Kuižová Alžbeta, Kuzminova Anna, Kylián Ondřej, Kočišová Eva
Faculty of Mathematics and Physics, Institute of Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague 8, Czech Republic.
Polymers (Basel). 2021 Nov 21;13(22):4023. doi: 10.3390/polym13224023.
Raman spectroscopy is one of the most used biodetection techniques. However, its usability is hampered in the case of low concentrated substances because of the weak intensity of the Raman signal. To overcome this limitation, the use of drop coating deposition Raman spectroscopy (DCDRS), in which the liquid samples are allowed to dry into well-defined patterns where the non-volatile solutes are highly concentrated, is appropriate. This significantly improves the Raman sensitivity when compared to the conventional Raman signal from solution/suspension. As DCDRS performance strongly depends on the wetting properties of substrates, we demonstrate here that the smooth hydrophobic plasma polymerized fluorocarbon films prepared by magnetron sputtering (contact angle 108°) are well-suited for the DCDRS detection of liposomes. Furthermore, it was proved that even better improvement of the Raman signal might be achieved if the plasma polymer surfaces are roughened. In this case, 100% higher intensities of Raman signal are observed in comparison with smooth fluorocarbon films. As it is shown, this effect, which has no influence on the profile of Raman spectra, is connected with the increased hydrophobicity of nanostructured fluorocarbon films. This results in the formation of dried liposomal deposits with smaller diameters and higher preconcentration of liposomes.
拉曼光谱是最常用的生物检测技术之一。然而，在低浓度物质的情况下，由于拉曼信号强度较弱，其可用性受到阻碍。为了克服这一限制，采用滴涂沉积拉曼光谱（DCDRS）是合适的，在这种方法中，液体样品被晾干形成明确的图案，其中非挥发性溶质高度浓缩。与来自溶液/悬浮液的传统拉曼信号相比，这显著提高了拉曼灵敏度。由于DCDRS的性能强烈依赖于基底的润湿性，我们在此证明，通过磁控溅射制备的光滑疏水等离子体聚合碳氟化合物薄膜（接触角108°）非常适合用于脂质体的DCDRS检测。此外，事实证明，如果使等离子体聚合物表面粗糙化，拉曼信号可能会得到更好的改善。在这种情况下，与光滑的碳氟化合物薄膜相比，观察到拉曼信号强度提高了100%。如图所示，这种对拉曼光谱轮廓没有影响的效应与纳米结构碳氟化合物薄膜疏水性的增加有关。这导致形成直径更小且脂质体预浓缩更高的干燥脂质体沉积物。
