基于多孔碳基纳米材料的全固态电位型传感器的研究
李敬慧
学位类型博士
导师秦伟
2016-05-30
学位授予单位中国科学院大学
学位授予地点北京
关键词多孔碳基纳米材料 固体接触层 固态离子选择性电极 电位型核酸适体传感器 Porous Carbon-based Nanomaterials Solid Contacts Solid-state Ion-selective Electrodes Potentiometric Aptasensors
摘要电位型传感器是电化学传感器的一个重要分支,由于其具有检测成本低廉、操作简单、响应快速等特点,在环境监测、临床分析和过程控制等领域已得到广泛应用。在电位型传感器领域,相比较于传统的内充液式离子选择性电极,全固态离子选择性电极具有易于小型化、无需特别保养、持久耐用等特点,被认为是新一代的离子选择性电极。但是,全固态离子选择性电极受离子选择性敏感膜与导电基体界面间电荷转移阻力、双电层电容和水层等因素的影响,其长期电位稳定性较差。此外,电位型传感器在实际应用中仍有一定的局限性,例如,全固态离子选择性电极的实用性以及电位型核酸适体传感器的灵敏度需要进一步提高。近年来,纳米材料由于其大的比表面积、高的导电性和强的疏水性已被用作固体接触层来改善全固态离子选择性电极的稳定性。然而,目前报道的纳米材料固体接触层存在制备繁琐、耗时、易发生团聚层叠等问题,影响了电极界面的比表面积、双电层电容和导电性等特性。基于此,本论文以提高现有全固态电位型传感器的稳定性、实用性以及灵敏度为出发点,发展了几种基于多孔碳基纳米材料的全固态电位型传感器。具体内容如下:
1.      基于双模孔C60的全固态聚合物膜铅离子选择性电极。
与原料C60相比,通过液液界面共沉淀法合成的双模孔结构C60具有更大的双电层电容、更快的电子转移能力和更高的疏水性能。基于双模孔C60这些优异特性,我们将电沉积的双模孔C60作为固体接触层发展了全固态聚合物膜铅离子选择性电极(Pb2+-ISE)。构建的Pb2+-ISE响应快速,响应时间为10-15 s,并且具有稳定的能斯特响应。线性范围为1.0×10-9 - 1.0×10-3 M,电极的检出限为5.0×10-10 M。此外,全固态聚合物膜Pb2+-ISE也表现出极好的电位稳定性,不受O2、CO2 和光干扰的影响,且在离子选择性敏感膜和双模孔C60固体接触层之间没有水层存在。我们进一步考察了所构建的Pb2+-ISE的可行性。结果显示基于双模孔C60的Pb2+-ISE能够作为很有效的检测手段对环境样品中的重金属离子进行检测。
2.      基于三维多孔石墨烯/介孔Pt纳米颗粒复合材料的全固态聚合物膜镉离子
选择性电极。
最近发展的具有相互交联网状结构的三维多孔石墨烯(3D PGR)不仅具有二维石墨烯的内在特性,还能为电子/离子、气体和液体的传输和存储提供了更多的“空间”。然而,3D PGR的孔直径能够达到几个微米,孔径过大限制其表面积增加。为了解决这个问题,我们以介孔Pt纳米颗粒(MPNs)作为交联位点,通过一步水热共组装法合成了孔径可调的三维多孔石墨烯/介孔Pt纳米颗粒(3D PGR-MPN)复合材料,并将其作为固体接触层发展全固态聚合物膜 Cd2+-ISE。所构建的Cd2+-ISE在线性范围1.0×10 -8-1.0×10 -4 M内具有很好的能斯特响应,其检出限达到1.5×10-9 M。此外,全固态Cd2+-ISE也显示出很好的长时间电位稳定性,不受O2、CO2 和光干扰的影响。由于PGR-MPN复合物本身的疏水性能,在聚合物膜和其下面的PGR-MPN复合物固体接触层之间并没有发现水层的存在。
3.      基于3D PGR-Pt复合材料的全固态聚合物膜铜离子选择性电极。
制备3D PGR及其复合材料所用到的水热还原方法反应过程需要高温,安全性差;此外,固体接触层通常使用滴涂的方法将其修饰至电极表面,操作冗长且耗时。因此亟需发展一种新的制备技术在电极表面修饰固体接触层。电化学沉积是一种快速、简便、低消耗以及易于控制的方法,可以用来在电极表面制备稳定的薄膜,而不需要任何进一步的处理。我们采用一步电化学沉积共还原GO以及H2PtCl4的方法,在金电极表面制得3D PGR-Pt复合材料。同时对3D PGR-Pt复合材料进行循环伏安以及阻抗电化学表征,结果表明3D PGR-Pt复合材料具有大的双电层电容以及快速的电子转移速率。基于此,我们将其作为固体接触层发展全固态聚合物膜铜离子选择性电极(Cu2+-ISE)。所构建的Cu2+-ISE在线性范围1.0×10-8-1.0×10-4 M内具有很好的能斯特响应,检出限达到7.9×10-9 M。计时电位测试表明 Cu2+-ISE同样具有很好的电位稳定性。
4.      基于3D PGR的全固态聚合物膜丝网印刷铜离子选择性电极。
常用的全固态聚合物膜离子选择性电极在测试时需要外接参比电极,不便于对重金属离子进行现场检测。丝网印刷电极(SPE)具有设计灵活,结构简单,一致性好,成本低廉,易于大规模生产等优点。此外,根据需要可以印刷成多电极体系,使电极高度集成,解决了以往在线监测过程中单电极体系不易操作的问题,提高了电极的实用性。我们利用恒电位还原的方法在双电极体系SPE表面直接还原GO制备3D PGR,并将其作为固体接触层发展全固态聚合物膜丝网印刷铜离子选择性电极(Cu2+-ISE)。所构建的Cu2+-ISE在线性范围1.0×10 -6-1.0×10 -3 M内具有很好的能斯特响应,检出限为3.9×10-7 M。由于PGR本身的疏水性能,在敏感膜和其下面PGR固体接触层之间无水层生成。此外,丝网印刷Cu2+-ISE同时含有工作电极以及参比电极双电极体系,使其能够满足现场检测的要求。
5.      基于石墨烯泡沫独立电极的全固态聚合物膜铜离子选择性电极。
通常情况下,大多数全固态聚合物膜离子选择性电极的制备需要两个步骤:(1)采用滴涂的方法或者电沉积的方法在基底电极表面制备固体接触层;(2)将离子敏感膜滴涂在固体接触层表面。这两个步骤使离子选择性电极的制备过程复杂。石墨烯泡沫(GF)由石墨烯片相互堆叠而成,具有互相连通的多孔网络结构,使其具有卓越的电子转移能力以及大的比较面积,使GF非常适合用作独立电极。基于此,本章中我们发展了基于石墨烯泡沫独立电极的全固态聚合物膜Cu2+-ISE。与常用的全固态离子选择性电极相比,石墨烯泡沫既作为电极基底材料又作为固体接触层,简化了电极的制作步骤,同时仍对目标离子具有很好的电位响应。构建的Cu2+-ISE在线性范围1.0×10 -9-1.0×10 -3 M内具有很好的能斯特响应,检出限能够达到2.5×10-9 M。此外,发展的单片电极对光、O2和CO2干扰具有很好的抗性,并且由于PGR本身的疏水性能,在离子敏感膜和其下面的固体接触层之间并无水层生成。
