【作者】 李新；

【导师】 黄新堂；

【作者基本信息】 华中师范大学 ， 凝聚态物理， 2011， 博士

【摘要】 对葡萄糖的传感在生物科技、医疗诊断和食品工业等研究领域具有十分重要的意义。酶类的葡萄糖生物传感器具有良好的选择性和较高的灵敏度。但是由于酶非常容易失活、酶的固定存在一定难度,导致酶类的葡萄糖传感器制作过程复杂、制备成本高而且使用寿命短。因此,非酶的葡萄糖传感器也更多的受到了人们的关注。报道显示镍基的纳米材料,已经被用于对葡萄糖的非酶的探测,并且取得了良好的效果。然而在传统的电极修饰中,活性材料的合成和在电极表面的固定是分两步完成的。这不仅让屯极的制备过程变的复杂,也不能在电极表面上形成有序的纳米结构。这将在一定程度上限制镍基纳米材料在非酶的葡萄糖传感中的应用。因此,在导电的基底上直接制备出镍基材料的纳米结构将具有十分重要的应用价值。论文采用水热的方法在基底上制备出了不同结构和形貌的镍基纳米材料薄膜,并且测试了它们的非酶的葡萄糖传感特性。利用葡萄糖在高温水热条件下的碳化制备出了氧化镍和部分石墨化碳的复合纳米片,并讨论了部分石墨化碳对葡萄糖传感器性能的影响。利用聚乙烯吡咯烷酮作为还原剂,制备了金属镍单质纳米颗粒的薄膜,并测试了其非酶的葡萄糖传感性能。具体研究工作如下：1.通过使用不同的沉淀剂、改变起始阳离子的浓度配比制备了镍基的水滑石粉体材料和纳米片薄膜,讨论了水滑石纳米片在基底上直接成膜的机理。(1)三种沉淀剂包括氨水、氢氧化钠和碳酸钠、尿素分别被用来制备镍铝水滑石。使用不同的沉淀剂制备出的粉样的形貌各不相同。(2)通过水热处理硝酸镍、硝酸铝和尿素的混合溶液,在钛片、铁钴镍合金、陶瓷、云母基底上直接制备出了镍铝水滑石的纳米片薄膜。水滑石纳米片在基底上的直接成膜得益于尿素的水解和基底的粗糙度。使用尿素作为沉淀剂时,相对温和的沉淀反应让镍铝水滑石的种晶可以粘附在基底上。而基底表面的粗糙度有助于降低种晶和基底之间的结合能。(3)通过改变起始反应溶液中的镍离子与铝离子的浓度配比,在钛片和陶瓷基底上制备了不同形貌的薄膜。2.将生长于钛片基底上的镍铝水滑石的纳米片薄膜用于了非酶的葡萄糖的探测。钛片基底在测试中显示出了较高的稳定性,没有参与镍铝水滑石对葡萄糖的电催化氧化。相对传统的涂抹法制备的镍铝水滑石粉末修饰的电极,直接生长在钛片基底上的镍铝水滑石纳米片薄膜在非酶的葡萄糖的探测中显示出了更高的灵敏度、更低的探测极限和更好的稳定性。这些改善得益于水滑石纳米片在金属基底表面的直接成膜。3.在基底上制备了氧化镍纳米丝、纳米片、氧化镍和碳复合纳米片薄膜,并比较了氧化镍纳米片和氧化镍/复合纳米片修饰的钛片的非酶的葡萄糖传感性能。(1)通过水热处理硝酸镍和尿素的混合溶液,在基底上制备出了纳米丝状的前驱体薄膜。退火后,得到了氧化镍纳米丝薄膜。通过水热处理硝酸镍、尿素和氟化铵的混合溶液,制备出了纳米片状的前驱体薄膜。退火后,得到了氧化镍纳米片薄膜。探讨了纳米片形成的机理以及氟化铵的用量对薄膜形貌的影响。(2)通过水热处理硝酸镍、尿素、氟化铵和葡萄糖的混合溶液,在钛片基底上制备出了复合前驱体的纳米片薄膜。在氮气中退火后,得到了氧化镍和部分石石墨化碳材料的复合纳米片薄膜,探讨了葡萄糖的用量对薄膜形貌的影响。(3)测试了氧化镍纳米片和氧化镍／碳复合纳米片薄膜修饰的钛片的非酶的葡萄糖传感性能。相比单纯的氧化镍纳米片,氧化镍和部分石墨化碳的复合纳米片显示出了更快的响应速度、更低的探测极限和更高的灵敏度。4.通过水热处理硝酸镍、尿素和聚乙烯吡咯烷酮的混合溶液,制备了前驱体的薄膜,在氮气中退火后,得到了金属镍单质纳米材料的薄膜。讨论了金属镍单质生成的机理,并测试了金属镍纳米颗粒薄膜修饰的钛片的非酶的葡萄糖传感特性。与基于镍铝水滑石、氧化镍的葡萄糖传感器相比,基于金属镍纳米材料的葡萄糖传感器显示出了更快的响应速度、更低的探测极限和更高的灵敏度。但是该传感器的稳定性还有待进一步加强。更多还原

