| Nanomaterials refer to the materials of which its small unit in the three-dimensional has at least one dimension in the size range of1nm～100nm, or materials use this as the basic unit structure. Due to their tiny size, nanomaterials possess unique physical and chemical properties those are different from the macroscopic materials composed of the same element, such as surface effect, micro-size effect, and quantum effect, macroscopic quantum tunneling effect and so on. So, nanomaterials have been a hot spot in fields of physical, chemical and materials science and so forth.Nano-materials have the higher specific surface area than conventional materials, so when applied to biosensors, it can provide lager enzyme attachment area, that means providing more reaction sites, thus increasing the amount of enzyme involved in the direct electrochemical reaction, this lead to the increase of the electronic signals, improve the sensitivity, selectivity and other properties of bio-enzyme sensor. It provides a broader prospect for the development of new biosensors.In this thesis, high conductive Te nanorods, CuS nano-flowers and Ag nano-dendrite were synthesized using different methods, respectively. They are all uniform in size and have good structural stability and excellent performance. The ion liquid modified carbon paste electrode (CILE) with good electrochemical performances was fabricated by using Ionic liquid (IL), hemoglobin, enzymes mixed together to form a uniform film on the surface of it. Among them, the room temperature ionic liquids is an important and indispensable part, it can promote the evenly dry of the mixture film, accelerate the transmission of electronic signals, and further improve the performance of biosensors.The main contents of the thesis are as follows:1. Te nanorods are prepared through water bath method. Hb electrochemical biosensors are fabricated by mixing Te nanorods, Hb and IL together to form a uniform film on the surface of the electrodes. The electrochemical test results of Hb-Te-IL modified electrode show that the high specific surface area of the nano-materials provide Hb more effective binding sites, the electronic signal transduction has been significantly improved. This modified electrode also shows good detection performance to the trichloroacetic acid (TCA), with the detection limit of0.104mmol/L. 2. The flower-like CuS nanomaterial (referred to as the CuS nanoflower) was synthesised in ethylene glycol (EG) by solvothermal method. CuS nanoflowers are mixed with Hb and IL, drop onto the surface of carbon paste electrode, and naturally drying to the formation of CuS-IL-Hb film based enzyme electrodes which are used in biosensors."Coffee ring effect" can be avoid in the process of drying due to the high viscosity of IL which promote the uniform distribution of Hb; IR and UV results show that the biological activity of the hemoglobin enzyme in the film are well maintained. The electrochemical test results show that the modified electrode has a good detection performance to the TCA with the detection limit of0.12mmol/L.3. Dendritic nanostructured Ag were prepared in cold water through replacement reaction with the main materials of silver nitrate and magnesium. The EDS results show the nanomaterial contain Ag element only; XRD results show the Ag crystal of the prepared nanomaterial; The SEM results show the branch crystal structure of the nanomaterial. The Hb-Ag-IL mixture film are modified on the surface of CILE which are obtained by mixing graphite powder, liquid paraffin and ionic liquid together. The mixture film is fixed to the CILE surface using the nafion embedding method. Dendritic nanostructured Ag with the high specific surface area and high conductivity significantly improve the electronic signal transduction. The electrochemical results show that this modified electrode has a good detection performance to the detection of H2O2with the detection limit of1μmol/L. |
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