Nanoarchitecturing of MoC nanospheres on carbon cloth as an electrochemical sensing platform for determination of caffeic acid in tea samples.

In the present paper, carbon cloth (CC) as a flexible substrate was modified by molybdenum carbide nanospheres (MoC NSs @CC) by the drop-coating method to develop a sensitive electrochemical platform for detecting caffeic acid. The uniform MoC NSs were prepared via an easy route followed by pyrolyzing the precursor of the Mo-polydopamine (Mo-PDA) NSs. The MoC NSs were characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDS), Raman spectroscopy (RS), and electrochemical methods. CC not only gave a flexible feature to the sensor but also provided a larger surface area for MoC NSs. Meanwhile, the excellent conductivity and large electroactive specific surface area of MoC NSs exhibited excellent electrocatalytic performance for caffeic acid determination. The developed sensor showed high sensitivity and selectivity, good reproducibility, and long-term stability with a limit of detection (LOD) and a wide linear range of 0.001 μM (S/N = 3) and 0.01-50 μM, respectively. In addition, the MoC NSs @CC sensor showed a promising application prospect for the detection of caffeic acid in green and black tea samples, indicating its importance in food safety and the food industry.