Surface-Enhanced Raman Spectroscopy for the Characterization of Blood Serum Samples of Chronic Kidney Disease by Using 100 kDa

The biochemical markers present in blood serum can be utilized for the early identification of diseases. Both low molecular weight fractions (LMWF) and high molecular weight fractions (HMWF) are present in blood serum. The HMWF proteins can suppress the LMWF proteins, which are the major disease biomarkers and are considered important for the diagnosis of the diseases. This problem was resolved in the current study by separating the HMWF using Amicon ultra 100 kDa filtration devices. The filtrate portions of chronic kidney disease (CKD) and healthy were analyzed by surface-enhanced Raman spectroscopy (SERS). The major differentiating SERS features at 681, 1025, 1169, 1250, 1359, and 1405 cm⁻¹ are observed due to LMWF, which can be considered as SERS biomarkers of the CKD disease. Moreover, chemometric techniques such as principal component analysis (PCA) and partial least square regression (PLSR) model are applied for qualitative and quantitative discrimination of these different SERS spectral groups. PCA was found helpful for qualitative analysis, and the PLSR model helped for the quantification of creatinine in CKD positive 100 kDa filtrate samples.