【作者】 汪晓霞；

【导师】 张海黔；

【作者基本信息】 南京航空航天大学 ， 应用化学， 2007， 硕士

【摘要】 近年来,金纳米材料因其独特的物理和化学性质,在生物传感器方面得到广泛地应用。本论文分别将金纳米颗粒和金纳米棒用于光学和电化学葡萄糖生物传感器进行研究。采用不同的酶固定方法制备了金纳米颗粒修饰的电流式葡萄糖生物传感器并对传感器的性能进行了研究。以直径为5 nm的金纳米颗粒作为“晶种”,葡萄糖氧化产物H2O2作为还原剂,氯金酸在晶种表面被还原,生成更多的金纳米颗粒,从而引起金纳米颗粒在可见光吸收峰强度的变化。这一变化与葡萄糖的浓度成正比,可以定量的检测葡萄糖浓度。根据这一原理制备了光学葡萄糖生物传感器。采用了三种不同的酶固定方法制备了金纳米颗粒修饰的电流式葡萄糖生物传感器并对其性能进行了研究。得到以下结论:物理吸附法具有操作简单、成本低、实用等优点,比较适合研究新材料对传感器性能的影响,但是传感器的线性范围较窄,抗干扰性较差;静电自组装法制备的传感器以铁氰化钾为电子媒介体对葡萄糖响应的线性范围宽,能够满足人体测试的需求,且有较小的米氏常数和较高的灵敏度,不足是响应时间较长,抗干扰性较差;化学吸附自组装法制备的传感器以二茂铁甲醛为电子媒介体对抗坏血酸的干扰有很好的抑制作用,响应快速且稳定性好,但是制备过程复杂,载酶量较小。另外用“晶种增长法”制备了金纳米棒,并将其用于电流式葡萄糖传感器进行研究。通过与无纳米材料修饰的和金纳米颗粒修饰的传感器进行比较,表明采用物理吸附法不能有效地提高生物传感器的性能。采用静电自组装法制备无金纳米颗粒和有金纳米颗粒修饰的葡萄糖传感器并对两者的性能进行比较,得出金纳米颗粒的存在大大提高了传感器的线性响应范围。更多还原

【Abstract】 In recent years, Au nanomaterials are wildly being used in the field of biosensor and expected to enhance the performances of biosensors because of their special physical and chemical properties. In this thesis, Au nanoparticles and nanorods were used in the fabrication of optical and amperometric glucose biosensors respectively. In the preparation of the glucose sensors, we have tried different enzyme immobilization methods and investigated their influences on the performances of the biosensors.The optical glucose biosensor was based on monitoring the light absorption of Au nanoparticles produced via reaction of AuCl4- with H2O2 generated from glucose oxidation. In this sensing system, Au nanoparticles with diameter of around 5 nm were used as "seeds", where Au ions were reduced and, as a result, the seeds grew in number, resulting in the changes of the absorbance of Au nanoparticle plasmon. As the concentration of glucose increased, the absorbance was intensified. This fact could be used for detection of glucose.Three different enzyme immobilization methods were applied in the preparation of amperometric glucose biosensors and the performances of the biosensors were investigated. From the experiment results, a few conclusions could be drawn. Firstly, physical adsorption method was suitable for investigating new materials applied in biosensors because of its easy preparation and low cost. However, the dynamical range was narrow and the selectivity was not good. Secondly, electrostatic self-assembly route, used in immobilization of glucose oxidase on the Au electrode, was a better methode for fabrication of glucose biosensor with a large linear range, small apparent Michaelis-Menten constant and high sensitivity, which could be confirmed by investing performance of biosensor in the presence of artificial redox mediator, potassium ferricyanide. But the response time and selectivity were not good enough. Thirdly, chemical adsorption self-assembly, used for fabrication of Au nanoparticle enhancing glucose biosensors, could result in a biosensor with advantages of suppressing the interference from ascorbic acid, being fast response and high stability. But the process of preparation was very complicated.Au nanorods were prepared by a seeding growth approach and were used in fabricating the nanorod-enhancing glucose biosensor. Comparison of the performances among the glucose biosensors showed that Au nanoparticle enhancing biosensor via electrostatic self-assembly method had a wider linear dynamical range.更多还原