Open AccessNear-infrared optical response of thin film pH-sensitive hydrogel coated on a gold nanocrescent array
Author(s) -
Hao Jiang,
Jan Markowski,
Jayshri Sabarinathan
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.021802
Subject(s) - materials science , surface plasmon resonance , refractive index , thin film , electron beam lithography , optics , surface plasmon , lithography , optoelectronics , plasmon , infrared , nanotechnology , resist , layer (electronics) , nanoparticle , physics
A hydrogel-based chemiresponsive sensor for monitoring H(+) (pH) has been developed by coating the surface of a gold nanocrescent array structure with a thin film of a poly(2-hydroxylethyl methacrylate)-based (poly-HEMA) hydrogel. The transmission measurement results of the close-packed gold nanocrescent array fabricated via electron beam lithography demonstrate near-infrared localized surface plasmon resonance peaks with sensitivities up to 332 nm/RIU in detecting refractive index change. Measurements of the hydrogel under solutions of increasing pH show the plasmon peak blueshifts by 17 nm and the integrated transmission increases by 1.8 in the operating range of 4.5 - 6.4 pH, which is ideal for biochemical sensor applications.