【Abstract】 Glucose sensing is of great importance in the research fields of biotechnology, clinical diagnostics and food industry. Enzymatic glucose biosensors possess good selectivity and high sensitivity. However, the easy inactivation of enzyme and the difficulty of enzyme immobilization on electrode surface result in the complex preparation process, high cost and short life of enzymatic glucose sensor. Thus, nonenzymatic glucose sensors have attracted more attention. Previous reports demonstrated that Ni-based nanomaterials have been used to perform the nonenzymatic detection of glucose and exhibit good performance in terms of glucose sensing. However, the synthesis of sensing material and its immobilization on electrode surface are performed in two steps in the classical electrode modification. This preparation method was not simple and was not suitable for the direct formation of ordered nanostructure on electrodes surface. This drawback was not convenient for the applications of Ni-based nanomaterials in the nonenzymatic glucose sensing. Therefore, the direct fabrication of nanostructured Ni-based materials on conductive substrates is of great value.This thesis discusses the hydrothermal preparation of Ni-based nanomaterial films with different structures and morphologies on various substrates and investigates their nonenzymatic glucose sensing ability. Nickel oxide and partially graphitized carbon composite nanosheet is prepared by the carbonization of glucose in the hydrothermal reaction. The effects of partially graphitized carbon on the electrochemical performance of glucose sensor are also discussed. In addition, metallic nickel nanoparticle film is synthesized using polyvinyl pyrrolidone as reduction agent. The nonenzymatic glucose sensing ability of the prepared metallic nickel nanoparticle film is also investigated. The details are as follows:1. Powder samples and films of Ni-based LDH nanomaterials are prepared by varying the kind of precipitation agents and the molar ratio of raw materials. The mechanism of the direct formation of LDHs nanosheet film on substrates is discussed.(1) Three kinds of precipitation agents, including ammonia, sodium hydroxide and sodium carbonate, and urea, has been used to synthesize Ni-based LDHs under the same hydrothermal treatment. The morphologies of the prepared powder samples are different from each other using different precipitation agents.(2) The direct fabrication of Ni/Al-LDH nanosheet film on titanium foil, Fe-Co-Ni alloy substrate, ceramic wafer, and mica substrate has been performed through the hydrothermal reaction of the mixing solution containing nickel nitrate, aluminum nitrate, and urea. The direct formation of Ni/Al-LDH film on substrates can be attributed to the hydrolysis of urea and the roughness of substrates. Using urea as precipitation agent, the coprecipitation reaction is mild enough for the Ni/Al-LDH seeds to adhere on substrates. Roughness of substrates surface helps to reduce the binding energy between seeds and substrates.(3) Films with different morphologies are obtained on Ti foil and ceramic wafer substrates by varying the molar ratio of Ni2+ to Al3+ cation.2. The Ni/Al-LDH nanosheet film formed on Ti foil has been used to perform the nonenzymatic detection of glucose. Ti substrate exhibits good stability in the electrochemical measurements and will not be involved in the electrocatalytic oxidation of glucose. Compared to the Ni/Al-LDH powder modified electrode prepared by classical spin coating method, Ni/Al-LDH nanosheet film formed directly on Ti foil exhibits higher sensitivity, lower detection limit and better stability towards the nonenzymatic detection of glucose. These improvements are attributed to the direct formation of LDH nanosheet film on metal substrate.3. NiO nanowire film, NiO nanosheet film, and NiO and partially graphitized carbon composite nanosheet film are prepared on substrates. NiO nanosheet film and NiO/carbon composite nanosheet film modified Ti foil have been used to perform the nonenzymatic detection of glucose.(1) NiO nanowire film on various substrates is prepared by calcining the precursor, which is synthesized through the hydrothermal reaction of nickel nitrate and urea. NiO nanosheet film is prepared by calcining the precursor, which is synthesized through the hydrothermal reaction of nickel nitrate, urea and NH4F. The formation mechanism of nanosheet is discussed. The effect of the amount of NH4F on the film morphology is investigated in the contrast experiments.(2) NiO and partially graphitized carbon composite nanosheet film is prepared on Ti substrate by calcining the precursor in N2 gas, which is synthesized through the hydrothermal reaction of nickel nitrate, urea, NH4F and glucose. The effect of the amount of glucose on the film morphology is investigated in the contrast experiments.(3) NiO nanosheet film and NiO/carbon composite nanosheet film modified Ti foil have been used to perform the nonenzymatic detection of glucose. Compared to pure NiO nanosheet, nickel oxide and partially graphitized carbon composite nanosheet exhibits faster response speed, lower detection limit and higher sensitivity towards the detection of glucose.4. Metallic nickel nanoparticle film on Ti substrate is prepared by calcining the precursor in N2 gas, which is synthesized through the hydrothermal reaction of nickel nitrate, urea and polyvinyl pyrrolidone. The formation mechanism of metallic nickel is discussed and the nonenzymatic glucose sensing ability of the prepared metallic nickel nanoparticle film is also investigated. Compared to sensors based on Ni/Al-LDH and NiO, glucose sensor based on metallic nickel nanoparticles exhibits faster response speed, lower detection limit and higher sensitivity. However, its stability remains to be further improved.更多还原