Label-Free Water Sensors Using Hybrid Polymer-Dielectric Mid-Infrared Optical Waveguides
Keywords
drop-cast coating; gradient refractive index; hybrid polymer-dielectric waveguides; label-free detection; mid-infrared absorption; sensor on-a-chip
Abstract
A chip-scale mid-IR water sensor was developed using silicon nitride (SiN) waveguides coated with poly(glycidyl methacrylate) (PGMA). The label-free detection was conducted at λ = 2.6-2.7 μm because this spectral region overlaps with the characteristic O-H stretch absorption while being transparent to PGMA and SiN. Through the design of a hybrid waveguide structure, we were able to tailor the mid-IR evanescent wave into the PGMA layer and the surrounding water and, consequently, to enhance the light-analyte interaction. A 7.6 times enhancement of sensitivity is experimentally demonstrated and explained by material integration engineering as well as waveguide mode analysis. Our sensor platform made by polymer-dielectric hybrids can be applied to other regions of the mid-IR spectrum to probe other analytes and can ultimately achieve a multispectral sensor on-a-chip.
Publication Date
6-3-2015
Publication Title
ACS Applied Materials and Interfaces
Volume
7
Issue
21
Number of Pages
11189-11194
Document Type
Article
Personal Identifier
scopus
DOI Link
https://doi.org/10.1021/acsami.5b01013
Copyright Status
Unknown
Socpus ID
84930628159 (Scopus)
Source API URL
https://api.elsevier.com/content/abstract/scopus_id/84930628159
STARS Citation
Lin, Pao Tai; Giammarco, James; Borodinov, Nikolay; Savchak, Mykhailo; and Singh, Vivek, "Label-Free Water Sensors Using Hybrid Polymer-Dielectric Mid-Infrared Optical Waveguides" (2015). Scopus Export 2015-2019. 232.
https://stars.library.ucf.edu/scopus2015/232