Cobalt ferrite (CoFe2O4) nanoparticles (size: ∼10 nm) with high surface area for selective non-enzymatic detection of uric acid with excellent sensitivity and stability

Abstract

Non-enzymatic detection of uric acid (UA) with high selectivity and sensitivity is a challenging task for researchers working on biosensors. Little attention has been given to explore the surface area dependent sensitivity of cobalt ferrite (CoFe₂O₄) nanoparticles for non-enzymatic UA detection. Herein, we are reporting a CoFe₂O₄ nanoparticle (CoFe₂O₄-HSA) based novel biosensor system consisting of a cobalt ferrite–chitosan nanocomposite modified glassy carbon electrode (CoFe₂O₄-HSA/CT/GCE) with a high BET surface area (235 m² g⁻¹; particle size: ∼10 nm) for sensitive and selective non-enzymatic detection of UA even in the presence of different interferents (urea, glucose, ascorbic acid, cholesterol, and a mixture of these). CoFe₂O₄ nanoparticles were synthesized by a simple route under ambient conditions. The proposed enzyme-free UA sensor exhibited synergistic electrocatalytic activity for UA and displayed a wide sensing range (1.99–19.23 μM) with quite a low limit of detection (LOD) (0.3 μM), and high sensitivity (42.57 × 10³ μA mM⁻¹ cm⁻²) even between temperatures of 30 and 70 °C and in the presence of different types of interferents. Further, the sensing performance of the CoFe₂O₄-HSA/CT/GCE biosensor was validated by estimating UA concentration in a human urine sample using the currently developed method and the clinical procedure. The sensitivity, selectivity and stability (durability) of the reported biosensor make it a suitable potential candidate for biomedical applications.