基于石墨烯/离子液体构建免疫传感器快速测定食品中黄曲霉毒素B1

采用壳聚糖、石墨烯和1-丁基-3-甲基咪唑基四氟硼酸盐复合膜修饰玻碳电极,包埋固定黄曲霉毒素B1（aflatoxin B1,AFB1）抗体,构建了一种免疫传感器,用于快速测定食品中的AFB1。在pH值为7.0含1 mmol/LK3[Fe(CN)6]和0.1 mmol/L KCl的磷酸盐缓冲溶液中,基于AFB1抗体与抗原之间的特异性免疫反应,以K3[Fe(CN)6]为探针,运用循环伏安法和差分脉冲伏安法研究免疫反应对传感器响应电流的影响。在优化实验条件下,免疫传感器峰电流的降低值随溶液中AFB1质量浓度对数的增大而增大,且二者在0.1～8.1 ng/mL范围内呈线性关系,其检出限为0.04 ng/mL（RSN=3）。该免疫传感器的稳定性和重复性较好,利用该法对花生和玉米油样品中AFB1进行检测,回收率为94.73%～104.41%,检测结果与高效液相色谱法基本一致,用于食品中AFB1的快速检测是可行的。     

纳米金标记黄曲霉毒素B1新型检测方法

本文建立了两种基于银增强纳米金标记探针的高灵敏度免疫分析方法.方法一是用黄曲霉毒素B1(AFB1)抗体与金标抗原、待测抗原进行竞争免疫反应,然后加入银增强溶液,以金为核沉积生长银,通过检测光密度来确定待测物中AFB1的含量,该方法的检出限可达到0.01 ng/mL.方法二是在前一种方法的基础上,将银化学溶出,通过化学发光法检测沉积的银量来确定待测物中AFB1的含量,该方法的检出限可达到0.002 ng/mL.     

基于石墨烯-壳聚糖复合膜修饰电极的麻保沙星电化学免疫传感器的构建

用氧化石墨烯/壳聚糖复合膜修饰玻碳电极,经电化学还原后,再在修饰电极表面固载麻保沙星抗体,构建一种高灵敏的麻保沙星电化学免疫传感器。用扫描电子显微镜表征氧化石墨烯和氧化石墨烯-壳聚糖复合膜的表面形貌。用循环伏安法和差分脉冲伏安法对电化学免疫传感器的检测条件进行优化。在最适条件下,麻保沙星在2.0～40.0 ng/mL浓度范围内与电极峰值电流呈良好的线性关系,检测限为0.08 ng/mL。对猪肉样和牛奶样进行添加回收,回收率达到84.40%～96.36%。因此,该研究所建立的免疫传感器准确、稳定且灵敏,可用于动物性食品中麻保沙星残留的快速检测。     

基于壳聚糖-纳米金修饰的酪蛋白免疫传感器的研制

在玻碳电极表面修饰壳聚糖和纳米金,以纳米金对抗体等生物分子的良好亲和性,固定抗-αs-酪蛋白(anti-αs-酪蛋白)抗体制得酪蛋白免疫传感器。通过循环伏安法考察电极表面的电化学特性,并对该免疫传感器的性能进行研究。该免疫传感器对以磷酸盐缓冲液溶解的αs-酪蛋白进行检测。响应电流与酪蛋白抗原质量浓度的对数在1～10000ng/mL的范围内线性相关。该免疫传感器制作简单,成本较低,操作方便,可应用于牛奶质量和非乳蛋白掺杂使假的检测。     

基于石墨烯/离子液体构建免疫传感器快速测定食品中黄曲霉毒素B

采用壳聚糖、石墨烯和1-丁基-3-甲基咪唑基四氟硼酸盐复合膜修饰玻碳电极,包埋固定黄曲霉毒素B_1(aflatoxin B_1,AFB_1)抗体,构建了一种免疫传感器,用于快速测定食品中的AFB_1。在pH值为7.0含1 mmol/L K_3[Fe(CN)_6]和0.1 mmol/L KCl的磷酸盐缓冲溶液中,基于AFB_1抗体与抗原之间的特异性免疫反应,以K_3[Fe(CN)_6]为探针,运用循环伏安法和差分脉冲伏安法研究免疫反应对传感器响应电流的影响。在优化实验条件下,免疫传感器峰电流的降低值随溶液中AFB_1质量浓度对数的增大而增大,且二者在0.1~8.1 ng/mL范围内呈线性关系,其检出限为0.04 ng/mL(R_(SN)=3)。该免疫传感器的稳定性和重复性较好,利用该法对花生和玉米油样品中AFB_1进行检测,回收率为94.73%~104.41%,检测结果与高效液相色谱法基本一致,用于食品中AFB_1的快速检测是可行的。     

