【作者】 朱刚兵；

【导师】 陈金华；

【作者基本信息】 湖南大学 ， 分析化学， 2013， 博士

【摘要】 持久性有机污染物（Persistent organic pollutants, POPs）是指能持久存在于环境中，可通过生物食物链（网）累积、并对人类健康和环境造成有害影响的化学物质。相比于常规污染物，POPs对人类健康和自然环境的危害更大：在自然环境中滞留时间长，极难降解，毒性极强，并能导致全球性的传播。在被生物体摄入后不易分解，并沿着食物链浓缩放大。而位于生物链顶端的人类则把这些毒性放大到了7万倍。POPs不仅会对人体本身造成影响（如：免疫能力下降、内分泌失调、内脏器官坏死、新陈代谢受阻、诱发癌症等），还可能影响到后代的正常生长和发育（如畸形、智力发育缓慢等）。因此，对POPs实现准确的定性和定量分析具有重大的价值和意义。β-环糊精是直链淀粉在芽孢杆菌产生的环糊精葡萄糖基转移酶作用下生成的含有7个葡萄糖单元的环状低聚糖，它具有环内疏水环外亲水的特性，同时能够选择性的识别许多如有机分子等客体形成主客体包络物。另一方面，纳米碳材料（如碳纳米管、石墨烯、碳空心球）具有大的表面积，优良的导电性和电催化性能。本文主要结合β-环糊精和碳材料的协同作用，发展了一系列电化学检测POPs的新材料和新方法：（1）成功制备了巯基-β-环糊精（SH-β-CD）功能化修饰金纳米粒子/氮掺杂中空碳微球（AuNPs/HNCMS）复合材料，实现了对萘酚异构体高灵敏度的电化学传感分析。实验结果显示，1-萘酚（1-NAP）和2-萘酚（2-NAP）在HS-β-CD/AuNPs/HNCMS修饰玻碳（GC）电极表面氧化峰电流远远大于AuNPs/HNCMS/GC、 HNCMS/GC、裸GC电极表面的氧化峰电流。与已有的萘酚电化学检测方法相比，通过本方法得出的1-NAP和2-NAP的检测限（1.0nM和1.2nM）分别降低了4倍和两个数量级，两者的线性范围均为2-150nM。（2）采用湿化学法制备了β-环糊精-铂纳米粒子/石墨烯纳米复合材料（β-CD-PtNPs/GNs），采用原子力显微镜、透射电子显微镜、傅立叶变换红外光谱和电化学方法对其进行表征，实现了对萘酚的超灵敏电化学检测。测量结果显示，与PtNPs/GNs/GC、β-CD/GNs/GC、GNs/GC、裸GC电极相比，萘酚在β-CD-Pt NPs/GNs/GC电极上的氧化峰电流最大。另外，与已有的萘酚电化学传感器相比，该传感器对1-NAP的检测限（0.23nM）降低了大约一个数量级，2-NAP的检测限（0.37nM）降低了大约三个数量级。（3）以3,4,9,10-苝四酸（PTCA）作为“桥”将氨基环糊精（NH₂-β-CD）固定到石墨烯（GN）表面，制备了环糊精功能化石墨烯纳米复合材料（CD-PTCA-GN），采用用傅里叶红外光谱、热重分析、原子力显微镜和电化学方法对该复合物进行了表征，实现了具有代表性的四种有机污染物[1-萘胺（1-NA），五氯苯酚，9-羧酸蒽（9-ACA）和双酚A]的电化学检测。研究结果显示，该材料修饰GC电极对上述四种污染物均具有很好的电催化作用。以1-萘胺为模型，详细探讨了CD-PTCA-GN复合材料修饰电极对1-萘胺的电化学传感的研究结果，线性响应范围达10nM-550nM，检测限达1.0nM。（4）将β-CD固定到PTCA功能化的单壁碳纳米管（SWCNT）上面，制备了β-CD功能化SWCNTs复合物（β-CD-PTCA-SWCNTs），采用傅里叶红外光谱、投射电子显微镜、热重分析仪、拉曼光谱和电化学方法对该复合物进行了表征，并应用于9-ACA的电化学传感。由于SWCNTs优良的电学性能和β-CD的分子识别能力，9-ACA在β-CD/PTCA/SWCNTs修饰GC电极（β-CD-PTCA-SWCNTs/GC）表面的氧化峰电流分别是SWCNTs/GC、GC的4倍、31.2倍，线性响应范围达2nM-140nM，检测限达0.65nM。（5）基于β-环糊精/聚乙酰苯胺/电沉积石墨烯（β-CD/PNAANI/EG）膜与探针分子和被分析物之间竞争，发展了一种既灵敏又具选择性的新型双信号电化学检测电活性有机污染物方法。在此，以罗丹明B（RhB）和1-氨基芘（1-AP）分别作为探针和目标物分子。由于主客体包络作用，RhB分子可以进入β-CD内腔，因此在β-CD/PNAANI/EG修饰GC电极上会明显的出现RhB氧化峰。然而，加入1-AP后，它将与RhB产生竞争性结合β-CD内腔并取代RhB分子，从而使RhB的氧化峰下降同时出现1-AP的氧化峰，两者信号的改变值大小与1-AP的浓度成线性关系。以两者信号改变值的绝对值之和为响应信号所获得的对1-AP的检测限比单独作为响应信号所获得的检测限要低很多。此外，通过一种简单的电聚合方法，我们制备了聚噻唑（PAMT）修饰GC电极（PAMT/GC），并将该修饰电极应用于9-ACA的电化学检测。由于PAMT大的表面积、好的电催化性能和电学性能，PAMT/GC对9-ACA的检测限达0.012μM （S/N=3），线性响应范围达0.7¹.1μM。此外，本文所制备的PAMT/GC电极在检测9-ACA时不会产生电极污染，从而使得该电极的重现性和稳定性良好，有利于实际应用。更多还原

【Abstract】 Persistent organic pollutants （POPs） are chemical substances that persist in theenvironment, bioaccumulate through the food web, and pose a risk of causingadverse effects to human health and the environment. Compared to generalpollutants, POPs are more harmfull. It’s very difficult to decompound POPsexisted in biology and the POPs can accumulate in human body through the foodchain. These will not only affect the human body itself, resulting in endocrinedisorder, weakened immune system, metabolic disruption, necrosis of internalorgans, causing cancer, etc., but also affect the normal development and growth oftheir offspring, who may be deformity or slow mental development. Therefor, it’sof great significance to achieve the qualitative and quantitative determinations ofPOPs.