Integrating Nanosensors into Macroporous Hydrogels for Implantation

Macroporous hydrogels are an attractive platform for implantable sensors because the network of interconnected macropores facilitates tissue integration. Embedded sensing elements, in our case, plasmonic gold nanoparticles, can transduce the presence, absence, and concentration of biochemical markers to the outside. We present here how to integrate such nanosensors into a macroporous hydrogel while preserving the nanosensor functionality in order to produce implantable sensors. We demonstrate that out of four different polymers, the poly(2-hydroxyethyl methacrylate-poly(ethylene glycole)diacrylate copolymer (pHEMA-PEGDA) results in a working sensor. Our approach of incorporating nanosized sensor elements into a hydrogel matrix generally identifies suitable polymers for implantable sensor systems.