A novel nanoclay/MWCNTs nanocomposite-based enzymatic biosensor for electrochemical detection of uric acid

The growing demand for rapid, low-cost biomarker detection has accelerated development of point-of-care electrochemical biosensors, yet their broader adoption is still constrained by limited reproducibility, stability, and scalable fabrication, especially for nanomaterial-modified electrodes. Here, we introduce an electrochemical biosensor for uric acid detection based on a bentonite nanoclay (Bent) and multi-walled carbon nanotubes (MWCNTs) nanocomposite film deposited via a custom spray-coating method. The fabrication process was systematically characterized to evaluate the influence of Bent incorporation on film morphology, electrode surface properties, and electrochemical behavior. Experimental results confirmed that Bent improved homogeneity and film-forming behavior within the MWCNTs network, contributing to enhanced sensing performance. The resulting biosensor exhibited high sensitivity (13.91 mA mM^-1 cm^-2) with a linear range of 10-2000 μM and a limit of detection of 5.31 μM. Notably, the developed sensor maintained acceptable recovery (92.2-110.8 %) even in contrived samples. Overall, this study demonstrates a reproducible lab-scale fabrication approach and highlights the potential of Bent for enabling highly sensitive and stable biosensors, offering a promising route toward real-world point-of-care applications.