【作者】 吴雪梅；

【导师】 马士禹；

【作者基本信息】 华东师范大学 ， 物理化学， 2013， 硕士

【摘要】 近年来,贵金属纳米材料的制备和性能研究引起了许多学科的关注,如物理、化学、生物学和工程学等,这主要是因为他们与块状金属在机械、光学、磁学和电学等方面表现出完全不同的性质,这些不同的性质主要是由他们的尺寸效应引起的。在生物传感器、纳米生物等领域,研究贵金属纳米颗粒对葡萄糖氧化酶(GOD)活性的影响具有重要意义。本论文研究了贵金属(银,金)纳米颗粒的表面性质对GOD活性的影响。银纳米颗粒的表面性质对GOD活性影响的研究,采用壳聚糖作为载体,GOD作为酶模型,戊二醛溶液作为交联剂,用溶胶凝胶-交联法将不同覆盖度的GOD-AgNPs异质体固定在玻碳电极上,用二茂铁甲酸作为电子传递介质,采用循环伏安法测定电极的响应电流,从而得出酶电极的响应电流随葡萄糖浓度变化的规律。结果表明,覆盖度相同时,随着葡萄糖浓度的增大,异质体的响应电流增大；葡萄糖浓度相同时,覆盖度10%～80%GOD-AgNPs异质体的响应电流随覆盖度的增大而增大,80%-110%的GOD-AgNPs异质体,响应电流随覆盖度的增大而减小,但覆盖度为120%时响应电流却有所增强,即不同覆盖度的异质体的活性先增强后减弱再增强。覆盖度10%～120%的GOD-AgNPs异质体的响应电流值均小于同浓度的GOD的响应电流值,因此可推测,覆盖度低于120%时,AgNPs的存在会抑制GOD的活性。聚沉实验的现象为覆盖度从10%-60%异质体均完全聚沉,80%-120%出现紫外吸收峰。这一现象与电化学实验的结果相符合。利用酸性靛蓝法研究了不同大小金纳米颗粒的表面性质对葡萄糖氧化酶活性的影响。本文初步得出了利用酸性靛蓝法研究3OD-AuNPs异质体相对活性的实验方案。实验结果表明：随着覆盖度的增大,不同大小的AuNPs与GOD结合的异质体中GOD的相对活性总体上是增大的；覆盖度低于200%时,不同大小的AuNPs与GOD结合的异质体的相对活性均小于零,说明与AuNPs结合后抑制了GOD的活性；同一覆盖度时,随着AuNPs粒径的增大,相对活性值越小,即随着表面曲率的减小,GOD的活性越小,GOD活性的抑制程度越大。更多还原

【Abstract】 In recent years, study of preparation and properties of nanomaterials has attracted the attention of many branches of science, such as physics, chemistry, biology, and engineering. Interest in nanoparticles (NPs) arises from the fact that the mechanical, chemical, electrical, optical, and magnetic properties can be completely different from those of their bulk counterparts, and these differences are dependent on the particle size. The effect of noble metal nanoparticles on the bioactivity of glucose oxidase (GOD) is of great significance in biosensor, nano-biology and so on.This paper studied the influence of the precious metal (silver, gold) nanoparticles’surface properties on activity of glucose oxidase. The influence of silver nanoparticles’surface properties on activity of GOD used chitosan as the carrier, glucose oxidase as enzyme model, and glutaraldehyde as crosslinking agent. The sol gel-crosslinking method was used to fix the different coverage of GOD-AgNPs hybrids on the glassy carbon electrode, with ferrocene formic acid as electron transfer medium. Cyclic voltammetry measurement was used to detect the electrodes’ response current. The results showed that at the same coverage, GOD-AgNPs hybrids’ response current increased with the increase of the glucose concentration. At the same glucose concentration, the activity of the different coverage of GOD-AgNPs hybrids increased first, and then decreased, when the coverage was120%, it increased again, but the activity of the different coverage of GOD-AgNPs hybrids were all lower than those of the same concentration of GOD. When coverage was lower than120%, the presence of AgNPs may inhibit the activity of protein. Coagulation experiment phenomenon for coverage from10%to60%hybrids were completely coagulation,80%to120%hybrids appeared ultraviolet absorption peak. This phenomenon conformed to the results of electrochemical experiment.Acid indigo method was used to study the influence of different size of gold nanoparticles’ surface properties on activity of GOD. This article obtained the preliminary experiment scheme to study GOD-AuNPs hybrids’relative activity by using acid indigo method. According to the fish out of the experimental method, the relative activity of different coverage of GOD-AuNPs hybrids was calculated. The results showed that with the increase of the coverage, the relative activity of hybrids, which was formed by different sizes of AuNPs and GOD, increased totally. The number of hybrids’relative activity were negative (except200%hybrids), means that the presence of AuNPs may inhibit the activity of GOD. At the same coverage, with the increase of particle size, the negative number was bigger, that means with gold nanoparticles surface curvature decreased, the activity of GOD was smaller.更多还原