Synthesis Of Carbon Nanocomposites And Its Application In Electrochemical Sensing

With the development of carban nanotechnology, Carbon nanomaterial showsirreplaceable role in human life and production activities. Carbon nanomaterialshaswidely used in constructing various electrochemical sensors due to its intriguingproperties such as high conductivity, high specific surface area and superiormechanical properties, which are good for binding nanomaterial and maintaining theircatalytic activity. Keeping the focuses on the synthesis of carbon nanocomposites andits application in electrochemical sensing, this dissertation includes the followingthree parts:1. A novel strategy for fabrication of a hydrogen peroxide sensor based onsilver nanoparticles electrodeposited on chitosan （CHIT）-graphene oxide （GO）nanocomposites modified cysteamine/Au electrode was reported. The CHIT-GOnanocomposites and the electrodeposited Ag NPs were characterized by atomic forcemicroscopy and scanning electron microscopy. The results showed the Ag NPsuniformLy dispersed on the CHIT-GO/cysteamine/Au electrode. The cyclicvoltammagrams and amperometric method were used to evaluate electrocatalyticproperties of the Ag NPs/CHIT-GO/cysteamine/Au electrode. The results showed thatthe as prepared electrode displayed good electrocatalytic activity to the reduction ofH₂O₂with a detection limit of0.7μM based on a signal-to-noise ratio of3. The sensorhas good reproducibility, wide linear range and long-term stability.2. A novel nitrite sensor was fabricated based on electrodepositedphosphotungsticacid PW₁₂O₄₀^3-（POMs） on chitosan （CHIT）-graphene （GS）nanocomposites modified cysteamine/gold （Au） electrode. The cyclic voltammagrams（CVs） and amperometric method were used to evaluate electrocatalytic properties ofthe POMs/CHIT-GS/cysteamine/Au electrode. The results showed that after POMswas electrodeposited on the CHIT-GS/cysteamine/Au electrode, a three-dimensionalporous structure formed and the electrochemical results showed that the3D porousfilm exhibited good electrocatalytic ability to the reduction of NO₂^-. Based on theelectrocatalysis a sensitive nitrite electrochemical sensor was constructed.3. A new glucose sensor was constructed based on Prussian blue （PB） modifiedcarboxylic group-functionalized carbon nanofibers （FCNFs） nanocomposites（PB–FCNFs）. The obtained PB–FCNFs nanocomposites showed a good catalysis toward the electrochemical reduction of H₂O₂, and an amperometric glucose biosensorwas developed by immobilizing glucose oxidase on the PB–FCNFs nanocompositesmodified electrode. The biosensor exhibited a rapid response, low detection limit,wide linear range, high sensitivity, as well as good stability, repeatability andselectivity. This nanocomposite could be used as a promising platform for theconstruction of other oxidase-based biosensors.