Plasmonic Nanodome Array for Point-of-care Medical Diagnostics

Charles J. Choi and Steve Semancik

Biomolecular Measurement Division

National Institute of Standards and Technology (NIST), USA

 

This presentation describes a label-free, photonics-based sensor system being developed to detect chemicals/metabolites in body fluids for medical diagnosis and intravenous (IV) drug monitoring.  Modalities demonstrated are surface-enhanced Raman scattering (SERS) for specific chemical identification and localized surface plasmon resonance (LSPR) for capture affinity biosensing, with both techniques configured for continuous analyses on fluid samples.  Simultaneous, high-performance SERS and LSPR measurements for a wide range of target analytes (drug compounds, metabolites, proteins) are enabled by incorporating plasmonic nanodome array structures into sample delivery tubing.  These metallic nanostructures, which produce large electric field enhancement, are fabricated using a high-fidelity, nanoreplica molding method.  To investigate potential applications in medical diagnostics and drug monitoring, SERS measurements on an IV-delivered pain medication (promethazine) and a common metabolite (urea) have been performed at physiologically relevant concentrations.