Nanoparticles that can assemble and bind selectively on surfaces in intricate geometries can trigger multiple plasmonic modalities and enable wide applications in agriculture such as pesticide monitoring, in medical imaging such as targeted cancer detection, in bioengineering such as biotarget detection and biosensing, and in healthcare such as selection of drugs and their binding kinetics. However, these particles mainly rely on binding of the target to a surface to create a plasmonic resonance and subsequent shifts by binding of biotargets, which limit the flexibility to control overall sensitivity. Here, we present an unconventional way that sandwiches a virus (i.e., Hepatitis B virus: HBV) topographically between two or more nanoparticles on the top and the bottom to create a double-step shifting effect amplifying the total resonance wavelength shift on the surface by 1.53 - 1.77 times that significantly enhances the sensitivity. We successfully applied this approach to an intact HBV sensing application, which accurately quantified the viral load. This method establishes a new nanoparticle-based sandwiched nanoplasmonic approach to detect and quantify viral load using two-step sensing with broad applications in biosensing.

可以选择性地组装和结合在复杂几何形状的表面上的纳米粒子可以触发多种等离激元模态，并可以在农业中广泛应用，如农药监测，医学成像（如靶向癌症检测），生物工程（如生物靶标检测和生物传感）以及医疗保健等作为药物选择及其结合动力学。但是，这些颗粒主要依靠靶标与表面的结合来产生等离子体共振，并随后通过生物靶标的结合而发生位移，这限制了控制总体灵敏度的灵活性。在这里，我们提出了一种将病毒夹在中间的非常规方式（即，乙型肝炎病毒（HBV）在顶部和底部的两个或多个纳米粒子之间地形分布，以产生双步移动效果，将表面上的总共振波长移动放大了1.53-1.77倍，从而大大提高了灵敏度。我们成功地将此方法应用于完整的HBV感应应用程序，该应用程序可以准确地量化病毒载量。该方法建立了一种新的基于纳米颗粒的夹心纳米等离子体方法，该方法使用两步传感技术检测和量化病毒载量，在生物传感领域具有广泛的应用。