基于纳米金-石墨烯-壳聚糖复合物修饰电极的免疫传感器检测己烯雌酚

研究在磷酸缓冲介质(PBS)中,一种检测己烯雌酚抗原的新型免标记电化学免疫传感器的制备及应用。首先将纳米金(AuNP)修饰在电极上,然后将石墨烯(Gr)-壳聚糖(CS)复合物饰于玻碳电极表面,通过循环伏安法对修饰的电极进行表征。以[Fe(CN)6]3-/4-为氧化-还原探针,基于己烯雌酚抗原抗体反应引起[Fe(CN)6]3-/4-探针的电流响应的变化,来实现对己烯雌酚抗原的检测。己烯雌酚抗原的质量浓度在0.5～1500.0ng/mL范围,与峰电流呈良好的线性关系,相关系数为0.985,检测限为0.1ng/mL。该传感器具有良好的重现性和稳定性,用于动物组织和奶粉样品的测定获得满意结果。     

DNA损伤传感器制备及其用于饲料中黄曲霉毒素B1的快速检测

本文利用巯基化单链DNA(ssDNA)自组装修饰在金电极表面,制备了ssDNA修饰金电极(ssDNA/Au);在最优化条件下,与互补片段杂交制备了相应的双链DNA修饰金电极(dsDNA/Au),构建了一种快速、简便、价廉的检测黄曲霉毒素B1(AFB1)的新型电化学DNA生物传感器。采用循环伏安法(CV)和示差脉冲伏安法(DPV)等电化学方法表征了电子媒介体铁氰化钾和亚甲基蓝(MB)在ssDNA/Au和dsDNA/Au界面上的电化学行为。一定浓度的黄曲霉毒素B1(AFB1)诱导dsDNA/Au造成DNA损伤,使得MB电化学信号降低,实现了快速检测AFB1。在最优化条件(在4℃下,ssDNA在金电极上自组装14 h,与cDNA在37℃下杂交2 h,制备了dsDNA/Au电极;37℃下,AFB1溶液诱导损伤DNA 22 min后),该方法对AFB1的线性检测范围为10~500 ng/mL,加标回收率在95.99%~104.57%。建立的AFB1诱导DNA损伤方法可以实现对AFB1快速、简便、准确的定量检测。     

纳米免疫传感器法快速测定粮油食品中的黄曲霉毒素B1

摘要：本文以改性壳聚糖为固定化材料,包埋固定纳米金胶微粒及黄曲霉毒素B1抗体制备信号放大型纳米免疫传感器,建立了免疫传感器测定黄曲霉毒素B1的方法;优化了纳米免疫传感器的制备条件及检测参数;基于AFB1抗体与抗原之间的特异性免疫反应,以K3[Fe(CN)6]为探针,利用循环伏安法和差分脉冲伏安法研究了其免疫反应对传感器响应电流的影响,结果表明免疫响应电流与底液中AFB1的浓度在0.1～1.1 ng mL-1范围内成线性关系,其校正曲线方程为IP =-4.9274x +15.108（R 2= 0.9912）,其最低检测限为0.05 ng mL-1（S/N=3）;该免疫传感器的稳定性和重现性较好。利用该法对花生油、玉米油等实际样品中的AFB1进行了检测,其回收率为在87.8～98.2%,检测精确度优于ELISA试剂盒法,用于粮油食品中黄曲霉毒素的快速检测是可行的。     

基于纳米金电化学免疫传感器测定牛奶中的青霉素G

利用吸附法将青霉素G抗体固定于纳米金修饰的玻碳电极表面,制备用于检测青霉素G的电化学免疫传感 器,建立高度灵敏的一步直接电化学免疫法。纳米金的强吸附和导电作用,提高了青霉素G抗体的固定量和电化学 灵敏度。在优化条件下,该传感器的响应电流与青霉素质量浓度的对数在0.04～40.00 ng/mL范围内呈良好的线性关 系,相关系数为0.988 4,检测限为2.49 ng/mL,该法成功的实现了对牛奶中青霉素G的检测。     

基于上转换纳米颗粒和金纳米颗粒的Cd2+免疫检测新方法

基于上转换纳米颗粒(UCNPs)和金纳米颗粒(AuNPs)间的荧光共振能量转移(FRET)和抗原抗体的识别作用构建了Cd~(2+)的免疫检测平台。制备水溶性UCNPs表面修饰Cd-抗原作为能量供体探针,同时在AuNPs表面修饰Cd-抗体作为能量受体探针。抗原-抗体的免疫结合使得UCNPs和AuNPs发生FRET过程,引起UCNPs荧光猝灭;当检测体系中存在Cd~(2+)时,Cd~(2+)与UCNPs-抗原竞争性地结合AuNPs-抗体,从而抑制了FRET过程,荧光信号值随着Cd~(2+)质量浓度的增加而增加。结果表明,该方法检测范围为0.01～10 ng/mL,检出限可达0.01 ng/mL。将该方法应用于自来水样品中Cd~(2+)的检测,当加标水平为0.1、1、10 ng/mL时,回收率为98%～109%,相对标准偏差为3.4%～4.1%。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press