Nickel ferrite modified nickel foam with enriched active sites for the efficient electrochemical sensing of uric acid

The escalating mortality rate attributed to patients suffering from hyperuricemia has urged the need for on-site monitoring of uric acid (UA) using a facile, rapid and highly sensitive detection system. Non-enzymatic electrochemical UA sensors have gained attention owing to its low cost and simplicity. Herein, we report combustion-derived MFe2O4 (M = Cu, Co, Ni, Zn) nanoparticle modified nickel foam (NF) based electrodes with large surface area as potential candidates for UA sensing application. The structure of the synthesized ferrites was confirmed through x-ray diffraction (XRD) while the morphology was investigated by field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) analysis. Among the four different ferrites, the broccoli like NiFe2O4 showcased better activity and a high sensitivity of 1.91 mA mM(-1) cm(-2) towards UA, capable of selectively detecting UA in the presence of various interferents. The Limit Of Detection (LOD) was found to be 8.45 mu M (S/N = 3) having a wide linear range of detection between 10.0 mu M and 5.0 mM. The developed biosensor showed good repeatability, reproducibility (n = 5) and was stable for <= 15 days with a minimal current reduction of 0.4 %. The sensing performance of NiFe2O4@NF electrode was further investigated by estimating the UA concentration in human blood serum samples and it was validated using clinically derived results and it is observed to have recovery rate of 94 % for UA concentration of similar to 10.0 mg/dL. Hence this work provides a simple strategy for designing NiFe2O4@NF electrodes for sensing UA in patients with hyperuricemia.