新型固相电致化学发光传感器的构建及其对环境污染物的检测

发布时间：2018-09-05 10:19

【摘要】：电致化学发光检测具有灵敏度高、线性范围较宽、分析速度快、仪器操作简单等突出优点,因此利用电致化学发光检测可以满足于环境中微量乃至痕量污染物的检测要求。但目前电致发光传感器主要集中单一材料从而造成发光信号不高,难以达到污染物浓度的检测范围;传感器不能够循环使用,造成资源浪费等。如何构建绿色、无污染、可循环使用、检测性能良好的电致化学发光传感器有着重要的意义。本论文以制备固定化的电致化学发光传感器为基础,构建了由纳米材料所组成的三种电致化学发光传感器,并利用这些固相传感器来进行快速灵敏地检测环境中的五氯苯酚以及重金属离子的含量。固定化的传感器可以重复利用,减少资源的浪费,并为检测环境污染物提供了新的方法。具体的研究工作分为以下几个方面:(1)构建了一个石墨烯-金纳米簇的新型固相电化学发光传感器,在共反应剂过硫酸根的存在下,基于五氯苯酚(PCP)与激发态的金纳米粒子发生氧化还原反应,从而通过淬灭的发光强度范围来检测环境中五氯苯酚的含量。在此体系中,石墨烯不仅可以增大金纳米簇的电致发光强度,还可为金纳米簇提供一个固定化的平台,从而解决了发光强度低和不能循环使用的问题。构建的固定化电致发光传感器具有非常好的选择性,在最优检测条件下,对五氯苯酚有着良好的线性范围(1.0×10-14 1.0×10-10 M)和超低的检测限(1.0×10-14 M)。本方法避免了复杂仪器的操作,具有低毒性,可循环使用,超高灵敏度检测等优点,为在实际水样中应急及在线检测PCP提供了一个简单易行、可供选择的分析检测方法。(2)利用电化学沉积的方法一步电沉积铂纳米簇-石墨烯复合材料于电极上,通过电致化学发光的方法,对铜离子进行快速、痕量检测。由于石墨烯的存在,相比单独的铂纳米簇,除了表现在电流强度增强、电致发光信号增大的方面外,其发光电位和循环伏安曲线出现的峰位置也出现前移现象。表明在此体系中石墨烯具有降低能垒,加速电子转移的能力。由于石墨烯和铂纳米簇层层沉积拥有较大的比表面积,使溶液中的铜离子容易吸附于修饰电极的表面,使得此传感器具有较高的灵敏度。该方法对铜离子的最低检测限为1.0×10-7 gL-1。(3)利用水热法制备硫化镉(CdS)纳米纤维,并将其用于铅离子的电致化学发光检测。为了降低纳米颗粒所引起的聚沉对体系检测所带来的影响,制备出的CdS纳米纤维能够有效防止聚沉并实现对铅离子的快速检测,其对铅离子的检测线性范围为1.0×10-10 1.0×10-6 gL-1,相关系数0.994。当信噪比S/N=3时,新型固相电致化学发光传感器的构建及其对环境污染物的检测检测限达到1.0×10-10 gL-1。因为纳米纤维不易发生聚集且具有较好的稳定性,使得此传感器具有高度稳定且重复性良好的电致化学发光性能。
[Abstract]:Electrochemiluminescence detection has many advantages, such as high sensitivity, wide linear range, fast analytical speed and simple instrument operation. Therefore, electrochemiluminescence detection can meet the requirements of trace and even trace pollutants in the environment. But at present the electroluminescent sensor is mainly concentrated on a single material resulting in a low luminescence signal which is difficult to reach the detection range of pollutant concentration; the sensor can not be recycled resulting in waste of resources and so on. How to construct a green, pollution-free, recyclable, and good detection performance of electrochemiluminescence sensors has important significance. Based on the fabrication of immobilized electrochemiluminescence sensors, three kinds of electrochemiluminescence sensors composed of nanomaterials were constructed in this paper. These solid state sensors were used for rapid and sensitive detection of PCP and heavy metal ions in the environment. The immobilized sensors can be reused to reduce the waste of resources and provide a new method for the detection of environmental pollutants. The specific research work can be divided into the following aspects: (1) A novel solid-phase electrochemiluminescence sensor was constructed for graphene gold nanoclusters in the presence of co-reaction agent persulfate. Based on the redox reaction of pentachlorophenol (PCP) with the excited gold nanoparticles, the content of PCP in the environment was determined by the range of luminescence intensity of quenching. In this system, graphene can not only increase the electroluminescent intensity of gold nanoclusters, but also provide an immobilized platform for gold nanoclusters, thus solving the problems of low luminescence intensity and no recycling. The immobilized electroluminescent sensor has very good selectivity. Under the optimal detection conditions, PCP has a good linear range (1.0 脳 10-14 渭 m) and an ultra-low detection limit (1.0 脳 10-14 M). The method avoids the operation of complex instruments and has the advantages of low toxicity, recyclable use, high sensitivity detection, etc. It provides a simple and easy way for emergency and on-line detection of PCP in real water samples. (2) Electrodeposited platinum nanoclusters-graphene composite materials on the electrode by electrochemical deposition. The copper ion was detected quickly and trace by electrochemiluminescence. Because of the existence of graphene, the peak position of the luminescence potential and cyclic voltammetry curve also appears forward shift in addition to the enhancement of the current intensity and the increase of the electroluminescent signal, compared with the single platinum nanoclusters. It is shown that graphene has the ability to reduce barrier and accelerate electron transfer in this system. Because graphene and platinum nanoclusters have a large specific surface area, copper ions in the solution are easily adsorbed on the surface of the modified electrode, which makes the sensor have high sensitivity. The minimum detection limit for copper ions is 1.0 脳 10 ~ (-7) gL-1. (3). Cadmium sulfide (CdS) nanofibers were prepared by hydrothermal method and used for the electrochemiluminescence detection of lead ions. In order to reduce the influence of precipitation caused by nanoparticles on the system detection, the prepared CdS nanofibers can effectively prevent the coalescence and realize the rapid detection of lead ions. The linear range for the detection of lead ions is 1.0 脳 10 ~ (-10) ~ (10) gL-1, 1.0 脳 10 ~ (-6) gL-1, correlation coefficient, 0.994. When S / N = 3, a novel solid-phase electrochemiluminescence sensor and its detection limit for environmental pollutants reach 1.0 脳 10 ~ (-10) gL-1.. Because the nanofibers are not easy to aggregate and have good stability, the sensor has a high stability and good reproducibility of electrochemiluminescence.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X830;O657.3

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