NiFeCo-modified bucky paper electrodes for sensitive and selective uric acid detection

Abstract

This study explores a convenient electroreduction-based method for developing ternary metallic alloy nanostructured self-supported buck paper electrodes (BPEs) for non-enzymatic uric acid (UA) detection. The impact of variable ratios of constituent nickel (Ni), iron (Fe), and cobalt (Co) elements on the nanostructured BPE’s electrochemical performance towards UA’s electrocatalytic oxidation was investigated. BPE’s innovative one-step electrochemical modificationwith trimetallic nanostructured alloys (NiFeCo) resulted in reproducible electrodes. The morphological and elemental composition analysis of the synthesized ternary metallic alloy nanostructured electrodes (NiFeCo/BPE) was performed using scanning electron microscopy and energy-dispersive X-ray spectroscopy, confirming the presence of Ni, Fe, and Co within the synthesized NiFeCo/BPE. The NiFeCo/BPE were comparatively evaluated against bimetallic alloy nanostructured electrodes (NiFe/BPE and NiCo/BPE). The resulting NiFeCo/BPE demonstrated a wider detection range of 10 µM to 1500 µM UA due to more electrochemical active sites when compared to the bimetallic nanostructured alloy electrodes. The NiFeCo/BPE demonstrated a sensitivity of 7.50 µAµM−1cm−2 with a detection limit of 5.02 µM towards UA. The fabricated self-supported NiFeCo/BPE sensor exhibited excellent selectivity in the presence of common interferents (e.g., ascorbic acid, dopamine, uric acid, glycine, fructose, and glucose). It showed promising utility in serum samples, with standard recoveries above 95.4 %. This study underscores the significance of uniform deposition of NiFeCo nanostructures, which is critical to unlocking the potential of bucky paper electrodes in developing flexible biosensors for broader range detection of uric acid without the need for enzymes.