Objective To investigate the characteristics of body fluid metabolic profile in patients with kidney stones based on surface-enhanced Raman spectroscopy,and to explore its application value and provide a reference for the screening of patients with kidney stones.Methods A total of 25 patients with kidney stones and 25 healthy controls were involved.Urine and blood samples were collected,whose spectra were measured with surface-enhanced Raman spectroscopy.The mean and difference spectra were plotted with origin software.The normalized data were processed with principal component analysis combined with linear discriminant analysis(PCA-LDA).Finally,the performance of the PCA-LDA method was evaluated with the receiver operating characteristic(ROC)curve.Results The levels of phosphatidylinositol,phenylalanine,palmitic acid/fatty acids,etc.in the urine of patients with kidney stones are higher than those in healthy controls,while the levels of components such as uracil and glycogen are lower.The content of methyl bands in the plasma of patients with kidney stones is higher than that of healthy controls,while the contents of glycogen,phosphatidylinositol,protein-tyrosine,phenylalanine,palmitic acid/fatty acid,hydroxyproline/tyrosine,and lipids are lower than those of healthy controls.Conclusion Surface-enhanced Raman spectroscopy can identify the changes in various metabolites in patients with kidney stones,and the combination of PCA-LDA and ROC analysis is helpful for the screening of patients.

Based on Ag nanoparticles as the surface-enhanced Raman spectroscopy (SERS)-active nanostructure, the SERS of uric acid was presented in the paper. The absorption spectroscopies of uric acid and the mixture of silver colloids and uric acid were measured. The possible enhancing mechanism of the uric acid on silver colloid was speculated. The characteristic SERS bands of uric acid were tentatively assigned. The influence of absorption time and different ion on the SERS of uric acid were also discussed. The SERS spectral intensity changes linearly with the uric acid concentration, which indicated that the SERS might provide a new kind of direct and fast detecting method for the detection of uric acid. The detection limit of uric acid in silver sol is found to be 1 mg/L.
Metal Nanoparticles ; chemistry ; Silver ; chemistry ; Spectrum Analysis, Raman ; methods ; Surface Properties ; Uric Acid ; analysis