Femtomolar Biodetection by a Compact Core-Shell 3D Chiral Metamaterial

TL;DR

This paper presents a compact 3D chiral metamaterial sensor capable of femtomolar detection of biomarkers like TDP-43 in complex environments, leveraging its chirality and enhanced sensing properties for biomedical diagnostics.

Contribution

The work introduces a novel core-shell 3D chiral metamaterial with high sensitivity and selectivity for biomarker detection, effective even in complex biological samples.

Findings

Sensitivity of about 800 nm/RIU and FOM of 1276 RIU-1

Detection of TDP-43 biomarker from 1 pM to 10 fM in serum

Effective operation in complex biological environments

Abstract

Highly sensitive and selective label free devices for real-time identification of specific biomarkers are expected to significantly impact the biosensing field. The ability of plasmonic systems to confine the light in nanometer volume and to manipulate it by tuning the size, shape and material features of the nanostructures, makes these systems promising candidates for biomedical devices. In this work we demonstrate the engineered sensing capabilities of a compact array of 3D metal dielectric core-shell chiral metamaterial. The intrinsic chirality of the nano-helices makes the system circular polarization dependent and unaffected by the background interferences, allowing to work even in complex environment. The core-shell architecture enhances the sensing properties of the chiral metamaterial on both in the far and near field, offering also a large surface to molecular immobilization. With our system we recorded sensitivity of about 800nm/RIU and FOM= 1276 RIU-1. The sensing abilities of the system is demonstrated with the detection of the of the TAR DNA-binding protein 43 (TDP-43) , a critical biomarker for the screening of neurodegenerative diseases. In particular, the sensor was tested in different environments, such as human serum, with concentrations ranging from 1pM down to 10fM, opening new perspectives for novel diagnostic tools.