383 × 105 L/mol and 38.8. Based on the achieved results, a suitable method was proposed for the determination of binding constants and the site number for molecular interactions. The method was especially suitable for studies on the interactions of serum albumin with the active ingredients of Chinese medicine. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Qiong Wu;Daqian Song;Di Zhang
Microchimica Acta 2016 Volume 183( Issue 7) pp:2177-2184
Publication Date(Web):2016 July
DOI:10.1007/s00604-016-1853-0
The article describes a wavelength modulation surface plasmon resonance (SPR) biosensor for human IgG. The sensor is based on the use of silver nanocubes (SNCs) and carboxy-functionalized graphene oxide (cGO). The surface of the SNCs was modified with 3-mercaptopropinic acid by silver-thiol chemistry, and this protects the SNCs from oxidation. The cGO possesses abundant carboxy groups that allow high-density immobilization of anti-human IgG on the gold film of the SPR chip. Successful conjugation to the surface was demonstrated by X-ray photoelectron spectroscopy. The SPR biosensor responds to human IgG in the 0.075 to 40 μg mL-1 concentration range. The limit of quantification (LOQ) is smaller by factors of 32, 8 and 4 compared to (a) a conventional sensor, (b) a GO-based sensor, and (c) a cGO-based sensor. The detection scheme presented here offers a versatile and sensitive platform also for determination of other proteins if the corresponding receptors are available.
Co-reporter:Bo Xu, Yuanpeng Wang, Rui Jin, Xinpei Li, Daqian Song, Hanqi Zhang and Ying Sun
Analytical Methods 2015 vol. 7(Issue 4) pp:1606-1614
Publication Date(Web):02 Jan 2015
DOI:10.1039/C4AY02645D
Magnetic Fe3O4@polyaniline (Fe3O4@PANI) particles were successfully prepared and used as an adsorbent in the magnetic solid-phase extraction of Sudan dyes in environmental water samples. The Fe3O4@PANI particles adsorbed analytes were isolated from the sample matrix using an external magnetic field. The analytes were separated and determined by ultrafast liquid chromatography. Significant influential factors, including amount of Fe3O4@PANI particles, pH value, ion strength, extraction time, type of desorption solvent, volume of desorption solvent, desorption time and sample volume, were optimized. Satisfactory extraction recoveries were obtained with only 8 mg of Fe3O4@PANI particles. In addition, the Fe3O4@PANI particles can be reused after a facile washing process. The limits of detection for Sudan I, II, III and IV were 0.041, 0.080, 0.147 and 0.151 ng mL−1, respectively. The intra-day and inter-day precisions with relative standard deviations were 1.3–5.4% and 2.6–7.3%, respectively. Recoveries obtained by analyzing spiked environmental water samples were between 92.4% and 106.9%.
Co-reporter:Qiong Wu;Daqian Song;Di Zhang;Hua Zhang;Yaying Ding;Yong Yu
Microchimica Acta 2015 Volume 182( Issue 9-10) pp:1739-1746
Publication Date(Web):2015 July
DOI:10.1007/s00604-015-1497-5
A new SPR sensing substrate was fabricated that is based on the use of graphene oxide (GO) and gold bipyramids (GBPs). It can substantially improve the sensitivity of wavelength modulation SPR biosensors. First, a support consisting of a sheet of single layered GO was prepared, and its morphology and thickness were determined by atomic force microscopy (AFM). GBPs were synthesized and modified with staphylococcal protein A (SPA) for the oriented immobilization of antibody. GBPs modified with SPA were assembled on GO sheets through covalent attachment. The resulting SPR biosensor exhibits a highly sensitive response to rabbit IgG in the 0.15–40 μg mL−1 concentration range. The limit of quantification is better by factors of 4 and 16 compared to those obtained with gold nanoparticle-based, and conventional gold film-based sensors, respectively. In our expectation, this GBP-based SPR biosensor has a wide scope in that it may be employed to develop detection schemes for many other biomolecules by changing the corresponding receptor on its surface.
