Paper-based analytical device for analysis of uric acid in artificial urine

This research focuses on the study of a Microfluidic Paper-Based Analytical Device (µPAD) for analyzing uric acid in artificial urine samples. The color of the µPAD changes from green to purple upon detecting uric acid. In the experiment, a calibration curve showing the relationship between uric acid concentration and color intensity was established. The green intensity provided the best linearity, with the equation y = -0.7554x + 168.5 and an R² value of 0.9886. The calibration curve using green intensity was used to determine uric acid concentrations in the range of 25–125 ppm, with LOD and LOQ values of 14.88 ppm and 33.53 ppm, respectively. The developed method was applied to determine the uric acid concentration in artificial urine (AU) samples. The percentage recovery was 116.2%, and the precision (%RSD) was 3.14. Stability testing was conducted to compare the performance of µPADs with and without 0.01% w/v PEI, stored at 4°C and 25°C. The shelf life of µPADs containing 0.01% w/v PEI was 196 hours with 95% confidence in stability. The analysis of uric acid in urine samples demonstrated good accuracy and precision, making this method suitable for determining uric acid levels. This approach has the potential for real-world applications, including diagnostic screening for gout and kidney disease in human urine.