Preparation And Application Of Chemical Sensors Based On Carbon Nanomaterials

Carbon nanomaterials (CNMs) are among the most broadly discussed, researched and applied synthetic nanomaterials, specially, in the field of sensor. This is due to their diverse intrinsic electronic, mechanical and optical properties, chemical versatility and biocompatibility as well as their performance as a chemically robust platform. The artificial enzyme based on carbon nanomaterials has attracted more attention because of several advantages over natural enzymes such as long-term stability and easy storage. This thesis focuses on the exploring new functional materials based on carbon nanomaterials and the development of miniaturized, intelligent chemical sensors.(1) Preparation and application of single-walled carbon nanotube ensemble modified gold ultramicroelectrodesThis study describes a new and facile self-assembly method for fabricating SWNT ensemble modfied UMEs. In this method, bare gold UMEs were modfied with 1-(1-Pyrenyl)-1-methanethiol (PyMT) monolayer as an adhesion layer, followed by self-assembly deposition of SWNTs to obtain the SWNTs/PyMT/gold UMEs. The electrochemical properties, such as electrode reactivity and interfacial capacitance, of the fabricated SWNTs/PyMT/gold UMEs were investigated by using cyclic voltammetry. The fabricated SWNTs/PyMT/gold UME was used as a microscaffold exhibiting the SWNT properties for immobilization of organic redox dye methylene blue (MB) and glucose oxidase. The SWNTs/PyMT/gold UMEs are believed to be attractive for electrochemical microdevice studies and electroanalytical applications.(2) pH-Responsive electroactive thin films based on carboxylated multi-walled carbon nanotubes and Prussian blueThe combination of carboxylated multi-walled carbon nanotubes (CMWCNTs) and Prussian blue (PB) for fabricating pH-responsive electroactive composite thin films is reported. The as-prepared CMWCNT@PB composite films were found to change their electrochemical behaviors in response to the solution pH, including their cyclic voltammetric and the corresponding electrochromic behaviors. The electrochromic state of PB could be switched on and off by the solution pH. Furthermore, a linear relationship was found between the peak-to-peak potential separation of the cyclic voltammogram of PB and the solution pH, indicating that the composite film modified electrode might be useful for the development of novel pH sensors.(3) Preparation and application of reverse-bumpy-ball-type-nanoreactor-loaded nylon membranes as peroxidase-mimic membrane reactorsA reverse bumpy ball (RBB)-type-nanoreactor-based flexible peroxidase-mimic membrane reactors (MRs) was firstly fabricated. The RBB-type nanoreactors with gold nanoparticles embedded in the inner walls of carbon shells were loaded on nylon membranes through a facile filtration approach. The obtained catalytic films exhibited good catalytic activity towards 4-NP and offered the feasibility and ease of multiple reuse. The as-prepared flexible catalytic membrane as the peroxidase-mimic MR was studied. It was found that the obtained peroxidase-mimic MR could exhibit several advantages over natural enzymes, such as facile and good recyclability, long-term stability and easy storage. Moreover, the RBB NS-modified nylon MRs as a peroxidase mimic provide a colorimetric assay for H2O2.