Published in:
Journal of Sensors and Sensor Systems, 7 (2018) 1, Seite 51-55
Language:
English
DOI:
10.5194/jsss-7-51-2018
ISSN:
2194-878X
Origination:
Footnote:
Description:
Abstract. The inline monitoring of parameters in aqueous liquids isfacing an increasing demand in many different application areas. Hydrogelswith pH-induced swelling and deswelling behavior offer a means to measure pHin such liquids. Here we investigate the optical interrogation of apH-sensitive hydrogel which can be applied in the physiological pH range.For this, a nanostructured gold substrate supporting surface plasmonoscillations is coated with a HPMA/DMAEMA/TEGDMA/EG hydrogel. The gel swellsin the pH range under investigation (here 4.5 to 6.5), and the resultingrefractive index changes subsequently lead to a spectral shift of theplasmon resonance of the gold nanostructure. The spectral resonance positionis determined from optical transmittance spectra of the sensor substrates,and the initial results for our hydrogel reported here indicate a nearlylinear dependence between the swelling state and the plasmon resonancewavelength.