Affordable, accessible biosensors for the diagnosis, management, and treatment of chronic diseases are critical to reducing healthcare costs. An often overlooked chronic condition that affects over 8 million Americans is gout. This condition is characterized by severe pain, and in more advanced cases, bone erosion and joint destruction. This thesis explores the fabrication and characterization of an optical, enzymatic uric acid biosensor for gout management, and the optimization of the biosensor response through the tuning of hydrogel matrix properties. Sensors were fabricated through the co-immobilization of oxygen-quenched phosphorescent probes with oxidoreductases within a biocompatible copolymer hydrogel matrix. Characterization of spectral properties and hydrogel swelling was conducted. In addition, evaluations of the sensitivity, repeatability, and long-term stability of the uric acid biosensor were conducted. The findings indicate that increased acrylamide concentration improved the biosensor response by yielding increased sensitivity and reduced lower limit of detection. However, the repeatability and stability tests highlighted some possible areas of improvement. Specifically, a consistent drift was observed in the response during repeatability testing, and a reduction in sensor response was seen after long-term storage tests. Overall, this study demonstrates the potential of an on-demand, patient-friendly gout management tool. This work also demonstrates an alternate use of the porphyrin-oxidoreductase biosensing platform and paves the way for a multi-analyte biosensor.
