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Hydrogel-Based Plasmonic Sensor Substrate for the Detection of Ethanol

Authors :
Christoph Kroh
Roland Wuchrer
Nadja Steinke
Margarita Guenther
Gerald Gerlach
Thomas Härtling
Source :
Sensors, Vol 19, Iss 6, p 1264 (2019)
Publication Year :
2019
Publisher :
MDPI AG, 2019.

Abstract

The in-line monitoring of ethanol concentration in liquids is a crucial part of process monitoring in breweries and distilleries. Current methods are based on infrared spectroscopy, which is time-consuming and costly, making these methods unaffordable for small and middle-sized companies. To overcome these problems, we presented a small, compact, and cost-effective sensing method for the ethanol content, based on a nanostructured, plasmonically active sensor substrate. The sensor substrate is coated with an ethanol-sensitive hydrogel, based on polyacrylamide and bisacrylamide, which induces a change in the refractive index of the substrate surface. The swelling and shrinking of such hydrogels offer a means to measure the ethanol content in liquids, which can be determined in a simple transmittance setup. In our study, we demonstrated the capability of the sensor principle for the detection of ethanol content ranging from 0 to 30 vol% ethanol. Furthermore, we determined the response time of the sensor substrate to be 5.2 min, which shows an improvement by a factor of four compared to other hydrogel-based sensing methods. Finally, initial results for the sensor’s lifetime are presented.

Details

Language :
English
ISSN :
14248220
Volume :
19
Issue :
6
Database :
Directory of Open Access Journals
Journal :
Sensors
Publication Type :
Academic Journal
Accession number :
edsdoj.fa577c617c374406b17af41742bcd0d3
Document Type :
article
Full Text :
https://doi.org/10.3390/s19061264