| Nanocomposites have developed into one of the most interesting research hotspots in electrochemical sensing due to their excellent optical,thermal,magnetic and catalytic properties.In this thesis,three gold nanocomposites were prepared,and then new electrochemical sensing methods based on three materials were established to detect nitrite（NO2-）and hydrazine（N2H4）.The theies can provide new ideas for electrochemical sensing research,and also expand the application scope of gold nanocomposites.Theies is divided into three chapters,the main innovations are as follows:1.Study of the electrochemical sensing method of nitrite based on Bi2MoO6@PDA-AuBi2MoO6@PDA-Au were synthesized and the sensing method for NO2-was established based on the material.SEM and TEM characterization revealed that Au NPs were highly dispersed deposition on the PDA-coated flower-like Bi2MoO6 surface.Electrochemical studies showed the method exhibited linear range of 0.25μmol·L-1-4.41 mmol·L-1,sensitivity of 73.90μA(mmol·L-1)-1cm-2,low detection limit of 0.08μmol·L-1.Compared with the related sensing methods,the linear range of the sensing method was broadened by one order of magnitude,and the detection limit was reduced by 1.1 times.2.Study of the electrochemical sensing method of hydrazine based on gold nanocomposites2.1 Au-ZnSnO3nanocomposites with Zn Sn O3 as hollow structure were prepared and an electrochemical sensing method of N2H4 was constructed.The results of SEM and TEM characterization showed that Zn Sn O3 displayed a regular hollow cube structure,while Au NPs were uniformly decorated with the average sizes of 20 nm on the surface and internal cavity of Zn Sn O3.Electrochemical studies showed that the N2H4 electrochemical sensing method had linear range of 0.020μmol·L-1-0.36 mmol·L-1,the sensitivity of 787.0μA(mmol·L-1)-1 cm-2,the low detection limit of 0.01μmol·L-1.Compared with similar sensing methods,the sensitivity of the method was improved 2 times and the linear range was broadened by 1.5 times of magnitude.2.2 Au-α-MnO2@δ-MnO2 nanocomposites were prepared and the N2H4 electrochemical sensing method based on the material was constructed.SEM and TEM results demonstrated that Au NPs with the diameter about 5 nm were dispersed evenly on the core-shell materialα-MnO2@δ-MnO2.Electrochemical experimental results showed that the N2H4 electrochemical sensing method had linear range of 0.0050μmol·L-1-0.56 mmol·L-1,sensitivity of 344.1μA(mmol·L-1)-1cm-2 and detection limit of 0.0050μmol·L-1.Compared with similar sensing methods,the linear range was broadened by one order of magnitude and the detection limit was decreased by 20 times.Compared with the method based on Au-Zn Sn O3 in the previous section,the linear range was broadened by one order of magnitude and the detection limit was decreased by 2 times. |
