Application of a near-infrared laser tweezers Raman spectroscopy system for label-free analysis and differentiation of diabetic red blood cells

Abstract

A home-made near-infrared laser tweezers Raman spectroscopy (LTRS) system was applied to detect hemoglobin variation in red blood cells (RBCs) from diabetes without exogenous labeling. Results showed significant spectral differences existed between the diabetic and normal RBCs, including the peaks dominated by protein components (e.g. 1003 cm) and heme groups (e.g. 753 cm) in RBCs, and accurate classification results for diabetes detection were obtained by linear discriminant analysis with 100% sensitivity (i.e. no false negatives in the study). This work indicated the great promise of LTRS as a label-free RBC analytical tool for improving the accurate detection of type II diabetes.

Optical Tweezers in Studies of Red Blood Cells

“…By combining OTs with Raman spectroscope, novel Raman tweezers have enabled the inelastic light scattering measurement from noninvasively fixed target cells one by one with great operation freedom and have shown wide potential in various biomedical and clinical applications. Specifically, diagnostic models for epithelial cancer [112], thalassemia (a hereditary hemolytic disease) [113,114] and type diabetes [115] based on identification and discrimination of single cells of pathological samples by Raman tweezers have been developed. In Raman tweezers, the trapping and Raman excitation wavelengths can be selected separately according to sample properties and excitation requirements [113], whereas in some applications, the trapping laser was utilized simultaneously as Raman excitation beam [115].…”

“…Specifically, diagnostic models for epithelial cancer [112], thalassemia (a hereditary hemolytic disease) [113,114] and type diabetes [115] based on identification and discrimination of single cells of pathological samples by Raman tweezers have been developed. In Raman tweezers, the trapping and Raman excitation wavelengths can be selected separately according to sample properties and excitation requirements [113], whereas in some applications, the trapping laser was utilized simultaneously as Raman excitation beam [115]. With Raman tweezers, the altered protein constitution and hemoglobin oxygenation in abnormal or diseased RBCs can be detected by the significant variations in Raman spectra of noninvasively optically trapped RBCs without exogenous markers, enabling Raman tweezers to be a promising, convenient and label-free tool for accurate monitoring of hemoglobin-related blood disorders, including type diabetes and α-and β-thalassemia [113][114][115].…”

“…In Raman tweezers, the trapping and Raman excitation wavelengths can be selected separately according to sample properties and excitation requirements [113], whereas in some applications, the trapping laser was utilized simultaneously as Raman excitation beam [115]. With Raman tweezers, the altered protein constitution and hemoglobin oxygenation in abnormal or diseased RBCs can be detected by the significant variations in Raman spectra of noninvasively optically trapped RBCs without exogenous markers, enabling Raman tweezers to be a promising, convenient and label-free tool for accurate monitoring of hemoglobin-related blood disorders, including type diabetes and α-and β-thalassemia [113][114][115]. As illustrated by Figure 6a, by scanning the equatorial plane of an RBC controlled by four optical traps through a Raman excitation probe (532 nm), the biomolecular characterization of single RBCs (i.e., hemoglobin distribution mapping) through recorded Raman spectra can be realized, and the healthy and thalassemic-RBCs can be noninvasively differentiated [113].…”

Single red blood cell analysis reveals elevated hemoglobin in poikilocytes

“…12 Micropipette aspiration has been employed to measure elongation. 13 Raman spectroscopy has been employed to analyze diabetic RBCs 14 and ABO blood typing. 15 These single-cell studies provide valuable information on RBC changes during poikilocytosis and other conditions.…”

Development of a flow cell based Raman spectroscopy technique to overcome photodegradation in human blood

“…The optical instrumentation and techniques employed for in vitro Raman blood analysis have been mainly based on laser tweezers Raman spectroscopy [12,13], surface enhanced Raman scattering (SERS) spectroscopy [14,15] and dried drop RS [3,16]. However, there can be potential challenges associated with these techniques such as: requirement for isolating the RBCs and long data acquisition times involved, in the case of laser tweezers-based optical trapping [5]; the lack of reproducibility of the Raman signal in SERS-based detection [17]; and sample inhomogeneity in the dried drop methods [18].…”