Plasmonic biosensors based on singular phase-enhanced lateral position shift for real-time detection of RGD-binding Integrins (Conference Presentation)

In this paper, we have designed and fabricated an atomically thin plasmonic sensing substrate based on two-dimensional phase change material Ge2Sb2Te5 and silver (Ag-GST). This substrate offers an ultra-low reflection in the SPR curves and a strong optical phase singularity. A custom-built SPR setup was developed here to directly measure the phase-singularity-induced lateral position shift. We have obtained a SPR sensitivity regarding the lateral position shift of 9.9577 x 10^7 μm/RIU, which is 3 orders of magnitudes higher than current position shift sensing scheme based on hyperbolic metamaterial. Due to the ultra-high SPR sensitivity, the binding processes between peptide and integrins directly from un-purified liposomes were real-time monitored. The concentrations of Mn2+ ions ranging from 1 fM to 1 mM on the binding dynamics have been systematically monitored with our developed phase-sensitive surface plasmon resonance biosensors.