Quantifying glucose and lipid components in human serum by Raman spectroscopy and multivariate statistics

Abstract

Raman spectroscopy has been employed in the quantitative analysis of biochemical components in human serum. This study aimed to develop a spectral model to estimate the concentration of glucose and lipid fractions in human serum, thus evaluating the feasibility of Raman spectroscopy technique for diagnostic purposes. A total of 44 samples of blood serum were collected from volunteers submitted to routine blood biochemical assay analysis. The biochemical concentrations of glucose, triglycerides, cholesterol, and high-density and low-density lipoproteins (HDL and LDL) were obtained by colorimetric method. Serum samples (200 μL) were submitted to Raman spectroscopy (830 nm, 250 mW, 50-s accumulation). The spectra of sera present peaks related to the main constituents, particularly proteins and lipids. A quantitative model based on partial least squares (PLS) regression has been developed to estimate the concentration of these compounds, taking the biochemical concentrations assayed by the colorimetric method as sample's actual concentrations. The PLS model based on leave-one-out cross-validation approach estimated the concentration of triglycerides and cholesterol with r = 0.98 and 0.96, and root mean square error of 35.4 and 15.9 mg/dL, respectively. For the other biochemicals, the r was ranging from 0.75 to 0.86. These results evidenced the possibility of performing biochemical assay in blood serum samples by Raman spectroscopy and PLS regression and may be employed as a means of diagnosis in routine clinical analysis.

A high-throughput serum Raman spectroscopy platform and methodology for colorectal cancer diagnostics

“…12 Within the dry and liquid 785 nm spectra control intensities are higher in the C/C stretching bands (1447 cm −1 ), the shoulder of the phenylalanine band and higher peaks attributed to the Amide I region 1650-1660 cm −1 and the Amide III region between 1208 cm −1 and 1342 cm −1 . 18,29,30 The cancer spectra show higher levels in bands at 759 cm −1 and 853 cm −1 , attributed to tyrosine as well differences at 1127 cm −1 attributed to phospholipids and lipoproteins.…”

The use of FTIR and Raman spectroscopy in combination with chemometrics for analysis of biomolecules in biomedical fluids: A review

“…PLS could be used to predict glucose concentration in the range of 0-200 mg/dL. Using 10 latent variables (LVs), PLS showed high R 2 value (0.86) and lower RMSECV value (26.4 mg/dL) [58].…”

“…The R 2 values obtained from PLS regression were 0.96; 0.98; 0.75; and 0.86, while the RMSEC values were 15.9; 35.4; 17.8; and 24.2 mg/dL for cholesterol, triglyceride, HDL, and LDL respectively. Whereas the latent variables (LVs) used were 9 for cholesterol and 8 for triglyceride, HDL, and LDL, respectively [58].…”

Application of Raman spectroscopy in type 2 diabetes screening in blood using leucine and isoleucine amino-acids as biomarkers and in comparative anti-diabetic drugs efficacy studies

“…Most of them are optical based with Raman and infrared spectroscopy being prominent due to their potential for rapid, label-free, non-invasive and in-vivo diabetes screening applications. The conventional Raman spectroscopy where no special sample substrate is required has been used in measurement of glucose (sugar) concentration in blood where intensities of the characteristic spectral bands and spectral profiles are used in quantification and discrimination between diabetic and non-diabetic patients [ 3 , 4 , 6 , 10 ]. Prospects of the technique in in-vivo glucose measurements [ 4 ] and device miniaturization for diabetes screening [ 6 ] have also been reported.…”