Construction And Application Of Novel Electrochemical Sensors Based On Nanoparticles

Recently, construction of high sensitive and selective electrochemical sensor by synthesis and development of new nanomaterials and nanocomposites, make full use of new technologies which was integrated by biology, electronics and medical, and the new development technology of the sensor, has already become one of active area of modern analytical chemistry. In this thesis, seven kinds of new electrochemical sensors based on carbon nanomaterials and metal nanomaterials were constructed and the electrochemical analytical methods for glucose, hydrogen peroxide (H2O2), Human chorionic gonadotropin (HCG) and Carcinoembryonic antigen (CEA) were established. These reseach are not only significant to enrich research content of the electrochemical sensor, but also can expanded the application range of nanomaterials. At the same time, might provide new ideas for the construction of high sensitive and selective electrochemical sensor. The thesis consisted of four chapters and the author's main contributions were summarized and presented as follows:1. Two kinds of new electrochemical non-enzymatic glucose sensor based on CuNPs/MWNTs and NiNPs-MWNTs nanohybrid films were fabricated, and then new methods for glucose detennination were established. The results showed that the two kinds of nanomaterials have good electro-catalyticoxidation of glucose. The sensor based on CuNPs/MWNTs displayed a linearly range from6.4×1O-7to2.0×10-3mol·L-1, the detection limit was1.9×10-7mol·L-1(signal/noise=3) and the sensitivity was193.5μA·mM-1·cm-2. Meanwhile, the sensor based on NiNPs-MWNTs displayed a linearly range from3.2x10"6to1.75×10-2mol·L-1, and the detection limit was8.9×10-7mol·L-1(signal/noise=3) and the sensitivity was67.19μA·mM*-1·cm-2. Compared with the CuNPs/MWNTs, one-step electrodeposition of Ni-MWNTs nanohybrid films had some advantages of simple preparation, a wider linearly range. 2. Three kind of hydrogen peroxide (H2O2) biosensor were fabricated based on MWNTs/PDDA-AuNPs, PdNPs/GR-CS and ZnSnNPs/MWNTs nanomaterial films. The results showed the voltammetric of the biosensors showed a pair of well-defined and quasi-reversible redox peaks of Hb and had good electrocatalytic activity towards H2O2. The linearly range of Hb/MWNTs/PDDA-AuNPs/ITO, Hb/PdNPs/GR-CS/GCE and Hb/ZnSnNPs/MWNTs/GCE towards H2O2were5.0×10-6～1.3×10-3mol·L-1,2.0×10-6～1.1×10-3mol·L-1and5×10-7～8.40×10-4mol·L-1, the detection limit were8.9×10-7mol·L-1,6.6×10-7mol·L-1and1.1×10-7mol·L-1, and the apparent Michaelis-Menten constant (KM) were8.2×10-4mol·L-1,1.6×10-5mol·L-1and3.8×10-4mol·L-1. The above studies indicated that Zn-SnNPs/MWNTs which were prepared by electrodeposition of ZnCl2and SnCl2in Ethaline ionic liquids had lower detection limit and the immobilized Hb in the PdNPs/GR-CS nanocomposite film modified electrode had a higher biological affinity to H2O2.3. One new electrochemical immunosensor for CEA assay was developed based on AuNPs and Azure I/MWNTs-Nf. It was found that the peak currents were proportional to the CEA concentrations in the range of0.1～40.0ng·mL-1, and the detection limit was0.03ng-mL-1, which calculated at signal/noise ratio of3. A novel label-free amperometric immunosensor for determination of HCG was developed by immobilizing HCG antibody with AuNPs-GR/Thi/MWNTs. It was found that the changes of the current response were proportional to the HCG concentration in the range of0.1～5.0mIU·mL-1, and the range of5～400mIU·mL-1, and the detection limit was0.04mIU·mL-1.