An Optical Device Based on a Chemical Chip and Surface Plasmon Platform for 2-Furaldehyde Detection in Insulating Oil

• Published in: Sensors (Basel, Switzerland) Switzerland), 2024-08, Vol.24 (16), p.5261
• Main Authors: De Maria, Letizia, Arcadio, Francesco, Gabetta, Giuseppe, Merli, Daniele, Alberti, Giancarla, Zeni, Luigi, Cennamo, Nunzio, Pesavento, Maria
• Format: Article
• Language: English
• Subjects: 2-Furaldehyde (2-FAL); molecularly imprinted polymer (MIP); oil–paper insulation monitoring; optical device; plastic optical fiber (POF); Sensors; surface plasmon resonance (SPR)
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s24165261

2-Furaldehyde (2-FAL) is one of the main by-products of the degradation of hemicellulose, which is the solid material of the oil-paper insulating system of oil-filled transformers. For this reason, it has been suggested as a marker of the degradation of the insulating system; sensing devices for 2-FAL analysis in a wide concentration range are of high interest in these systems. An optical sensor system is proposed; this consists of a chemical chip, able to capture 2-FAL from the insulating oil, coupled with a surface plasmon resonance (SPR) probe, both realized on multimode plastic optical fibers (POFs). The SPR platform exploits gold nanofilm or, alternatively, a double layer of gold and silicon oxide to modulate the sensor sensitivity. The capturing chip is always based on the same molecularly imprinted polymer (MIP) as a receptor specific for 2-FAL. The system with the SPR probe based on a gold nanolayer had a higher sensitivity and a lower detection limit of fractions of μg L . Instead, the SPR probe, based on a double layer (gold and silicon oxide), has a lower sensitivity with a worse detection limit, and it is suitable for the detection of 2-FAL at concentrations of 0.01-1 mg L .