Few-monolayers-thick van der Waals nanostructures (WS2, MoSe2 and graphene) engineered onto a plasmonic surface can enhance the phase-related Goos-Hänchen shift sensitivity to analyte presence. The detection limit is as low as 0.1 aM for bovine serum albumin protein (67 kDa) and 1 fM for biotin molecule (244 Da) with WS2/graphene/Au interface.
Observing a Goos-Hänchen (GH) shift of the incident light beam provides a simple and convenient method of detecting fast phase variations without the need for cumbersome direct phase measurements. Here, we show that few-monolayers-thick van der Waals structures (WS2, MoSe2 and graphene) nano-engineered onto a plasmonic surface can enhance the phase variation sensitivity to analyte presence, leading to more than 3 orders of magnitude increase in the Goos-Hänchen shift (ca. 886 mm/RIU for a WS2/graphene/Au multilayer). The detection limit is evaluated to be as low as 0.1 aM (6.7 pg/mL) for bovine serum albumin protein with molecular weight of 67 kDa and 1 fM (24.4 ng/mL) for biotin (244 Da) molecules.Zum Volltext