Nickel Cobaltite Nanoplate-Based Electrochemical Sensing Platform from Printable Inks for Simultaneous Detection of Dopamine and Uric Acid

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 Co3O4, NiO, and NiCo2O4 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 NiCo2O4 spinel formed in this study exhibit high electrochemical activity than pristine NiO and Co3O4. The electrochemical characterization studies indicate that NiCo2O4 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.