Hybrid Dielectric-Graphene SERS Metasurfaces for Antibody Sensing

TL;DR

This paper introduces a hybrid dielectric-graphene SERS platform using silicon metasurfaces and functionalized graphene for sensitive, label-free detection of biomolecules like antibodies, with demonstrated molecular discrimination capabilities.

Contribution

The work presents a novel hybrid SERS sensor combining dielectric silicon metasurfaces with functionalized graphene for enhanced biomolecule detection.

Findings

Achieved label-free detection of antibodies at low laser power.

Validated molecular discrimination through strain and doping Raman analysis.

Demonstrated strong electromagnetic confinement with minimal heating.

Abstract

We present a hybrid surface-enhanced Raman spectroscopy (SERS) platform based on dielectric silicon metasurfaces integrated with functionalized graphene for the selective detection of biomolecules such as prolactin and SARS-CoV-2 antibodies. The metasurface comprises subwavelength silicon nanopillars that support Mie-type optical resonances, enabling strong electromagnetic field confinement with minimal heating and optical losses. Graphene monolayers are transferred onto the dielectric metasurface and functionalized using 1-pyrenebutanoic acid succinimidyl ester (PBASE), facilitating the selective immobilization of target antibodies via $\pi$-$\pi$ interactions and covalent bonding. Graphene transfer, functionalization, and analyte binding are confirmed by the SERS enhancement, which enables label-free detection at low laser power, avoiding photodamage and ensuring compatibility with sensitive biomolecules. Strain and doping analysis, performed through Raman vector decomposition, reveals distinct responses associated with each antibody, validating the sensor's capability for molecular discrimination.