Gold-coated silver nanorods on side-polished singlemode optical fibers for remote sensing at optical telecommunication wavelengths

• Type: Article in International Scientific Journal
• Date: 2025

Authors

dos Santos, PSS (Author) Other; Mendes, JP (Author) Other; Pastoriza-Santos, I (Author) Other; Juste, JP (Author) Other; de Almeida, JMMM (Author) FCUP; Coelho, LCC (Author) FCUP

Journal

Title: Sensors and Actuators, B: Chemical

Vol. 425

ISSN: 0925-4005

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

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Other information

Authenticus ID: P-017-GJG

DOI: 10.1016/j.snb.2024.136936

Abstract (EN): The lower refractive index sensitivity (RIS) of plasmonic nanoparticles (NP) in comparison to their plasmonic thin films counterparts hindered their wide adoption for wavelength-based sensor designs, wasting the NP characteristic field locality. In this context, high aspect-ratio colloidal core-shell Ag@Au nanorods (NRs) are demonstrated to operate effectively at telecommunication wavelengths, showing RIS of 1720 nm/RIU at 1350 nm (O-band) and 2325 nm/RIU at 1550 nm (L-band), representing a five-fold improvement compared to similar Au NRs operating at equivalent wavelengths. Also, these NRs combine the superior optical performance of Ag with the Au chemical stability and biocompatibility. Next, using a side-polished optical fiber, we detected glyphosate, achieving a detection limit improvement from 724 to 85 mg/L by shifting from the O to the C/L optical bands. This work combines the significant scalability and cost-effective advantages of colloidal NPs with enhanced RIS, showing a promising approach suitable for both point-of-care and long-range sensing applications at superior performance than comparable thin film-based sensors in either environmental monitoring and other fields.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11