A novel enzymeless electrochemical sensor based on Ni(OH)2–NiO(OH) nanoelectrocatalyst for sensitive and selective detection of uric acid in PBS simulated body fluid

Abstract

Neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and Huntington's disease are increasing worldwide. Therefore, the development of a low-cost, highly stable, and portable device for rapid and accurate risk assessment of relevant biomarkers, especially uric acid (UA), by electrochemical detection is currently attracting much attention. Herein, an electrochemical enzymeless UA sensor based on highly active Ni(OH)2–NiO(OH) nanoelectrocatalyst decorated on polyaniline–carbon nanotubes (PANI-CNTs) nanocomposite film, which was modified on a commercial screen-printed carbon electrode (SPCE) by electrodeposition method for sensitive and selective detection of UA. The sensing behavior of the modified electrode (named Ni(OH)2–NiO(OH)/PANI-CNTs/SPCE) is examined in a simulated body fluid (phosphate buffer solution-PBS, 0.01 M, pH 7.4) using differential pulse voltammetry (DPV) technique. The obtained results showed that the Ni(OH)2–NiO(OH)/PANI-CNTs/SPCE electrode exhibited outstanding electrocatalytic performance for the detection of UA at low potential (0.33 V vs. Ag/AgCl) without exhibiting interfering signals of dopamine (DA), glucose (Glu), ascorbic acid (AA) and urea. The sensor exhibited extra high sensitivity (386.8 μA mM−1 cm−2), high selectivity, good reproducibility, and durable stability with the ability to detect UA at both low (5–100 μM) and high (100–800 μM) levels with a very low detection limit down to 0.11 μM (individual detection of UA) and 0.29 μM (detection of UA in presence of DA) in a simulated body fluid. The recovery test using the proposed electrochemical sensor showed a high recovery percentage (>99.81 %), making it a viable option for practical applications.