UV-Resonance Raman spectroscopic investigation of human plasma for medical diagnosis

Superparamagnetic MoS2@Fe3O4 nanoflowers for rapid resonance-Raman scattering biodetection

Sensors for rapid and reliable detection of biomolecules are crucial for clinical medical diagnoses. Here, a rapid, ultra-sensitive, magnetic-assisted biosensor based on resonance Raman scattering at MoS2@Fe3O4 composite nanoflowers is presented. Raman shifts and X-ray photoelectron spectra indicated that the composite was formed via Fe-S covalent bonds. Convenient magnetic separations could be performed because of the superparamagnetic Fe3O4 nanoparticles. MoS2 E12g and A1g Raman peaks were used as probe signals for anti-interference immunoassays. The probe unit of the immunoassay also included goat anti-human IgG molecules that were used as the target analyte. Au substrates coupled with the goat anti-human IgG were used as capture units to form sandwich biosensors. Because of the magnetic enrichment, the detection limit was improved by three orders-of-magnitude and the detection time was reduced from 1.5 h to 1 min. Sandwich biosensors using MoS2@Fe3O4 nanoflowers as Raman probes could be very promising sensors for proteins, antigens, and other immunogenic biopolymers, as well as for corpuscular viruses and cells.

Plasma biomarkers of pulmonary hypertension identified by Fourier transform infrared spectroscopy and principal component analysis

The main goal of this study was to find specific plasma spectral markers associated with pulmonary arterial hypertension (PAH) induced by monocrotaline injection in rats. FTIR was used to monitor biochemical changes in plasma caused by PAH as compared with the systemic hypertension induced by partial ligation on the left artery and with the control group. Both pathologies, systemic and pulmonary hypertension, induced a unique response in the biochemical content of plasma, mainly related to the composition and secondary structure of plasma proteins. For PAH, β-pleated sheet components of plasma proteins were identified whereas the protein composition in systemic hypertension was dominated by unordered structures. In addition, a higher concentration of tyrosine-rich proteins was found in plasma in PAH than in systemic hypertension. The differences between both pathologies were identified also in terms of lipid composition/metabolism as well as in the content of RNA and glucose, suggesting that lipid peroxidation appears upon pulmonary hypertension development. In summary, this work demonstrates that FTIR spectroscopy supported by principal component analysis (PCA) has the potential to become a fast and non-destructive method for biochemical characterization of plasma that consequently could have a diagnostic significance in pulmonary hypertension.