从理论上系统地研究了聚苯乙烯（PS）/Ag球壳阵列中银球壳的形状（球形和椭球形）和完整度（侧壁有无开口）对多阶窄线宽等离激元腔模式激发效率的影响。理论上发现，在完整的球形银壳层阵列中，基于电的等离激元腔模式（TM₂和TM₃）能够被高效激发，而基于磁的等离激元腔模式（TE₁）激发效率则非常低。通过单独地将银球壳改变为椭球形状或单独在银球壳侧壁赤道上对称构建6个小开口均能有效增大TE₁模式的激发效率。尤其是，存在一个最佳的开口（20?）可使得TE₁模式的激发效率达到最大。理论上进一步发现，TM₂、TE₁和TM₃等离激元腔模式在非完整（侧壁开口约为 20?）的椭球形银壳层阵列结构中均能够同时被高效激发。在实验上，利用自支撑技术成功地制备了侧壁带有开口（约为 20?）的椭球形银壳层阵列结构，实验测试的透射光谱与理论光谱非常吻合，很好地证实了理论预测结果的正确性。

Surface enhanced resonance Raman scattering (SERRS) is a physical phenomenon that occurs when the energy of incident light is close to that of electronic excitation of reporter molecules (RMs) attached on substrates. SERRS has showed great promise in healthcare applications such as tumor diagnosis, image-guided tumor surgery and real-time evaluation of therapeutic response due to its ultra-sensitivity, manipulating convenience and easy accessibility. As the most widely used organic near-infrared (NIR) fluorophore, heptamethine cyanines possess the electronic excitation energy that is close to the plasmon absorption energy of the gold nano-scaffolds, which results in the extraordinary enhancement of the SERRS signal. However, the effect of heptamethine cyanine structure and the gold nanoparticle morphology to the SERRS intensity are barely investigated. This work developed a series of SERRS nanoprobes in which two heptamethine cyanine derivatives (IR783 and IR780) were used as the RM and three gold nanoparticles (nanorod, nanosphere and nanostar) were used as the substrates. Interestingly, even though IR780 and IR783 possess very similar chemical structure, SERRS signal produced by IR780 was determined as 14 times higher than that of IR783 when the RM concentration was 6:5 × 10⁶ M. In contrast, less than 4.0 fold SERRS signal intensity increase was measured by changing the substrate morphologies. Above experimental results indicate that finely tuning the chemical structure of the heptamethine cyanine could be a feasible way to develop robust SERRS probes to visualize tumor or guide tumor resection with high sensitivity and target to background ratio.