Co-reporter:Bo Xu;Daqian Song;Yuanpeng Wang;Yan Gao;Bocheng Cao;Hanqi Zhang
Journal of Separation Science 2014 Volume 37( Issue 15) pp:1967-1973
Publication Date(Web):
DOI:10.1002/jssc.201400317
In situ ionic-liquid-dispersive liquid–liquid microextraction was introduced for extracting Sudan dyes from different liquid samples followed by detection using ultrafast liquid chromatography. The extraction and metathesis reaction can be performed simultaneously, the extraction time was shortened notably and higher enrichment factors can be obtained compared with traditional dispersive liquid–liquid microextraction. When the extraction was coupled with ultrafast liquid chromatography, a green, convenient, cheap, and efficient method for the determination of Sudan dyes was developed. The effects of various experimental factors, including type of extraction solvent, amount of 1-hexyl-3-methylimidazolium chloride, ratio of ammonium hexafluorophosphate to 1-hexyl-3-methylimidazolium chloride, pH value, salt concentration in sample solution, extraction time and centrifugation time were investigated and optimized for the extraction of four kinds of Sudan dyes. The limits of detection for Sudan I, II, III, and IV were 0.324, 0.299, 0.390, and 0.655 ng/mL, respectively. Recoveries obtained by analyzing the seven spiked samples were between 65.95 and 112.82%. The consumption of organic solvent (120 μL acetonitrile per sample) was very low, so it could be considered as a green analytical method.
Co-reporter:Yan Gao, Yuanpeng Wang, Bo Xu, Hanqi Zhang, Daqian Song and Ying Sun
Analytical Methods 2014 vol. 6(Issue 12) pp:4455-4461
Publication Date(Web):17 Mar 2014
DOI:10.1039/C4AY00142G
A simple, rapid and effective extraction method based on matrix solid phase dispersion (MSPD) and ultrafast liquid chromatographic (UFLC) was developed and validated for the simultaneous cleaning-up and quantitative extraction of illegal dyes (Sudan I–IV) from the roots of Salvia miltiorrhiza Bunge. The experiment parameters, such as dispersing sorbent, the ratio of sorbent–sample, washing solvent and elution solvent were evaluated to find the optimal MSPD conditions. The optimal conditions were 0.5 g of Salvia miltiorrhiza Bunge, 1.0 g of silica gel as dispersing sorbent, a volume of 10 mL of water as the washing solvent and 4 mL of acetonitrile–methanol (9:1, v/v) as the elution solvent. Under these conditions good linearity for all the Sudan dyes ranged from 0.10 μg g−1 to 10 μg g−1 (r2 ≥ 0.9992). The recoveries at three spiked levels (0.1, 1.0, 5.0 μg g−1) were between 80.6% and 96.1% with relative deviations (RSDs) ranging from 2.3% to 8.6%. The limits of detection ranged between 0.013 and 0.024 μg g−1 which were twenty times lower than the values required by European regulations. This method has potential to be applied for the determination of illegal dyes in complicated traditional Chinese herb materials.
