摘 要
生物传感器是一门由生物、化学、材料、电子技术和物理等多学科相互交叉形成的研究方向，其中基于新型纳米材料构建的电化学生物传感器由于其制备方法简单、灵敏度高、响应速度快和成本低等优点被广泛应用于食品、制药、环境监测、生物医学等方面。本文制备了几种新型纳米材料，并构建电化学生物传感器。具体内容包括以下三个方面：
（1） 采用电化学法还原氧化石墨烯，构建石墨烯修饰玻碳电极（GCE），选用方波伏安法（SWV）测定微量镉。实验研究了石墨烯修饰电极对镉的溶出伏安行为，优化了石墨烯用量、富集电位、富集时间、pH 值、支持电解质。结果表明石墨烯修饰电极明显增强了镉溶出信号，响应电流值与 Cd2+的浓度呈良好的线性关系，线性范围为0.001-1μg/mL,线性方程 y=27.8592x+0.3445 （R=0.998），检出限为 0.001 μg/mL,所制备的修饰电极重现性和重复性较好，6 次测定的相对标准偏差（RSD）分别为2.56%和2.51%.所提出的检测方法，简单、灵敏、快速，无需复杂的样品前处理，修饰电极可重复使用，能应用于实际水样中镉的快速测定。
（2） 采用葡萄糖作为还原剂，聚乙烯吡咯烷酮（PVP）为稳定剂制备一种新型绿色金纳米颗粒（AuNP），然后将金纳米颗粒修饰玻碳电极（AuNP/GCE），利用计时电流法对过氧化氢（H2O2）进行检测。实验优化了金纳米颗粒的用量、工作电位、磷酸缓冲溶液（PBS）的 pH 值。实验表明，所制备的 AuNP/GCE 对 H2O2有良好的电催化性能。线性范围为0.005-3.5 mM,最低检出限为 2.0 μM.此传感器制备方法简单，灵敏度高，检测线低，选择性好。
（3） 采用电化学还原氧化石墨烯法制备石墨烯，以 Cu2O 纳米颗粒为牺牲模板合成硫化铜空心球（CuSHNs），应用石墨烯/硫化铜空心球修饰玻碳电极，计时电流法测定过氧化氢（H2O2）。实验优化了石墨烯用量、还原时间、硫化铜空心球用量、磷酸缓冲溶液pH 值、工作电位。在优化条件下，响应电流值与 H2O2浓度在0.005-4.0 mM 范围内呈现良好的线性关系，线性方程为 y=7.1245x+0.3659 （R=0.9989），检测下限为 3.0 μM,3 次重复测定 RSD 为 2.46%.石墨烯与硫化铜空心球有良好的协同作用，显着提高了传感器对 H2O2响应电信号，所提出的检测方法具有简单、灵敏、快速等优点。
关键词：石墨烯；金纳米颗粒；硫化铜空心球；电化学传感器
Abstract
Biosensor is a multidisciplinary research filed involved biology, chemistry, materials,electronics and physics. Electrochemical biosensor based on functional nanomaterials hasmany advantages, such as simple fabrication, high sensitivity, fast response and low cost,which has broad application in many fields including food, pharmaceutical, environmentalmonitoring and biomedicine. The main contents of this paper focus on the preparation ofnovel functional nanomaterials, and its application in electrochemical biosensor. The specificworks are included as follows:
（1） An electrochemical sensor of Cd2+was constructed by electrochemical reduction ofgraphene oxide on the glassy carbon electrode （GCE）。 The determination of Cd2+wasproceeded by square wave voltammetry. The Stripping voltammetric behavior of Cd at thegraphene modified electrode was studied. The amount of graphene, deposition potential,deposition time, pH and the supporting electrolyte were optimized. In comparison with thebare glassy carbon electrode, the response signal of the graphene modified GCE wasobviously increased. Under the optimal conditions, the linear calibration curve ranges from0.001 to 1 μg/mL. The linear equation was y= 27.8592x+0.3445 （R=0.998）。 The detectionlimit was 0.001 μg/mL. The reproducibility and repeatability were also investigated with RSDof 2.56% （n=6） and 2.51% （n=6）， respectively. Owing to its simple fabrication, highsensitivity, fast response, good stability and repeatability, the developed sensor can serve aspromising electrochemical platform for the detection of Cd2+in real samples.
