Infrared Plasmonic Biosensor for Real-Time and Label-Free Monitoring of Lipid Membranes

Abstract

In this work, we present an infrared plasmonic biosensor for chemical-specific detection and monitoring of biomimetic lipid membranes in a label-free and real-time fashion. Lipid membranes constitute the primary biological interface mediating cell signaling and interaction with drugs and pathogens. By exploiting the plasmonic field enhancement in the vicinity of engineered and surface-modified nanoantennas, the proposed biosensor is able to capture the vibrational fingerprints of lipid molecules and monitor in real time the formation kinetics of planar biomimetic membranes in aqueous environments. Furthermore, we show that this plasmonic biosensor features high-field enhancement extending over tens of nanometers away from the surface, matching the size of typical bioassays while preserving high sensitivity.

Periodic array-based substrates for surface-enhanced infrared spectroscopy

“…The authors also investigated the signal from thicker films in order to examine the spatial extent of the near-field enhancement and seemed to find a saturation for 40 nm-thick films. However, their data can also be interpreted to allow for a spatial extent of up to 100 nm, which would be in better agreement with newer findings [65,66]. This large nearfield extent is a consequence of the fact that the evanescent fields of the plasmons are less strongly bound to the surface in the infrared compared to the visible spectral range.…”

“…The contributions might, however, be smaller than the one derived in Figure 4, as nanoantennas concentrate the impinging electromagnetic energy, which means that the interaction far from the antenna might be smaller than without an antenna. On the other hand, the enhanced near-fields have much larger extension than in the visible spectral range [65,66].…”

“…[92] was employed by Limaj et al [65] and used as "an infrared plasmonic biosensor for chemical-specific detection and monitoring of biomimetic lipid membranes". Instead of only one linear nanoantenna array for the detection of amide bands, an additional array with nanoantennas tuned for the CH 2 -stretching vibrations was employed.…”

“…Limaj et al [65] investigated the spatial extension of the fields by increasing the thickness of a SiO 2 layer up to 100 nm. Even this far from the surface of the nanoantennas, an enhanced signal was clearly detectable, which agrees with the results gained 2 years earlier using layers of CBP [66] and with the results of FDTD simulations presented in Ref.…”

Attenuated Total Reflection Surface-Enhanced Infrared Absorption Spectroscopy: a Powerful Technique for Bioanalysis

“…This approach for tiny volume and small molecular amount is more favorable than studying a complex system due to the complexity we mentioned. Using resonant metal antennas may be a good choice to generate high EF [86][87][88][89]. Altug et al have used gold antenna array to study protein behavior both in air [86] and solution [87,88], depicting a promising future for antenna application in ATR-SEIRAS.…”