Open AccessEnhancement of side‐coupled surface plasmon resonance sensitivity by application of polymethylmethacrylate thin polymer films
Author(s) -
Amjad Saima,
Swargiary Kankan,
Somarapalli Manjunath,
Bora Tanujjal,
Hornyak Gabor L.,
Mohammed Waleed S.
Publication year - 2020
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2019.0656
Subject(s) - surface plasmon resonance , materials science , sensitivity (control systems) , optoelectronics , thin film , polymer , surface plasmon , plasmon , localized surface plasmon , nanotechnology , nanoparticle , composite material , electronic engineering , engineering
Here the theoretical and experimental investigation for enhancing surface plasmon resonance (SPR) sensitivity in a side‐coupled excitation system by the application of polymethylmethacrylate (PMMA) polymer thin films is presented. Proper selection of film materials, gold layer thicknesses d Au and SPR incident angle ( θ SPR ) resulted in the increased effective refractive index of the sensing region, and hence of the device sensitivity, and the dynamic detection range. This work demonstrates, by first‐order approximations, a characterisation scheme of SPR chips with unknown gold layer thickness d Au and uncertainty in SPR incident angle. The scheme utilised fitting theoretical calculations to measured SPR responses while varying d Au and θ SPR in equations. Device sensitivity nearly doubled following application of thin PMMA thin films on gold surfaces when sensing water‐chloroform mixtures as opposed to untreated surfaces that lacked a PMMA layer. The proposed work demonstrates a facilitative balance between theoretical expectations and experimental data to develop sensors for future applications.