Surface-Enhanced Raman Scattering of Whole Human Blood, Blood Plasma, and Red Blood Cells: Cellular Processes and Bioanalytical Sensing

Abstract

SERS spectra of whole human blood, blood plasma, and red blood cells on Au nanoparticle SiO 2 substrates excited at 785 nm have been observed. For the sample preparation procedure employed here, the SERS spectrum of whole blood arises from the blood plasma component only. This is in contrast to the normal Raman spectrum of whole blood excited at 785 nm and open to ambient air, which is exclusively due to the scattering of oxyhemoglobin. The SERS spectrum of whole blood shows a storage time dependence that is not evident in the non-SERS Raman spectrum of whole blood. Hypoxanthine, a product of purine degradation, dominates the SERS spectrum of blood after ∼10−20 h of storage at 8 °C. The corresponding SERS spectrum of plasma isolated from the stored blood shows the same temporal release of hypoxanthine. Thus, blood cellular components (red blood cells, white blood cells, and/or platelets) are releasing hypoxanthine into the plasma over this time interval. The SERS spectrum of red blood cells (RBCs) excited at 785 nm is reported for the first time and exhibits well-known heme group marker bands as well as other bands that may be attributed to cell membrane components or protein denaturation contributions. SERS, as well as normal Raman spectra, of oxy-and met-RBCs are reported and compared. These SERS results can have significant impact in the area of clinical diagnostics, blood supply management, and forensics.

Identification of Individual Exosome-Like Vesicles by Surface Enhanced Raman Spectroscopy

“…Biomolecular exosomal components were identified at 1123 cm -1 (lipids + proteins), 1172 cm -1 (proteins), 1307 cm -1 (proteins + lipids), 1366-1370 cm -1 (phospholipids + carbohydrates), 1445 cm -1 (lipids + proteins) and 1572-1576 cm -1 (nucleic acids). Interestingly, most of these pronounced peaks have previously been identified by others when recording Raman spectra of biological samples like erythrocytes [45] or even EVs (by classic Raman or SERS on bulk isolates). [18,19,32,33,36] Next, we could show that the generated spectra, in combination with a PLS-DA classification model, allow us to separate between vesicles derived from B16F10 melanoma cells and RBCderived vesicles.…”

Improved protocols for vibrational spectroscopic analysis of body fluids

“…Reported studies applied to blood serum [77] for the detection of gastric [78,79], colorectal [80], pancreatic [81] and naso-pharyngeal cancers [82] highlight the interest and potential of such approaches. However, the use of nano-particles or appropriate metallic based substrates [83] is required, and while the approach is promising, reproducibility in the data collected remains a challenge [84].…”

Raman Spectroscopy of Blood and Blood Components

“…205 Similar phenomena were reported in 2012, when Premarisi et al showed that the SERS spectrum of whole blood had a storage time-dependence that was not evident in the conventional Raman spectroscopy of whole blood. 50 Forensic Science. Raman spectroscopy of blood has not been solely concerned with the biochemical, biological, and medical domains, as it has also been developed as a forensic tool.…”

“…50 One of the co-authors of the latter study (McNaughton) was a member of the Monash group who were responsible for much of the earlier work on the oxygenation/deoxygenation cycle. The following year he was involved in another SERS study that characterized the interaction between nanoparticles and hemoglobin/RBCs, 51 and the year after that he co-authored work on hemoglobin's non-fundamental Raman modes; 52 enhanced overtones were observed in spectra of RBCs that, interestingly, were not found in hemoglobin solutions.…”

“…The results demonstrated that over a period of 24 h after sampling, the SERS spectrum of plasma became dominated by the signature of hypoxanthine, a well-known purine degradation product. 50 Despite the promising results obtained from SERS experiments on analytes in blood plasma, most were proof-of-principle and only demonstrated the possibility of detecting an analyte that was artificially spiked with the analyte. In 2014, a study on the shortcomings of SERS discussed the lack of published information on: (a) the effect of sample processing (e.g., filtration) and experimental parameters (e.g., excitation wavelength, metal colloid, etc.…”