6.      基于多孔石墨烯的电位型核酸适体传感器检测啶虫脒。
除了对目标离子电位响应符合能斯特方程的离子选择性电极外,电位响应遵循不同模式的电位型核酸适体传感器同样受到研究者们越来越多的关注。在电位型核酸适体传感器中,受体直接与纳米材料相连而不是嵌入到敏感膜中。由于碳基纳米材料大的比表面积、强的亲和力以及好的生物相容性,核酸适体可以通过共价或者非共价的方式与其相连接。基于此,我们以核酸适体为识别分子、多孔石墨烯为换能材料,发展了一种检测烟碱类杀虫剂啶虫脒的电位型核酸适体传感器。核酸适体与目标分析物之间的特异性识别诱导核酸适体的构象发生一定的变化,从而导致电极电位的变化。结果显示,所构建的电位型核酸适体传感器对啶虫脒检测的线性范围为5×10-10 M-1.0×10-6 M,检出限为3×10-10 M,表明该传感器对啶虫脒具有很好的灵敏度,为其测试实际样品提供了可能。通过选择不同的核酸适体,本核酸适体传感器亦可对其它有机农药进行检测。
其他摘要Potentiometric sensors are one of the most importance research areas of electrochemical sensors. Due to their cost-effectiveness, rapid response, and simple operation, they have been widely employed in various fields, such as environmental monitoring, clinical analysis, and process control. Compared to conventional ion-selective electrodes (ISEs), all-solid-state ISEs are considered to be the new generation of ISEs. Note that all-solid-state ISEs are generally regarded as the future of potentiometric sensors, owing to their excellent properties, including easy miniaturization, convenient storage and maintenance, and durability. However, all-solid-state ISEs are influenced by the large charge-transfer resistance, the low double layer capacitance and the existence of the water layer at the interface between the ion-selective membrane and the electronic conductor, and the potential stabilities of all-solid-state ISEs are relatively poor. In addition, some deficiencies restrict the real applications of potentiometric sensors. For example, the practicability of the all-solid-state ISEs and the sensitivity of the potentiometric aptasensors should be improved. In recent years, nanomaterials have been used as the solid contact between the ion-selective membrane and the electronic conductor in all-solid-state ISEs in order to improve the potential stability due to their large surface area, excellent conductivity and good hydrophobicity. However, challenges still remain in the all-solid-state ISEs with nanomaterials as solid contact. The preparation of nanomaterials-based solid contact is complicated, time-consuming, and may cause aggregation,thus influencing the specific surface area, double layer capacitance, and conductivity at the electrode/membrane interface. In order to improve the stability, practicability and sensitivity of the all-solid-state potentiometric sensors, this dissertation develops several nanoporous carbons and uses them to design all-solid-state potentiometric sensors. The detailed contents are as follows:   
