【作者】 李慧；

【导师】 李方；

【作者基本信息】 天津大学 ， 材料化学， 2014， 硕士

【摘要】 本文主要制备了Ag纳米粒子-壳聚糖-磺化石墨烯复合材料，研究了它的制备工艺，并用傅立叶转换红外光谱、紫外可见分光光谱仪、X射线衍射、透射电子显微镜、拉曼光谱对材料进行了表征。此外，本文还用制得的Ag纳米粒子-壳聚糖-石墨烯复合材料修饰电极，构建过氧化氢无酶生物传感器并系统的研究了它的性能，得到了以下结论：(1)采用原位还原法，利用壳聚糖还原硝酸银制备得到Ag纳米粒子-壳聚糖，此过程中壳聚糖既充当还原剂又充当固定剂。研究了反应时间、反应温度、硝酸银浓度、壳聚糖与硝酸银的浓度比等因素对反应的影响，通过优化反应条件，最终制得的Ag纳米粒子-壳聚糖复合材料中银纳米颗粒呈现圆球状，粒径大小主要集中在5nm以下，均匀分散在壳聚糖上。(2)首先采用改进Hummer法制得氧化石墨烯(GO)，然后用三步法，第一步，用抗坏血酸预还原氧化石墨烯，第二步，用芳香基重氮盐磺化，第三步用柠檬酸钠进行完全还原合成了磺化石墨烯(GS)，有效避免了在氧化还原过程中石墨烯大量团聚的现象。对制得的磺化石墨烯进行表征，结果表明：对氨基苯磺酸成功地接枝到了石墨烯上，所制得的磺化石墨烯表面平整，透明度高，层数较少。(3)带正电的Ag纳米粒子-壳聚糖复合材料与带负电的磺化石墨烯通过静电作用组装合成Ag纳米粒子-壳聚糖-磺化石墨烯复合材料。表征结果表明，制得的Ag纳米粒子-壳聚糖-磺化石墨烯复合材料为三层结构，其中壳聚糖扮演了雅努斯（希腊神话中的双面神）的角色，一面负载银纳米粒子，另一面与磺化石墨烯静电自组装，复合过程没有影响银纳米粒子的粒径和分散性。(4)利用Ag纳米粒子-壳聚糖-磺化石墨烯复合材料直接修饰玻炭电极，制得无酶过氧化氢传感器，该传感器表现出了少于2s的快速响应时间，在0.1mM到10mM范围内，电流响应与过氧化氢的浓度呈现很好的线性关系（r=0.998）；估测检出限为4μΜ(S/N=3)。更多还原

【Abstract】 In this paper, Nano-Ag particles-chitosan-sulfonated graphene composites weresynthesized. The composites were characterized systematically by FT-IR, XRD,UV-VIS, TEM and Raman. Nano-Ag particles-chitosan-graphene composites wereapplied to modify electrode, then noenzymatic H2O2sensor was constructed and itsperformances were studied systematically.The main results were as follows:(1) AgNPs-CS (Nano-Ag particles-chitosan composites) were prepared by adop--tting in-situ reduction.Chitosan not only acted as the reducing agent for the silvernitrate, but also stabilized the Nano-Ag particles by anchoring them. Then we studiedthe effects of reaction time, reaction temperature, concentration of silver nitrate,concentration of chitosan, concentration ratio of silver nitrate and chitosan on thereaction. By optimizing the reaction conditions, spherical nano-Ag particles wereshowed in AgNPs-CS composites and nano-Ag particles disperse evenly on thesurface of chitosan with mean particle size under5nm.(2) GO (graphene oxide) was prepared by a modified Hummer’s method, Theprocess of synthesizing GS (sulfonated graphene) from GO consists of three steps:1)pre-reduction of graphene oxide with ascorbic acid;2) sulfonation with the aryldiazonium salt of sulfanilic acid; and3) post-reduction with sodium citrate.The GSwas characterized systematically, the results stated that sulfanilic successfully graftedonto the graphene. The prepared GS has smooth surface, transparent, clean andless-layers.(3) AgNPs-CS-GS (Nano-Ag particles-chitosan-sulfonated graphene) compositeswere formed by electrostatically-assembling between the positively charged chitosan--silver nanoparticle composites and negatively charged sulfonated graphene. Theresults showed that AgNPs-CS-GS is three-layer structure, chitosan played a role as’janus’, one side is used to load nano-Ag particles, and the other side is combinedsulfonated graphene by electrostatically-assembling. The particle size and dispersionof nano-Ag particles was not affected in the composite process.(4) AgNPs-CS-GS (Nano-Ag particles-chitosan-sulfonated graphene) compositeswere used to modify glassy carbon electrode directly to obtain a noenzymatic H2O2sensor. This noenzymatic H2O2sensor showed a fast amperometric response time of less than2s. In the range of0.1mM to10mM, the current response was linear to theH2O2concentration(r=0.998) and the detection limit was found to be4μΜ (S/N=3)更多还原