Data from: Systematic study of the surface plasmon resonance signals generated by cells for sensors with different characteristic lengths

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.本研究旨在深入解析哺乳动物细胞在表面等离子体共振（Surface Plasmon Resonance，SPR）传感过程中诱导产生的信号。为此，本研究选用了两种具备不同传播与穿透距离的等离子体结构：传统表面等离子体共振结构与长程表面等离子体共振结构。长程SPR对悬浮圆形细胞的绝对数量敏感性较低，但因其光谱凹陷极窄，故而具备更高的分辨率。本研究同时探究了细胞铺展的影响：与传统SPR结构相比，长程SPR的共振角基本不受细胞铺展的影响。将实验数据与SPR领域文献中常用的适配模型进行了对比。尽管这类简单的平均模型可用于描述部分实验数据，但观测到了显著偏差——这是因为此类模型未纳入等离子体散射损耗等关键参数，而该参数在长程SPR结构的分析中尤为关键。针对细胞实验场景的传统SPR与长程SPR对比研究，揭示了二者对细胞存在的响应存在重要本质差异，为基于SPR的细胞检测分析开辟了全新方向。本研究结果表明，长程SPR在两类检测场景中均有望具备更高灵敏度：一是生物刺激引发的细胞内事件检测，二是从复杂生物样本中捕获的微生物检测。