1.      All-solid-state polymeric membrane Pb2+-ISE with bimodal pore C60 as solid contact.
Compared with pristine C60, bimodal pore C60 synthesized by the liquid–liquid interfacial precipitation method has larger double layer capacitance, faster charge transfers and higher hydrophobicity. Based on its unique properties, we have developed an all-solid-state polymeric membrane Pb2+-ISE based on the electrodeposited bimodal pore C60 as solid contact. The proposed Pb2+-ISE exhibits a stable Nernstian response with a rapid response time of 10-15 s. The linear range is from 1.0×10-9 to 1.0×10-3 M with a detection limit of 5.0×10-10 M. Moreover, the all-solid-state polymeric membrane Pb2+-ISE also displays excellent potential stability, good resistance to O2, CO2 and light, and no water layer is existed between the ion-selective membrane and the underlying bimodal pore C60 solid contact. We further investigate the feasibility of the proposed Pb2+-ISE. The results show that the bimodal pore C60-based Pb2+-ISEs could be used as an effective detection tool for detecting heavy metals in environmental samples.
2.      An all-solid-state polymeric membrane Cd2+-ISE with three-dimensional porous graphene-mesoporous platinum nanoparticle (3D PGR-MPN) composite as solid contact.
Three-dimensional porous graphene (3D PGR) with interconnected networks have recently been developed, which not only possess the inherent properties of the two-dimensional graphene, but also provide much more “space” for the electron/ion, gas and liquid transportation or storage. However, the obtained pore dimensions in the framework of 3D PGR are up to several micrometers, which may restrict the surface area of the 3D PGR. In order to solve this problem, we have synthesized the 3D PGR-MPN composite with adjustable pore dimensions by applying MPNs as cross-linking sites through a one-step hydrothermal co-assembly method. The 3D PGR-MPN composite is used as solid contact for developing an all-solid-state polymeric membrane Cd2+-ISE. The proposed Cd2+-ISE exhibits a Nernstian response in the range from 1.0×10-8 to 1.0×10-4 M. The detection limit calculated as the intersection of the two slope lines is 1.5×10-9 M. Additionally, the developed electrode also exhibits good long-term stability and is robust to O2, CO2 and light interferences. Due to the hydrophobic characteristics of PGR-MPN composite, the presence of undesirable water layer between the polymeric membrane and the underlying PGR-MPN layer is not found.
3.      An all-solid-state polymeric membrane Cu2+-ISE based on the PGR-Pt composite as solid contact.
The hydrothermal reduction method used for the fabrication of 3D PGR and its composite always requires high temperatures. Additionally, the 3D PGR-based solid contact on the electrode surface is usually prepared by the drop-casting method, which is tedious and time-consuming. Therefore, it is necessary to develop a new fabrication technique to obtain a solid contact on the electrode. Electrochemical deposition is a rapid, facile, low cost and easily controllable approach to prepare a stable film on the surface of electrode without any further treatment. In this work, the 3D PGR-Pt composites can be prepared directly on the surface of gold electrodes by one-step electrochemical deposition co-reduction. The electrochemical properties of   the 3D PGR-Pt composite have been characterized by electrochemical impedance cyclic voltammetry and spectroscopy. The results indicate that the 3D PGR-Pt composite has large double layer capacitance and fast charge-transfer. We have developed an all-solid-state polymeric membrane Cu2+-ISE using 3D PGR-Pt composite as the solid contact. The proposed Cu2+-ISE shows a stable Nernstian response in the range from 1.0×10-8 to1.0×10-4 M. The detection limit calculated as the intersection of the two slope lines is 1.7×10-8 M. The results of chronopotentiometry indicate that the Cu2+-ISE has good potential stability.
