A simple uric acid assay by using 3‐hydroxytyramine as a chromogenic colorimetric sensor in human serum samples: Density functional theory supported mechanistic approach. Issue 4 (14th February 2023)

• Record Type: Journal Article
• Authors: Krishna, Honnur; Krishnegowda, Avinash; Anantharaman, Shivakumar; Ashwinee, Kumar Shrestha; Vijayalakshmi, A Edalli
• Is Part Of: Journal of the Chinese Chemical Society. Volume 70:Issue 4(2023)
• Page Start: 894
• Page End: 908
• Publication Date: 2023-02-14
• Subjects: clinical biomarker -- enzymatic -- oxidative coupling -- serum analysis -- uric acid; Chemistry -- Periodicals; Electronic journals; 540.5
• DOI: 10.1002/jccs.202200513
• Languages: English
• ISSNs: 0009-4536

Abstract

Abstract: A simple, fast, sensitive, convenient, and economical accurate enzymatic colorimetric sensor is developed for the quantification of the clinically important biomarker uric acid (UA) in human serum samples. The method is based on the quantification of UA using 3‐hydroxytyramine (3‐HT) as a chromogenic substrate by using peroxidase (POD) and uricase (UOx). UOx catalyzes the oxidation of UA where H2 O2 is generated in‐situ to produce allantoin and CO2 . The POD in oxidative coupling of peroxide in presence of 3‐HT, forms an intense orange‐colored product with λmax = 500 nm. The reaction was carried out in a citric acid‐tripotassium‐citrate buffer (12.5 mM) of pH = 6.8 at room temperature. Computational calculations were done by Gaussian‐16 employing the B3LYP functional basis set. The standard curve for UA was found to be linear between 12.3–297.3 and 3.07–396.5 μM by rate and fixed time method, respectively. The LOD and LOQ for UA were 1.5 and 2.9 μM, respectively. Within‐day and day‐to‐day precision was 1.50–3.07 and 3.10–4.16% ( n = 7), respectively. The accuracy ranges for UA concentrations of 24.7, 198 and 297.3 μM were 87%–101.50%, 90%–105%, and 89%–107%, respectively. The UA recovery range by the proposed method was 98.00%–100.47% with a mean recovery of 99.5% and has A good correlation coefficient of 0.981 with the standard method. Abstract : A rapid, sensitive, convenient and accurate assay method for the determination of clinically important biomarker uric acid (UA) in human serum samples has been developed. The analytical sensing signal is based on the oxidative addition of 3‐HT producing orange colored product. Density functional theory supported mechanistic approach for the colored product formation. The method has been validated thoroughly by various analytical steps.