（2） We developed a novel strategy to synthesize gold nanoparticles （AuNP） by a greensynthetic method. The AuNP were synthesized by using glucose as the reducing agent andpolyvinylpyrrolidone as the stabilizing agent. AuNP is modified on the surface of glassycarbon electrode, and the modified electrode was applied to hydrogen peroxide （H2O2）detection by chronoamperometry. We optimized the amount of AuNP, the applied potentialand the pH of phosphate buffer solution for H2O2detection. AuNP exhibits excellentelectrocatalytic activity for H2O2reduction, such as an excellent sensing performance with awide linear range from 0.005 to 3.5 mM H2O2, and a low detection limit to 2.0 μM. Thedeveloped electrochemical biosensor based on AuNP possesses advantages such as simplefabrication, fast response, exellent selectivity and relatively low detection limit.
（3） Electrochemical reduction of graphene oxide was applied to prepare graphene.Copper sulfide hollow spheres were obtained using Cu2O nanoparticles as sacrificialtemplates. We fabricated an electrochemical biosensor for hydrogen peroxide （H2O2）detection with nanocomposites of the reduced graphene oxide and CuS hollow spheres bychronoamperometry. The amount of graphene, the reduction time of graphene oxide, theamount of CuS hollow spheres, the pH of phosphate buffer solution and the applied potentialwere optimized. Under the optimized experimental conditions, the response current versus theconcentration of H2O2is in a linear range of 0.005 to 4.0 mM and the detection limit is 3.0μM （S/N=3）。 The linear equation is y=7.1245x+0.3659 （R=0.9989）。 The reproducibility wasinvestigated with a RSD of 2.46% （n=3）。 The reduced graphene oxide and CuS hollowspheres have good synergistic effects, which can significantly enhance the amperometricresponse of the sensor toward H2O2. The developed H2O2sensor based on reduced grapheneoxide and CuS hollow spheres possesses advantages such as simple fabrication, fast response,good selectivity, wide linear range and low detection limit.
Keywords: reduced graphene oxide; gold nanoparticles; copper sulfide hollow spheres;electrochemical biosensor
目 录
第 1 章 绪论
1.1 电化学传感器
1.1.1 概述
1.1.2 电化学生物传感器
1.1.3 电化学无酶传感器
1.2 纳米材料在电化学传感器中的应用
1.2.1 纳米技术
1.2.2 纳米材料
1.2.3 碳纳米材料在电化学传感器方面的应用
1.2.4 金属纳米材料在电化学传感器方面的应用
1.2.5 半导体量子点在电化学传感器方面的应用
1.2.6 导电高分子在电化学传感器方面的应用
1.3 本论文的研究内容及研究意义
第 2 章 基于石墨烯的镉离子电化学传感器
2.1 引言
2.2 实验部分
2.2.1 仪器与试剂
2.2.2 氧化石墨烯的制备
2.2.3 传感器的制备
2.2.4 电化学测量
2.3 结果与讨论
2.3.1 石墨烯修饰电极形貌表征
2.3.2 石墨烯修饰电极的电化学特性
2.3.3 实验条件优化
2.3.4 传感器的分析性能
2.4 小结
第 3 章 绿色合成方法制备金纳米颗粒及应用于过氧化氢检测
3.1 引言
3.2 实验部分
3.2.1 仪器与试剂
3.2.2 绿色合成方法制备金纳米颗粒
3.2.3 传感器的制备
3.3 结果与讨论
3.3.1 金纳米颗粒的表征
3.3.2 AuNP 修饰电极的电化学特性
3.3.3 实验条件优化
3.3.4 传感器的分析性能
3.3.5 干扰实验
3.4 小结
第 4 章 基于石墨烯/硫化铜空心球过氧化氢电化学传感器
4.1 引言
4.2 实验部分
4.2.1 仪器和试剂
4.2.2 实验方法
4.3 结果与讨论
4.3.1 石墨烯、氧化亚铜模板和硫化铜空心球的形态表征
4.3.2 传感器的电化学性能
4.3.3 传感器的分析性能
4.4 小结
结论
参考文献
致谢
