Méjard Régis, Thierry Benjamin
Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, South Australia, Australia.
PLoS One. 2014 Oct 23;9(10):e107978. doi: 10.1371/journal.pone.0107978. eCollection 2014.
The objectives of this study were to establish an in-depth understanding of the signals induced by mammalian cells in surface plasmon resonance (SPR) sensing. To this end, two plasmonic structures with different propagation and penetration distances were used: conventional surface plasmon resonance and long-range surface plasmon resonance. Long-range SPR showed a lesser sensitivity to the absolute number of round cells but a greater resolution due to its very narrow spectral dip. The effect of cell spreading was also investigated and the resonance angle of long-range SPR was mostly insensitive unlike in the conventional SPR counterpart. Experimental data was compared with suitable models used in the SPR literature. Although these simple averaging models could be used to describe some of the experimental data, important deviations were observed which could be related to the fact that they do not take into consideration critical parameters such as plasmon scattering losses, which is particularly crucial in the case of long-range SPR structures. The comparison between conventional and long-range SPR for cellular schemes revealed important fundamental differences in their responses to the presence of cells, opening new horizons for SPR-based cell assays. From this study, long-range SPR is expected to be more sensitive towards both the detection of intracellular events resulting from biological stimulation and the detection of microorganisms captured from complex biological samples.
本研究的目的是深入了解哺乳动物细胞在表面等离子体共振（SPR）传感中所诱导的信号。为此，使用了两种具有不同传播和穿透距离的等离子体结构：传统表面等离子体共振和长程表面等离子体共振。长程SPR对圆形细胞的绝对数量敏感性较低，但由于其光谱凹陷非常窄，分辨率更高。还研究了细胞铺展的影响，与传统SPR不同，长程SPR的共振角大多不敏感。将实验数据与SPR文献中使用的合适模型进行了比较。尽管这些简单的平均模型可用于描述一些实验数据，但观察到了重要偏差，这可能与它们未考虑诸如等离子体散射损耗等关键参数有关，这在长程SPR结构的情况下尤为关键。传统SPR和长程SPR在细胞检测方案方面的比较揭示了它们对细胞存在的响应存在重要的基本差异，为基于SPR的细胞检测开辟了新视野。从这项研究来看，长程SPR有望对生物刺激引起的细胞内事件检测以及从复杂生物样品中捕获的微生物检测更加敏感。
