Nickel Cobaltite Nanoplate-Based Electrochemical Sensing Platform from Printable Inks for Simultaneous Detection of...

2D metal oxide-based nanomaterials have emerged as an exciting area of research owing to their rich electrochemical properties and diverse applications, including biosensors. In this work, we have synthesized ultra-thin Co₃ O₄ , NiO, and NiCo₂ O₄ nanostructures supported on a carbon cloth and printed graphite/Kapton substrates following thermal reduction of self-assembled metal alkanethiolates. These nanostructures act as a sensing platform for simultaneous detection of dopamine (DA) and uric acid (UA), important biological molecules in physiological and pathological tests. The ultrathin 2D nanoplates of NiCo₂ O₄ spinel formed in this study exhibit high electrochemical activity than pristine NiO and Co₃ O₄ . The electrochemical characterization studies indicate that NiCo₂ O₄ possesses a high potential for DA and UA with a peak separation of ∼140 mV, high sensitivity, and excellent selectivity. The low-cost and disposable, single-shot probe biosensors fabricated in this work possess a wide working range of 0.001-1000 μM with detection limits of 0.33 and 0.49 nM for DA and UA, respectively, with a practically achievable limit of quantification of ∼1 nM. Multiple sensing electrodes are printed on graphite/Kapton all at once following this method with improved reproducibility for DA and UA sensing further extending the scope of work towards mass fabrication and practical usage.