Gout is a form of arthritis characterized by buildup of uric acid in synovial fluid, which causes severe swelling and can harm joints, tendons, and other tissues. It affects approximately 4% of the United States population, or approximately 8.3 million people nationwide and is therefore a topic of epidemiologic consideration due to its prevalence. Gout is typically diagnosed via polarized microscopy of arthroscopically-aspirated synovial fluid, which is a costly, time-consuming, labor-intensive, and technically complex procedure, warranting a simpler and less complex method for diagnosis. Here, we propose and validate a colorimetric method which is based on the ability of uric acid to reduce silver nitrate. We also assessed how the colorimetric change can be accelerated by changing the concentration of silver nitrate or adding different silver catalysts, as well as develop a matrix bed for improved handling and ease of use. When translated to the clinic, this diagnostic method for gout will have the potential to increase diagnostic efficiency and accelerate patient care at the bedside.
Keywords: biomarkers; diagnostic; gout; monosodium urate crystals; point-of-care.