Peer-Reviewed Journal Details
Mandatory Fields
Mac Kenna, N;Calvert, P;Morrin, A
2015
January
The Analyst
Impedimetric transduction of swelling in pH-responsive hydrogels
Published
12 ()
Optional Fields
REVERSE IONTOPHORESIS FUNCTION IMPEDANCE SPECTROSCOPY GLUCOSE BIOSENSOR TEMPERATURE SENSORS CONCANAVALIN MICROSYSTEM COMPOSITES ELECTRODE
140
3003
3011
A pH-responsive hydrogel composed of an aliphatic diamine cross-linked with polyethylene glycol diglycidyl ether (PEGDGE) using a single, rapid polymerisation step has been used to detect glucose by entrapping glucose oxidase (GOx) within its cationic network. The swelling response of hydrogel disks on exposure to glucose were optimised through variation of factors including the cross-linking density of the network, GOx loading and the addition of catalase. Hydrogel-modified carbon cloth electrodes were also prepared and characterised using voltammetric and impedimetric techniques. Non-faradaic electrochemical impedance spectroscopy (EIS) and gravimetry were both employed to track the swelling response of the gels quantitatively. The clear potential of utilising impedance to transduce hydrogel swelling was demonstrated where a linear decrease in gel resistance (Rgel) corresponding to the swelling response was observed in the range 1 to 100 mu M. A dramatic increase in the limit of detection of six orders of magnitude over the gravimetric measurement was achieved (from 0.33 mM to 0.08 mu M). This increased sensitivity, coupled with the textile-based electrode substrate approach opens the potential applicability of this system for monitoring glucose concentration via the skin by sweat or interstitial fluid (ISF).
CAMBRIDGE
0003-2654
10.1039/c4an02252a
Grant Details