Biochemical piezoresistive sensors based on pH- and glucose-sensitive hydrogels for medical applications

Ulrike Schmidt, Margarita Guenther, Gerald Gerlach
2016 Current Directions in Biomedical Engineering  
AbstractMany conventional analysis techniques to detect chemical or biological species are able to achieve a high detection sensitivity, however, they are equipment- or time-expensive due to a multi-step procedure. In this work we describe sensor concepts using piezoresistive pressure sensor chips with integrated analyte-sensitive hydrogels, that enable inexpensive and robust biochemical sensors which are miniaturizable and in-line capable. Biocompatible hydrogels were developed and tested for
more » ... ped and tested for pH- and glucose-monitoring during the chemical and biochemical processes. For that, monomer mixtures based on hydroxypropyl methacrylate HPMA, 2-(dimethylamino)ethyl methacrylate DMAEMA, tetraethylene glycol dimethacrylate TEGDMA and ethylene glycol EG were photo-polymerized. By means of carbodiimide chemistry, glucose oxidase was bound to the pH-sensitive HPMA/DMAEMA/TEGDMA/EG hydrogel squares causing the glucose-sensitivity. The crosslinked hydrogels were integrated in piezoresistive pressure sensors of different designs. pH- and glucose-depending reversible gel swelling processes were observed by means of the output voltage of dip sensors and of a novel implantable flexible sensor set-up. Due to its biocompatible components, the latter could be used inside the human body monitoring physiological blood values, for example glucose.
doi:10.1515/cdbme-2016-0029 fatcat:j7h3gshbtfgetar6giupdt6l7u