Novel Enzymatic Biosensor Utilizing a MoS₂/MoO₃ Nanohybrid for the Electrochemical Detection of Xanthine in Fish Meat

A rapid, reliable, and user-friendly electrochemical sensor was developed for the detection of xanthine (Xn), an important biomarker of food quality. The developed sensor is based on a nanocomposite comprised of molybdenum disulfide-molybdenum trioxide (MoS₂/MoO₃) and synthesized using a single-pot hydrothermal method. Structural analysis of the MoS₂/MoO₃ nanocomposite was conducted using X-ray diffraction (XRD) and Raman spectroscopy, while its compositional properties were evaluated through X-ray photoelectron spectroscopy (XPS). Morphological features were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Two-dimensional (2D) MoS₂ offers advantages such as a high surface-to-volume ratio, biocompatibility, and strong light-matter interaction, whereas MoO₃ serves as an effective electron transfer mediator and exhibits excellent stability in aqueous environments. The enzymatic biosensor derived from this nanocomposite demonstrates remarkable cyclic stability and a low limit of detection of 64 nM. It enables rapid, reproducible, specific, and reproducible detection over 10 cycles while maintaining a shelf life of more than 5 weeks. These findings highlight the potential of our proposed approach for the development of early detection devices for Xn.