ABSTRACT
Raman imaging yields high specificity and sensitivity when compared to other imaging modalities, mainly due to its fingerprint signature. However, intrinsic Raman signals are weak, thus limiting medical applications of Raman imaging. By adsorbing Raman molecules onto specific nanostructures such as noble metals, Raman signals can be significantly enhanced, termed surface-enhanced Raman scattering (SERS). Recent years have witnessed great interest in the development of SERS nanoprobes for Raman imaging. Rationally designed SERS nanoprobes have greatly enhanced Raman signals by several orders of magnitude, thus showing great potential for biomedical applications. In this review we elaborate on recent progress in design strategies with emphasis on material properties, modifying factors, and structural parameters.
ABSTRACT
OBJECTIVE: To established a method for identification of different polymorphs of fluconazole by Raman spectra. METHODS: The analysis was performed by dispersive 780nm Raman system. Raman spectra of polymorphs A and B of fluconazole were obtained, and the result was verified by DSC, FTIR and Power X Ray Diffraction (PXRD). Without any pre-treatment, Raman analysis was directly carried on three different fluconazole solid oral products and the polymorphs A or B of fluconazole in the raw material was indicated by Raman spectra. The distribution of polymorphism contents was studied by Raman imaging technology. RESULTS: The characteristic Raman spectra of polymorphs A and B of fluconazole were obtained. And the polymorphisms of the three test products were determined. Sample T1 contained polymorph A and starch or dextrin as the main excipient. Sample T3 contained polymorph B and lactose as the main excipient. CONCLUSION: The polymorphs A and B of fluconazole in the raw material and solid oral products can be easily and quickly identified by Raman analysis.