β-cyclodextrins （β-CD） is oligosaccharides composed of seven glucose units,which is toroidal in shape with a hydrophobic inner cavity and a hydrophilicexterior. It is well known that β-CD has high molecular selectivity andenantioselectivity, various organic, inorganic, and biological guest molecules canbe bound selectively in the inner cavity of β-CD to form stable host-guestinclusion complexes. On the other hand, carbon materials, sucs as carbon nanotube,graphene and hollow carbon microspheres, have high specific surface area, goodchemical stability and electrochemical properties. Herein, based on the synergeticeffects from carbon materials and β-CD, we developed a series of nanohybrids andmethods to detect POPs ultrasensitively by electrochemical technology:（1） Gold nanoparticles （Au NPs）/hollow nitrogen-doped carbon microspheres（HNCMS） hybrids （Au NPs/HNCMS） were prepared and functionalized bythiolated-β-cyclodextrin （HS-β-CD） for the first time, and then appliedsuccessfully in sensitive and simultaneous electrochemical detection of naphthols.The results show that the oxidation peak currents of naphthols obtained on theHS-β-CD/AuNPs/HNCMS modified glassy carbon （GC） electrode are much higherthan that on the HS-β-CD/HNCMS/GC, AuNPs/HNCMS/GC, HNCMS/GC andbare GC electrodes. Additionally, compared with the other electrochemical sensorsdeveloped previously, the proposed electrode demonstrates the improved detectionlimits of about four times for1-NAP （1.0nM） and two orders of magnitudefor2-NAP （1.2nM）. The linear response range for both1-NAP and2-NAP are2– 150nM.（2） β-cyclodextrin （β-CD）-platinum nanoparticles （Pt NPs）/graphenenanosheets （GNs） nanohybrids （β-CD-PtNPs/GNs） were prepared for the first timeusing a simple wet chemical method and characterized by atomic force microscopy,transmission electron microscopy, Fourier transform infrared spectroscopy, andelectrochemical methods, and then applied in the ultrasensitive electrochemicaldetection of naphthol isomers. The results show that the oxidation peak currents ofnaphthol isomers obtained at the glassy carbon （GC） electrode modified withβ-CD-PtNPs/GNs are much higher than those at the β-CD/GNs/GC,PtNPs/GNs/GC, GNs/GC, and bare GC electrodes. Additionally, compared withother electrochemical sensors developed previously, the proposed electrode resultsin decreased detection limits of about one order of magnitude for1-NAP （0.23nM）and three orders of magnitude for2-NAP （0.37nM）.（3） Using3,4,9,10-perylene tetracarboxylic acid as a bridge to connectmono（6-ethanediamine-6-deoxy）-b-cyclodextrin （NH₂-β-CD）to the surface ofgraphene, noncovalently functionalized graphene nanosheets （CD-PTCA-GNs） aresynthesized for the first time. The as-prepared CD-PTCA-GNs were characterizedby Fourier transform infrared spectroscopy, thermogravimetric analysis, atomicforce microscopy, and electrochemical methods. The electrocatalytic activitiestoward several organic pollutants at the glassy carbon （GC） electrode modifiedwith CD-PTCA-GNs were investigated, all of which show a remarkable increase inelectrochemical performance relative to the bare GC and GNs/GC electrodes.1-aminonaphthalene （1-NA） was used as the representative analyte to demonstratethe sensing performance of the CD-PTCA-GNs. The results show that the linearresponse range of1-NA is10–550nM with the detection limit of1.0nM （S/N=3）,thus implying that the CD-PTCA-GNs organic–inorganic nanohybrids will havepromising applications in organic pollutants analysis and sensors.