The Research Of Optical Chemosensing And Electrochemical Sensing Based On Nanomaterials

Confronting with the Overarching and complex world, the popularization and application of chemical sensors has made the achieving, analyzing of figures or messages more hommization, facilitation, which offer us a sensory nerve to explore the mysterious science. No matter traditional enzyme electrodes or novel biochemical sensors, their outstanding properties such as accuracy and sensitivity, have always been the focus of multitudinous researchers. On the basis of the manufacturing methods of some mature chemical sensors, this thesis has finished optical or electrical chemical sensing aiming at two substances, using functionalized Ag and CNT nanomaterials. The whole process is based on the concept of safety and green environmental protection, pursuing convenient, simple instrument operation and a fast, accurate experiment result. The details work is as follows:1. The Synthesis of Ag Nanoparticles by Microwave-Assisted and its optical sensing of mercuric ionCombined the Gum acacia powder’s properties of reducibility, chelating with the high efficiency of Microwave-assisted technology, we quickly synthesized Ag nanoparticles (AgNPs) and detected Hg (Ⅰ, Ⅱ) ion by using its optical performance. In this chapter, the instrument of UV-Vis, XRD, and TEM had been used to look into the synthetic product’s morphology, structure and spectral property. The result was as follows:silver colloidal solution’s color was brownish yellow. The Ag nanoparticles in it had well crystallinity, and its UV-Vis absorbance peak was at 416 nm.In comparison with AgNPs produced at room temperature, our operation was speedy and time saving. The SPR peak of AgNPs was obvious. Next, we used the optical characteristics of AgNPs to test Hg(NO3)2, Hg2(NO3)2. When the concentration of Hg (Ⅰ, Ⅱ) ion increased, the colour of yellow silver colloidal solution changed and the intensity of absorbance peak decreased. At the same time, the position of peak had blue shift. Based on the linearity curve between the intensity of absorbance peak and the concentration of mercury ion at the wavelength of 416nm, we might judge approximately the content of Hg (Ⅰ, Ⅱ) ion in the solution. Its detection range was from 1.96×10-9 mol/ml to 1.96× 10-5 mol/ml. The selective experiment indicated that only the one added Hg (Ⅰ,Ⅱ) ion had changed in color and absorbance peak.2. An electrochemical sensor combined TUNEL for detection of apoptotic cellBased on the TUNEL method, we developed an electrochemical biosensor to research the apoptotic situation of K562 cells. In this chapter, we used CNT&PDA-FA as substrate material, adopted the efficient binding force between folic acid and folate receptor to fix K562 cells induced by simvastain on the electrode. EIS and fluorescence microscopy was applied to measure the adsorption amount of CNT&PDA-FA. Then we put the CdTe quantum dot which could produce electrochemical signal and detected by stripping voltammetry. When the apoptotic time was 8h and the concentration of apoptotic agent was 50nmol, we observed this method had excellent analysis capabilities and clear linear regularity (A=-35.1+(-15.7) logc, R=-0.9984). Its limit of detection was low to 50 cells.