Details
Name
Helena Soares VasconcelosCluster
Networked Intelligent SystemsRole
Research AssistantSince
01st May 2017
Nationality
PortugalCentre
Applied PhotonicsContacts
+351220402301
helena.s.vasconcelos@inesctec.pt
2020
Authors
Viveiros, D; de Almeida, JMMM; Coelho, L; Vasconcelos, H; Maia, JM; Amorim, VA; Jorge, PAS; Marques, PVS;
Publication
Sensors
Abstract
2020
Authors
Vasconcelos, H; Almeida, JMMM; Saraiva, C; Viveiros, D; Jorge, PAS; Coelho, L;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
Biogenic amines, such as putrescine are potential indicators of food storage condition and deterioration. The real time measurement of their concentration in food may become an important method of food control. It was found that putrescine diffuses through a thin layer made from a solution of Poly(ethylene-co-vinyl acetate) (PEVA) and maleic anhydride. Poly(ethylene-co-vinyl acetate) is a common non-chlorinated vinyl capable to adsorb specific analytes as putrescine which upon diffusion, reversibly binds to the maleic anhydride causing the polymer swelling resulting in spectral changes from the optical point of view. Long Period Fiber Gratings coated with 30 nm titanium dioxide, a high refractive index material used to increase the intrinsic sensitivity to the external refractive index, were overcoated with a thin layer of maleic anhydride doped Poly(ethylene-co-vinyl acetate). When exposed to solutions containing small concentrations of putrescine the resonant band corresponding to the LP1,6 cladding mode was found to move to shorter wavelengths. The observed blue shift corresponds to the increasing concentration of putrescine in the fiber sensor structure. Further work is being carried out to improve the sensitivity and the limit of detection of the sensing system as well as to increase range of operation, which is presently limited to 0.3 to 0.5 M. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
2019
Authors
Viveiros, D; Almeida, JMMMd; Coelho, L; Vasconcelos, H; Amorim, VA; Maia, JM; Jorge, PAS;
Publication
Proceedings
Abstract
2019
Authors
Soares Guedes Vasconcelos, HCASG; Marques Martins de Almeida, JMMM; Teixeira Saraiva, CMT; da Silva Jorge, PAD; Costa Coelho, LCC;
Publication
Journal of Lightwave Technology
Abstract
2019
Authors
Vasconcelos, H; Almeida, JMMMd; Saraiva, C; Jorge, PAS; Coelho, L;
Publication
Proceedings
Abstract
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