A cost-effective planar sensing platform exploiting localized surface plasmon resonance (LSPR) was developed. Borosilicate glass substrates were silanized with 3-mercaptopropyl-trimethoxysilane (MPTMS) to immobilize ~30 nm gold nanoparticles (AuNPs) produced via a seeded-growth method. The nanoparticle properties were characterized by absorbance spectroscopy, dynamic light scattering, ζ-potential measurements, and electron microscopy. Interrogation through a multi-mode fiber configuration revealed strong sensitivity to variations in the surrounding refractive index, with LSPR shifts exceeding 250 nm per refractive index unit. In addition, preliminary experiments on a flexible configuration based on a Poly(ethylene glycol diacrylate) (PEGDA) hydrogel embedding AuNPs demonstrate the potential extension of the platform toward conformable, wearable sensing interfaces. Overall, the results confirm that AuNPfunctionalized planar waveguides constitute a reproducible, compact, and adaptable architecture to be employed for biosensing applications.
Planar Optical Sensors Based on Localized Surface Plasmon Resonance: From Rigid to Flexible Devices
De Luca, Andrea;Esposito, Flavio;Campopiano, Stefania;Iadicicco, Agostino
2026-01-01
Abstract
A cost-effective planar sensing platform exploiting localized surface plasmon resonance (LSPR) was developed. Borosilicate glass substrates were silanized with 3-mercaptopropyl-trimethoxysilane (MPTMS) to immobilize ~30 nm gold nanoparticles (AuNPs) produced via a seeded-growth method. The nanoparticle properties were characterized by absorbance spectroscopy, dynamic light scattering, ζ-potential measurements, and electron microscopy. Interrogation through a multi-mode fiber configuration revealed strong sensitivity to variations in the surrounding refractive index, with LSPR shifts exceeding 250 nm per refractive index unit. In addition, preliminary experiments on a flexible configuration based on a Poly(ethylene glycol diacrylate) (PEGDA) hydrogel embedding AuNPs demonstrate the potential extension of the platform toward conformable, wearable sensing interfaces. Overall, the results confirm that AuNPfunctionalized planar waveguides constitute a reproducible, compact, and adaptable architecture to be employed for biosensing applications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
