This Master thesis provides a proof of concept for a novel, implantable continuous glucose sensing technology. Immobilized glucose oxidase in a poly 2-hydroxyethyl methacrylate hydrogel is used to enzymatically convert an increase in glucose level to a local decrease in pH, which leads to a swelling of the hydrogel. Encapsulated gold nanoparticles in the gel allow an optical readout of the glucose concentration. Experimental methods include hydrogel synthesis, nanoparticle encapsulation and finally glucose sensing with the hydrogel by UV-vis measurements. Two possible readouts, absorbance change and frequency shift, are discussed and tested. While a frequency shift is not detected, results show that the absorbance of the gel is proportional to glucose level, making it a promising concept for continuous glucose monitoring.