4.      An all-solid-state polymeric membrane screen-printed Cu2+-ISE based on the 3D PGR as solid contact.
The commonly used all-solid-state ISEs require external reference electrodes, which may cause inconvenience for in-situ measurements. Screen-printed electrodes (SPEs) possess several advantages, such as flexible design, simple construction, good consistence, low cost, and ease to mass production. Additionally, SPEs can be screen-printed to the multiple-electrode systems for integration. The multiple-electrode systems resolve the operation difficulties of the single electrode system for the online monitoring processes, which can enhance the potential stability and reproducibility and further expand the application of the SPEs in the field of environmental analysis. We have developed a novel screen-printed Cu2+-ISE with a double-electrode system using 3D PGR as the solid contact prepared by constant potential reduction of the GO onto the surface of the SPE. The obtained Cu2+-ISE shows a stable Nernstian response in the range of 1.0×10-6-1.0×10-3 M. The detection limit calculated as the intersection of the two slope lines is 3.9×10-7 M. Due to the hydrophobic characteristics of PGR, no water layer between the sensing membrane and the underlying PGR solid contact is formed. Moreover, the screen-printed system is also composed of the solid-state reference electrode, which can satisfy the demand for in-situ analysis.
5.      An all-solid-state polymeric membrane Cu2+-ISE with graphene foam as a freestanding electrode.
Generally, the fabrication of an all-solid-state polymeric membrane ISE requires two steps: (1) solid contact layer formed on the substrate electrode surface is prepared by drop-casting or electrodeposition method, and (2) an ion-selective membrane is drop-casted on the top of the solid contact layer. Such steps are complicated. Graphene foam (GF) is composed of thin layers of stacked graphene sheets and possesses interconnected framework, which is essential for excellent electron transfer in the GF. The porous structures in the framework of the GF offer a large surface area, which has the potential to make the GF used as a freestanding electrode. We have developed an all-solid-state polymeric membrane Cu2+-ISE with graphene foam as a freestanding electrode. The GF is used as both electrode material and solid contact in the Cu2+-ISE, which simplifies the fabrication procedure compared with the conventional all-solid-state ISEs. The proposed Cu2+-ISE exhibits a Nernstian response in the range of 1.0×10-7-1.0×10-3 M. The detection limit calculated as the intersection of the two slope lines is 2.5×10-9 M. The developed electrode is also robust to light, O2, and CO2 interferences. Additionally, due to the hydrophobic characteristics of PGR, the undesirable water layer between the sensing membrane and the underlying solid contact is not found.
6.      Porous graphene-based potentiometric aptasensors for determination of acetamiprid. 
Unlike the ISEs that respond to the target ions following the Nernst equation, the potentiometric aptasensors based on a different response model have also attracted much attention. In the potentiometric aptasensors, the receptors are directly linked to the nanomaterial instead of being embedded into the polymeric membrane. Aptamers can be covalently or non-covalently attached to the carbon-based nanomaterials due to their large specific surface area, strong affinity, and good biocompatibility. In this work, we have developed a potentiometric aptasensor for detection of a nicotinamide insecticide acetamiprid. The porous graphene and aptamer are used as transducer layer and sensing layer of the aptasensor, respectively. The specific recognition event between the aptamer and the target analyte induces a conformational change in the aptamer, which combines the phosphodiester negative charges of the aptamer to the porous graphene, thus resulting in a potential change. Results show that the proposed aptasensor exhibits a good linear relationship to acetamiprid in the concentration range of 5×10-10 M-1.0×10-6 M and the detection limit is 3×10-10 M. The developed aptasensor has a good sensitivity to acetamiprid, providing a possibility for the determination of acetamiprid in real samples. This aptasening strategy can also be used to detect other organic pesticides using the different aptamers.
文献类型学位论文
条目标识符http://ir.yic.ac.cn/handle/133337/13837
专题中国科学院烟台海岸带研究所知识产出_学位论文
中国科学院海岸带环境过程与生态修复重点实验室_海岸带环境过程实验室
作者单位中国科学院烟台海岸带研究所
第一作者单位中国科学院烟台海岸带研究所
推荐引用方式
GB/T 7714
李敬慧. 基于多孔碳基纳米材料的全固态电位型传感器的研究[D]. 北京. 中国科学院大学,2016.
条目包含的文件
文件名称/大小 文献类型 版本类型 开放类型 使用许可
基于多孔碳基纳米材料的全固态电位型传感器(8536KB)学位论文 开放获取CC BY-NC-SA浏览 请求全文
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[李敬慧]的文章
百度学术
百度学术中相似的文章
[李敬慧]的文章
必应学术
必应学术中相似的文章
[李敬慧]的文章
相关权益政策
暂无数据
收藏/分享
文件名: 基于多孔碳基纳米材料的全固态电位型传感器的研究.pdf
格式: Adobe PDF
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。