Layered material platform for surface plasmon resonance biosensing

Abstract

Plasmonic biosensing has emerged as the most sensitive label-free technique to detect various molecular species in solutions and has already proved crucial in drug discovery, food safety and studies of bio-reactions. This technique relies on surface plasmon resonances in ~50 nm metallic films and the possibility to functionalize the surface of the metal in order to achieve selectivity. At the same time, most metals corrode in bio-solutions, which reduces the quality factor and darkness of plasmonic resonances and thus the sensitivity. Furthermore, functionalization itself might have a detrimental effect on the quality of the surface, also reducing sensitivity. Here we demonstrate that the use of graphene and other layered materials for passivation and functionalization broadens the range of metals which can be used for plasmonic biosensing and increases the sensitivity by 3-4 orders of magnitude, as it guarantees stability of a metal in liquid and preserves the plasmonic resonances under biofunctionalization. We use this approach to detect low molecular weight HT-2 toxins (crucial for food safety), achieving phase sensitivity~0.5 fg/mL, three orders of magnitude higher than previously reported. This proves that layered materials provide a new platform for surface plasmon resonance biosensing, paving the way for compact biosensors for point of care testing.

Aptamers for Detection and Diagnostics (ADD) is a proposed mobile app acquiring optical data from conjugated quantum nanodots to identify molecules indicating presence of SARS-CoV-2 virus: Why public health and healthcare need smartphone sensors as a platform for early detection and prevention

“…The R&D pillars in the process are as follows (a few may be pursued in parallel): , where a smaller K D (the ratio k OFF / k ON ) indicates greater binding affinity of the ligand for its target (SARS-CoV-2 target protein)], between aptamers and preferred target vs "nearest neighbor" protein competitor, based on shape and amino acid sequence (larger K D value indicate weaker binding), must show reproducible and statistically significant difference of at least one order of magnitude. The design of the binding assay remains to be determined but must include kinetic data using three different principles (surface plasmon resonance 376 , biolayer interferometry 377 and electrochemical impedance spectroscopy 378 ) to enable incisive data analysis.…”

Graphene Plasmonics in Sensor Applications: A Review

“…Other well-known types of graphene-based biological sensors comprise graphene integrated with metasurfaces [ 102 , 103 ] and plasmonic metal films [ 104 , 105 ]. The former devices are based on principles (ii) and (iii) outlined in the Introduction.…”

Multi-band MIM refractive index biosensor based on Ag-air grating with equivalent circuit and T-matrix methods in near-infrared region

“…Widespread applications such as food quality control, health, diseases diagnosis, and environmental and molecular monitoring make the biosensors a hot topic for researchers in these years [25][26][27] . The label-based and label-free sensors are two main types of biosensors.…”