Seyedi S, Parvin P, Jafargholi A, Abbasian A, Mehdinejad M, Khorrami A, Mehrabi M, Moafi A
Physics Department, Amirkabir University of Technology, Tehran 15875-4413, Iran.
Physics Department, Amirkabir University of Technology, Tehran 15875-4413, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 5;248:119237. doi: 10.1016/j.saa.2020.119237. Epub 2020 Nov 30.
In this work, the optical properties of Rhodamine B (RdB) are investigated in the attendance of various red blood cells (RBCs). RdB fluorophores, as biological markers, is excited using SHG-CW Nd:YAG laser at 532 nm. In fact, the addition of biomolecules of interest to the reference fluorophore notably changes the fluorescence properties of the suspension. Here, laser induced fluorescence (LIF) spectrophotometry based on Stern-Volmer quenching formalism and field emission scanning electron microscope (FESEM) are employed here. According to the given fluorescence spectra, the spectral shift of emissions as well as quenching coefficients are assessed subsequently. The Stern-Volmer formalism is used to determine the quenching coefficients. In fact, RdB + RBCs suspensions contain a plenty of bioconjugates leading to the signal reduction and notable red shift in RdB fluorescence emissions. Furthermore, it is demonstrated that the positive blood type RBCs exhibit the higher quenching coefficients and the larger red shifts against those of negative blood types. This mainly arises from the nature of specific sugar antigens available on the RBC membranes as to N-acetylgalactosamine and galactose attached to the O-antigen terminal would enhance further quenching of the species. Moreover, a significant correlation appears between Stern-Volmer coefficients and the corresponding RBCs. In fact, distinct discrepancy takes place in quenching coefficients in terms various positive/negative blood types to envisage a facile method of blood typing.
在这项工作中，研究了若丹明B（RdB）在各种红细胞（RBC）存在下的光学性质。RdB荧光团作为生物标记物，使用532 nm的SHG - CW Nd:YAG激光进行激发。实际上，向参考荧光团中添加感兴趣的生物分子会显著改变悬浮液的荧光性质。在此，采用基于斯特恩 - 沃尔默猝灭形式的激光诱导荧光（LIF）分光光度法和场发射扫描电子显微镜（FESEM）。根据给出的荧光光谱，随后评估发射光谱的位移以及猝灭系数。斯特恩 - 沃尔默形式用于确定猝灭系数。事实上，RdB + RBCs悬浮液含有大量生物共轭物，导致RdB荧光发射信号降低和显著的红移。此外，结果表明，与阴性血型的红细胞相比，阳性血型的红细胞表现出更高的猝灭系数和更大的红移。这主要源于红细胞膜上特定糖抗原的性质，因为附着在O抗原末端的N - 乙酰半乳糖胺和半乳糖会进一步增强该物种的猝灭。此外，斯特恩 - 沃尔默系数与相应的红细胞之间存在显著相关性。实际上，不同阳性/阴性血型的猝灭系数存在明显差异，从而设想出一种简便的血型鉴定方法。
