Surface plasmons at a metal/dielectric interface resonate with incident light, generating an evanescent field at the interface, which is highly sensitive to the change in refractive index of the medium. These characteristics are utilized as the basis for surface plasmon resonance‐based sensors with Kretschmann configuration, providing label‐free and real‐time monitoring of binding interaction between probe and target moieties. Although graphene is recently extensively investigated in the field of optical sensors for the improvement of sensing performance, the proposed enhancement mechanisms in each study are ambiguous and inconsistent. Here, graphene‐deposited Au film as advanced plasmonic sensing substrates is reported. Work function measurements of Au–graphene with different number of layer and doping state explicitly corroborate the mechanism of sensitivity increase, confirming that the enhanced refractive index sensitivity originates from induced surface dipole due to the charge transfer between Au film and graphene. The best sensitivity is attained from two layers of graphene by a chemical vapor deposition method. Biotinylated bovine serum albumin and streptavidin are used to evaluate the biosensing performance.

中文翻译：

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通过调节石墨烯-金界面的电子密度来增强表面等离子体共振生物传感器的性能

金属/介电界面处的表面等离激元与入射光发生共振，在界面处产生generating逝场，该e逝场对介质的折射率变化高度敏感。这些特性被用作具有Kretschmann配置的基于表面等离振子共振的传感器的基础，提供了无标记的实时监测探针与靶标部分之间结合相互作用的方法。尽管最近在光学传感器领域中对石墨烯进行了广泛的研究以提高传感性能，但在每项研究中提出的增强机制尚不明确且不一致。此处报道了石墨烯沉积的Au膜作为高级等离激元传感基板。具有不同层数和掺杂状态的Au-石墨烯的功函数测量结果明确证实了感光度增加的机理，证实了增强的折射率感光度是由于Au膜与石墨烯之间的电荷转移而引起的诱导表面偶极子。通过化学气相沉积法从两层石墨烯获得最佳灵敏度。生物素化的牛血清白蛋白和链霉亲和素用于评估生物传感性能。