Label-free detection of plasma using surface-enhanced Raman spectroscopy for bladder cancer screening

Abstract

At present, bladder cancer has become a common malignant tumor around the world, and the number of deaths from bladder cancer is also increasing year by year. Therefore, it is necessary to develop a powerful technology for further analysis. In this paper, we used a new method of surface enhanced Raman spectroscopy (SERS) to detect the plasma of 10 normal volunteers and 10 patients with bladder cancer, and successfully recorded their spectra. At the same time, the plasma of normal persons and patients was analyzed by difference spectrum analysis, principal component analysis(PCA), linear discriminant analysis(LDA) algorithm, and receiver operating characteristic (ROC) curves. The difference spectrum analysis shows that there are slight but significant differences in the spectra between normal plasma and bladder cancer plasma, which may indicate that some changes have taken place in the contents of protein, nucleic acid and lipid in patients with bladder cancer. PCA was used to investigate the correlation of multiple variables, so as to reduce the dimension, and combined with the LDA algorithm to distinguish normal samples and patient samples, the sensitivity and specificity are 80% and 100%, respectively. Finally, the area under the receiver operating characteristic（ROC） curve is 0.97, which further proves the validity of the diagnostic algorithm based on the PCA-LDA diagnostic algorithm. The exploratory work showed that the combination of SERS technology and PCA-LDA algorithm could distinguish the plasma of normal people and bladder cancer patients. And further showed that SERS could be used as a simple and effective method for the detection of clinical cancer.