食品成分的高灵敏伏安检测方法研究

发布时间：2018-03-12 09:06

  本文选题：食品分析　切入点：石墨烯　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：石墨烯(Graphene)作为一种新型的碳纳米材料有多种优异性能,如良好的机械强度、大的比表面积以及好的导电性。石墨烯层与层之间存在π-π堆积和较强的范德华力,容易造成石墨烯的团聚,很难均匀分散于水中,这些不利的因素严重影响其在电分析化学中的应用。通过表面功能化的手段来解决这一问题,使石墨烯的优良性能得以充分的发挥。另外,功能化试剂有利于进一步连接或负载金属纳米粒子,从而赋予石墨烯复合材料更为优异的电化学性能。本文利用高分子聚合电解质对石墨烯表面进行功能化修饰,并进一步在其表面负载金属纳米粒子。通过纳米复合物的协同作用,构筑了几种性能优异的电化学传感器。探讨了几种食品成分在所构筑传感器上的电化学行为,为食品分析检测提供了方法学的参考和依据。主要研究工作如下:(1)采用改进的Hummer方法由天然石墨粉制得氧化石墨烯(GO),再以水合肼为还原剂进行还原,同时加入聚苯乙烯磺酸钠(PSS),制备成PSS功能化石墨烯(PSS-GR)复合材料。运用简单的滴涂法构筑了PSS-GR/GCE,并将其应用于橙黄II的检测。通过线性扫描伏安法(LSV)建立了对橙黄II的电化学检测方法,线性范围为3×10-8-5×10-6 mol L-1,检测限为1×10-8 mol L-1,并将该传感器成功地应用于食品样品中橙黄II的检测。(2)通过绿色还原法制备了L-谷胱甘肽(GSH)功能化石墨烯(GR)。GSH分子中的巯基和氧化石墨烯(GO)上的环氧基通过亲质子的开环反应使得GSH以共价键结合在GO上,然后将GO还原,得到GSH修饰的石墨烯(GSH-GR)复合材料,将其滴涂在玻碳电极表面,制得GSH-GR/GCE伏安传感器。该传感器对芦丁具有较强的富集能力和优异的伏安响应性能。在最佳检测条件下利用方波伏安技术(SWV),得到对芦丁响应较宽的线性范围(5×10-9-1×10-6 mol L-1),以及较低的检测限(7×10-10 mol L-1)。此外,所制备的传感器成功用于实际样品中芦丁的分析检测。(3)利用非共价键合法合成聚二烯丙基二甲基氯化铵(PDDA)功能化石墨烯(GR)/铂纳米粒子(Pt NPs)复合材料。用紫外-可见光谱(UV-vis),傅立叶变换红外光谱(FTIR),透射电镜(TEM)和X-射线粉末衍射(XRD)对复合材料进行了表征。将该复合材料用于对玻碳电极的修饰,得到的电化学伏安传感器可实现对没食子酸的灵敏检测。在最优条件下,通过方波伏安法(SWV)获得较宽的线性范围(3×10-8-1×10-6 mol L-1)和较低的检测限(7×10-9 mol L-1)。所建立的伏安方法应用于实际样品中没食子酸的检测并得到满意的结果。(4)通过超声水浴方法合成钯纳米粒子掺杂聚苯乙烯磺酸钠功能化石墨烯(PSS-GR-Pd)复合材料。用紫外-可见光谱(UV-vis),傅立叶变换红外光谱(FTIR),透射电镜(TEM)和X-射线衍射(XRD)对复成材料进行表征。PSS-GR-Pd修饰玻碳电极对苋菜红具有优良的电化学响应,基于此建立了对苋菜红的高灵敏伏安测定方法。在最优实验条件下,通过差示脉冲伏安法(DPV),获得了较宽的线性范围(1×10-7-9×10-6 mol L-1)和较低的检测限(7×10-9 mol L-1)。建立的检测方法成功地应用于饮料中苋菜红的检测,结果满意。
[Abstract]:Shi Moxi (Graphene) as a new type of carbon nano materials have many excellent properties, such as good mechanical strength, large specific surface area and good conductivity. There is a pi pi accumulation and strong van Edward forces between the graphene layers, easy to cause the graphene reunion, it is difficult to evenly disperse in the water, these factors seriously affect its application in Electroanalytical Chemistry. To solve this problem by means of surface functionalization, the excellent properties of graphene into full play. In addition, functional reagents is conducive to further connect or load metal nanoparticles, thus giving graphene composites more electrochemical properties excellent. The polymer electrolyte for functionalization of graphene surface, and further supported metal nanoparticles on its surface. The synergistic effect of nano composite, build a few Electrochemical sensor with excellent properties is discussed. Several kinds of food ingredients in the construction of electrochemical behavior on the sensor for food analysis provides reference and basis for the detection methodology. The main research work is as follows: (1) to graphene oxide by natural graphite powder using improved Hummer method (GO), and then restored using hydrazine as reducing agent and adding sodium polystyrene sulfonate (PSS), prepared PSS functionalized graphene (PSS-GR) composite material. The use of a simple drop coating method to build PSS-GR/GCE, and applied to detect orange II. By linear sweep voltammetry (LSV) was established for electrochemical detection method orange II, the linear range of 3 * 10-8-5 * 10-6 mol L-1, the detection limit is 1 * 10-8 mol L-1, and the detection of the sensor has been successfully applied in food samples of orange II. (2) L- was prepared through the green reduction of glutathione (GSH) function Graphene (GR) and thiol graphene oxide in the molecule of.GSH (GO) on the GSH epoxy covalently bound to GO by ring opening reaction of proton affinity, and the reduction of GO, GSH modified graphene (GSH-GR) composite material is coated on the surface of glassy carbon electrode. Preparation of GSH-GR/GCE electrochemical sensor. The sensor has strong enrichment capacity and excellent performance. The voltammetric response of rutin by square wave voltammetry in the optimal detection conditions (SWV), get a wide range of linear response of rutin (5 * 10-9-1 * 10-6 mol L-1), and low detection limit (7 x 10-10 mol L-1). In addition, the prepared sensor successfully used to detect Rutin in real samples. (3) the use of non covalent binding synthesis of poly diallyl dimethyl ammonium chloride (two PDDA) functionalized graphene (GR) / Pt nanoparticles (Pt NPs) composite material. By UV Vis spectroscopy (UV-v is),鍌呯珛鍙跺彉鎹㈢孩澶栧厜璋，

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