Plasmonic Biosensing with Nano-Engineered Van der Waals Interfaces

Observing a Goos-Hanchen (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-Hanchen 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.

Automated summary

Observing the Goos-Hanchen shift of the incident light beam can detect fast phase variations without direct phase measurements. This study shows that nano-engineered van der Waals structures on a plasmonic surface can enhance the sensitivity of phase variation to analyte presence, leading to a significant increase in the Goos-Hanchen shift.