Co-reporter:Jing Wang, Daqian Song, Hua Zhang, Jia Zhang, Yue Jin, Hanqi Zhang, Hao Zhou, Ying Sun
Colloids and Surfaces B: Biointerfaces 2013 Volume 102() pp:165-170
Publication Date(Web):1 February 2013
DOI:10.1016/j.colsurfb.2012.08.040
A novel method immunosensor based on chemically functionalized Fe3O4/Ag/Au nanocomposite was developed. Fe3O4/Ag seeds were coated with Au and Fe3O4/Ag/Au nanocomposites were obtained. The nanocomposites could be obtained without violent stirring and the operation was easy and convenient. The magnetic nanocomposites can be easily immobilized on Au film of the surface plasmon resonance (SPR) biosensor with a magnetic pillar. The immobilization of Fe3O4/Ag/Au nanocomposites on the Au film leads to a large shift in resonance wavelength, which is due to the increase of the sensing membrane thickness, high dielectric constant of Ag and Au particles, and electromagnetic coupling between Fe3O4/Ag/Au nanocomposites and the Au film. The effects of Fe3O4/Ag/Au nanocomposites on the sensitivity of SPR biosensor were also investigated. As a result, the biosensor based on Au film shows a response for dog IgG in the concentration range of 1.25–20.00 μg ml−1, whereas the SPR biosensor based on Fe3O4/Ag/Au nanocomposites shows a response for dog IgG in the concentration range of 0.15–40.00 μg ml−1. The sensitivity of the SPR biosensor based on Fe3O4/Ag/Au nanocomposites is higher than that based on Au film.Graphical abstractA schematic diagram of the immobilization of antibody on the surface of the Au film. () Fe3O4/Ag/Au nanocomposites, () Fe3O4 nanoparticles () antibody, () antigen.Highlights► Fe3O4/Ag/Au composites were synthesized. ► Two types of SPR biosensors were prepared. ► The magnetic composites can be easily immobilized on the surface of SPR biosensor. ► The magnetic composites could enhance the sensitivity of the SPR biosensor.
Co-reporter:Hua Zhang, Daqian Song, Shang Gao, Jia Zhang, Hanqi Zhang, Ying Sun
Sensors and Actuators B: Chemical 2013 Volume 188() pp:548-554
Publication Date(Web):November 2013
DOI:10.1016/j.snb.2013.07.055
Novel surface plasmon resonance (SPR) biosensors based on Au-graphene (Au-Gra) nanohybrids and Ag-graphene (Ag-Gra) nanohybrids for the detection of mouse IgG were developed. The biosensors proposed are label free, and have high sensitivity and selectivity for biosensing. Au-Gra and Ag-Gra nanohybrids were synthesized in a simple, effective and rapid way, and further characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and UV–vis absorption spectroscopy. These nanohybrids were assembled on the Au film through 1,6-hexanedithiol by covalent attachment. And the antibody was bound to the nanohybrids through 3-mercaptopropinic acid. Some experimental conditions were determined and optimized. In the optimal conditions, the biosensors based on Au-Gra nanohybrids and Ag-Gra nanohybrids show a good response to mouse IgG in the concentration range of 0.30–40.00 μg mL−1 and 0.15–40.00 μg mL−1, respectively. While, the biosensor unmodified with nanohybrids shows a response to mouse IgG in the concentration range of 2.50–40.00 μg mL−1. As a result, the performance of the biosensor based on metal nanoparticles decorated with graphene has been improved significantly.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 12) pp:
Publication Date(Web):
DOI:10.1039/C4AY00142G
A simple, rapid and effective extraction method based on matrix solid phase dispersion (MSPD) and ultrafast liquid chromatographic (UFLC) was developed and validated for the simultaneous cleaning-up and quantitative extraction of illegal dyes (Sudan I–IV) from the roots of Salvia miltiorrhiza Bunge. The experiment parameters, such as dispersing sorbent, the ratio of sorbent–sample, washing solvent and elution solvent were evaluated to find the optimal MSPD conditions. The optimal conditions were 0.5 g of Salvia miltiorrhiza Bunge, 1.0 g of silica gel as dispersing sorbent, a volume of 10 mL of water as the washing solvent and 4 mL of acetonitrile–methanol (9:1, v/v) as the elution solvent. Under these conditions good linearity for all the Sudan dyes ranged from 0.10 μg g−1 to 10 μg g−1 (r2 ≥ 0.9992). The recoveries at three spiked levels (0.1, 1.0, 5.0 μg g−1) were between 80.6% and 96.1% with relative deviations (RSDs) ranging from 2.3% to 8.6%. The limits of detection ranged between 0.013 and 0.024 μg g−1 which were twenty times lower than the values required by European regulations. This method has potential to be applied for the determination of illegal dyes in complicated traditional Chinese herb materials.
