Development of a new fluorescent probe catalyzed by gold nanoparticles to determine the amount of uric acid in urine samples

Abstract

Introduction Uric acid is a metabolite of purine nucleotides. Uric acid is a strong reducing agent and one of the main antioxidants in plasma, Due to its low solubility in aqueous solution, it may accumulate in the human body. Abnormal level of uric acid in biological fluids of the body can indicate various diseases. Therefore, quick and reliable determination and measurement of uric acid in biological fluids is usually necessary for diagnosis and treatment.Aims:Our goal in this research is to develop a fluorescence probe catalyzed by gold nanoparticles to measure uric acid in urine samples.Method:Phosphate buffer reagents, fluorescein, and hydrogen peroxide were respectively added to a microtube containing standard uric acid in the urine medium, mixed thoroughly, and then gold nanoparticles were added and the volume was reached with deionized water. Finally, the solution was poured into a fluorescence cell and its fluorescence intensity was recorded at 520 nm.Results:In optimal conditions, a linear relationship (R2=0.9979) was established between uric acid concentration and response intensity in the range of 0.3-8.0 μg.mL-1. The detection limit for the proposed method was 0.12 μg.mL-1.Discussion and conclusion In the current work, a simple and valid fluorescence method based on fluorescein/hydrogen peroxide system catalyzed by gold nanoparticles was designed and validated to determine the amount of uric acid in urine samples, which is well able to measure uric acid in urine samples of healthy and patient individuals. This probe based on gold nanoparticles has advantages such as simplicity, fast response time and good reproducibility.