| Owing to unique optic, electric, and magnetic properties, both gold and silver nanoparticles have been widely investigated and applied in the fields of medicine, chemistry, biology, environment, food, catalysis, and so on. In this dissertation, we study the application of gold and silver nanoparticles based on their localized surface plasmon resonance for the determination of medicine and small biomolecules. The main contents are as follows:(1) Colorimetric detection of cefazolin. The current analytical method of cefazolin is complicated in pharmacopoeia, and herein a simple and rapid colorimetric detection method is presented based on the interaction of cefazolin and gold nanoparticles (AuNPs). The aggregation of AuNPs resulting from the charge shielding effect of Na+ on the AuNPs could be prevented by cefazolin in a medium of high concentration of sodium chloride, making the AuNPs dispersed and displaying red colour. Therefore, the cefazolin can be detected according to the change of solution color from blue to red owing to the plasma resonance absorption of AuNPs. The absorbance ratio at 520/660 nm of AuNPs is in proportion to the concentration of cefazolin in the range of 0.1-5.0μmol/L with the detection limit of 14 nmol/L. With the present method, analysis of cefazolin sodium powder injection was made with the recovery of 97.4%～100.2% and the relative standard deviation lower than 6.1%.(2) Interaction betweent silver nanoparticles and adriamycin. A novel aldehyde-rich polysaccharide was prepared through the modification of dextran. Taking this aldehyde-rich dextran as stabilizer, silver nanoparticles with uniform size were successfully synthesized. Meanwhile, the interaction betweent this kind of silver nanoparticles and adriamycin was investigated by means of resonance light scattering technique. It was found that a linear relationship (lg (ΔILSPRS)=0.8744+0.7047 c) was obtained between the value of lg (ΔILSPRS) and the concentration of adriamycin in the range of 1.36×10-6～4.08×10-6mol/L with the relative coefficient (r) of 0.9689, and the corresponding determination limit was 1.30×10-7mol/L.(3) Detection of adenosine. Aptamer of adenosine is splitted into two fragments of ssDNA, which are attached to Ag@SiO2NPs and magnetic particles, respectively, and thus both of them could be linked in the presence of adenosine in the solution. Then, the formed Ag@SiO2NPs-MPs species can easily be removed from the solution in a magnetic field, and then the light scattering signal can be identified from Ag@SiO2NPs. Based on the change of scattetering signals, we can detect adenosine successfully. It was found that a linear relationship (ΔILS=666.50+505.18log c) was obtained between the value ofΔILS and the concentration of adenosine in the range of 5.0×10-4-8.0×10-6 mol/L with the relative coefficient (r) of 0.9818. Moreover, the present method can be used to detect adenosine, and there are not obvious effects of other nucleosides on the analysis of adenosine.
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