（4） We reported a simple and facile approach to synthesis β-cyclodextrinnon-covalently functionalized single-walled carbon nanotubes bridged by3,4,9,10-perylene tetracarboxylic acid （β-CD-PTCA-SWCNTs）, and Fourier transforminfrared spectroscopy, transmission electron microscopy, thermogravimetricanalysis, Raman spectroscopy and electrochemical methods were used tocharacterize the as-prepared functionalized SWCNTs. Furthermore, theβ-CD-PTCA-SWCNTs were applied successfully to detect9-AnthracenecarboxylicAcid by electrochemical methods. The results show that the oxidation peak current of9-ACA at β-CD-PTCA-SWCNTs modified GC electrode is4.0and31.2times higher than that at the SWCNTs/GC and bare GC electrodes, respectively, and the proposed modified electrode has a linear response range of2.00to140.00nM with a detection limit of0.65nM （S/N=3） towards9-ACA, due to the synergetic effects from SWCNTs （good electrochemical properties and large surface area） and β-CD （a hydrophilic external surface, high supramolecular recognition and enrichment capability）.（5） Based on the competitive host-guest interaction between β-cyclodextrin/poly（N-acetylaniline）/electrogenerated-graphene （β-CD/PNAANI/EG） film and probe or target molecules, a new dual-signalling electrochemical sensing method has been developed for sensitive and selective determination of organic pollutants. As the model, rhodamine B （RhB） and1-aminopyrene （1-AP） were adopted as the probe and target molecules, respectively. Due to the host-guest interaction, RhB molecules can entry into the hydrophobic inner cavity of β-CD, and the β-CD/PNAANI/EG modified glassy carbon electrode displays a remarkable oxidation peak of RhB. While in the presence of1-AP, competitive association to the β-CD occurs and the RhB molecules are displaced by1-AP. This results in that the oxidation peak current of RhB decreases and the oxidation peak current of1-AP appears, and the changes of dual signals are linear with the concentration of1-AP. When "ΔI1-AP+|ΔIRhB|"（ΔI1-AP and ΔIRhB are the change values of the oxidation peak currents of1-AP and RhB, respectively.） is used as the response signal to quantitatively determine the concentration of1-AP, the detection limit is much lower than that by using ΔI1-AP or ΔIRhB as the response signal. This dual-signalling sensor can provide more sensitive target recognition, and will have important applications in the sensitive and selective electrochemical determination of electroactive organic pollutants.Additionally, an ultrathin film modified glassy carbon （GC） electrode was prepared by electropolymerization of5-amino-1,3,4-thiadiazole-2-thiol （AMT） on the GC electrode （PAMT/GC） and used to detect9-ACA. Compared to the GC electrode, the PAMT/GC electrode shows more excellent stability and reproducibility, and meanwhile exhibits higher electrochemical response of9-ACA due to the unique properties of PAMT such as large surface area, good electronic properties and catalytic ability. The linear range for9-ACA detection is from7.0x10-8M to1.1×10-6M and the detection limit is1.2×10-8M （S/N=3）. Finally, the proposed methodology was successfully applied to the detection of9-ACA inwater samples.更多还原