The Application Of Silver Nanoparticles Decorated With β-cyclodextrin In Surface-enhanced Raman Spectroscopy

Silver nanoparticles are developed rapidly and broadly on account of theirwell-defined optical properties and widely used as the probe in surface-enhancedRaman spectroscopy (SERS). The silver nanoparticles decorated with β-cyclodextrin(β-CD-AgNPs) are different from the performance of classical silver nanospheres.Raman spectroscopy is one of the most powerful tools for qualitative analysis, whichcould provide abundant information of the structures base on the vibrational modes ofanalytes. SERS can provide significantly enhanced Raman signals of the analytemolecules, which have been specially adsorbed onto the roughened surfaces of metals,and obtain clearer information of the structures. SERS can not only be used as aqualitative tool, but also can be used to quantitatively analyze according to theintensity of characteristic peaks at the same time, giving an opportunity for thedevelopment of ultra-sensitive analytical methods. Using collioid nanoparticles assubstrates, some drugs were determined based on the SERS. The thesis mainlyincludes two parts: determination of6-mercaptopurine (6-MP) in tablets anddetermination of acriflavine hydrochloride (AH) in the pharmaceutical preparations.β-CD-AgNPs and classical silver nanospheres were used as SERS substratesrespectively to determine6-MP. In order to achieve the optimal SERS signals, theinfluence of some experimental conditions were examined and optimized. Under theoptimal conditions compared with classical silver nanospheres when β-CD-Agnanoparticles were used, the sensitivity was higher, the analytical time was shorter, andthe linear range was wider. This method was successfully applied to the determinationof6-MP in real samples and the results were satisfactory.β-CD-AgNPs were used as SERS active substrates to determine the AH. Thefabrication and characterization of the β-CD-AgNPs were described. Influence of thedosage of cyclodextrin, glucose and [Ag (NH3)2]+used in the synthesis, and experimental parameters, such as volume of CD-AgNPs solution, hydrochloric acidconcentration and mixing time for solutions of analytes were examined and optimized.Under the optimum conditions, the SERS intensity is proportional to the concentrationof AH in the range of1.1-110.0μg L-1. The corresponding correlation coefficient of thelinear equation is0.998. The limit of detection for AH is0.3μg/L. The recoveries ofthe AH in two kinds of injection are between79.5and89.3%and the RSDs arebetween1.3%to3.1%These results show that recoveries of AH and thereproducibility are satisfactory.