Animal tissue-based chemiluminescence sensing of uric acid

A new flow injection analysis method based on animal tissue as recognition element for chemiluminescence sensing of uric acid is proposed in this paper. The liver of the large white pig was used as molecular recognition element. Uric acid is oxidized by oxygen under the catalysis of urate oxidase in the tissue column to produce hydrogen peroxide, which can react with luminol in the presence of potassium hexacyanoferrate(III) to generate a CL signal. The experimental results show that the CL emission intensity was linear with uric acid concentration in the range of 0.001-3 μg mL−1 and the detection limit (3σ) for uric acid was 4 × 10−4 μg mL−1. The biosensor detection system could be used continuously for 4 h with less than 10% decrease in the response. More than 200 measurements were carried out during this time. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of 4.47% for 1 μg mL−1 uric acid. The biosensor detection system has been applied successfully to the analysis of uric acid in plasma and urine samples.