Synergistically Electrochemical Biosensors For Some Small Molecules Based On Some Novel Iron Cobalt Nickel Metal Nanocomposites

Cobalt hexacyanoferrate (CoHCF) has been widely applied in electrochemical field due to their interesting electrochemical properties such as ion-exchange properties, electrochromism, mixed-valence electrical conductivity, high catalytic activity, and good biocompatibility and so on. Nickel nanomaterial has been widely used in electrochemical biosensors due to good electrocatalytic activity to many bio-molecules. The synergistical effect original from preparation and design of composite of CoHCF, nickel nanomaterial with other materials has attracted widely interest.In this dissertation, the CoHCF porous films had been successfully electrodeposited on functionalized CNTs networks modified glassy carbon electrodes through a facile approach. The nickel nanoparticles-ionic liquid electrochemical binsesing platform was prepared enhanced by room temperature ionic liquid. Based on the two modified electrodes, a series of investigations were performed. The dissertation can be summarized as follows:(1) The CoHCF films had been successfully electrodeposited on functionalized CNTs modified glassy carbon electrodes by cyclic voltammetry. The modified electrodes were characterized by scanning electron microscope, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The sensor displayed an excellent electrocatalytic response to the reduction of hydrogen peroxide and the oxidation of vitamin B₂ (VB₂). The prepared electrochemical biosensor exhibited quick response time, broad linear range, and good sensitivity, and excellent stability. (2) The nickel nanoparticles-ionic liquid modified carbon paste electrodes (Ni_NP-IL/CPE) were prepared. The modified electrodes were characterized by scanning electron microscope and cyclic voltammetry. The electrochemical behavior of nickel nanoparticles could be enhanced by the ionic liquid which could accelerate the redox reaction of nickel in NaOH solution. The activation of Ni_NP-IL in alkaline media was used to form a Ni(OH)₂/NiO(OH)-IL film. The electrochemical behavior of dopamine (DA) and VB₂ at modified electrodes was investigated. The experimental conditions were optimized. Under the optimal conditions, the DA and VB₂ can be detection. The interference of ascorbic acid related to the determination of DA could be diminished efficiently. Based on the increased current of the electrocatalytic oxidation of glucose at the activated Ni_NP-IL/CPE in NaOH solution caused by addtion of AA, a novel detection strategy was constructed for the determination of AA.