Design and fabrication of lanthanum hexaboride on functionalized carbon black nanocomposites for electrochemical detection of morin in food matrices.

Developing efficient electrochemical sensors for flavonoid detection remains challenging due to weak analyte-electrode interactions and limited conductivity of existing materials. In this study, a novel nanocomposite of lanthanum hexaboride anchored on functionalized carbon black (LaB6@f-CB) is designed as a robust sensing platform for morin detection. The binder-free synthesis was confirmed by structural and spectroscopic analyses, where XRD confirmed the crystalline cubic phase of LaB6, while TEM showed the uniform distribution of LaB6 over f-CB, providing abundant active sites, enhanced electron transfer, and strong morin adsorption. The LaB6@f-CB/GCE exhibits an enhanced oxidation peak with a wide linear detection range (0.05-1550.51 μM), high sensitivity (12.85 μA μM-1 cm-2), and a low detection limit (0.042 μM). Excellent repeatability, selectivity, and performance in real food matrices (mulberry leaves, guava leaves, grapes, and almond milk) highlight the practical applicability of this LaB6-based ceramic-carbon hybrid for bioactive molecule sensing.