A highly uniform CuO@SiO2 porous sphere with improved electrochemical sensing performance for the accurate determination of vanillin in food samples

A porous sphere of [email protected]2 was obtained by simple calcination of the copper silicate (CuSiO3) sphere. The formation of the porous sphere was studied in detail with the support of various physical characterization techniques. The [email protected]2 was coated on an electrode surface where it demonstrates high catalytic activity for the electro-oxidation of vanillin in phosphate buffer solution (PBS; pH 7.0). The modified electrode has good surface adsorption (1.861 × 10−10 mol cm−2) and rate constant (2.866 × 105 cm3 mol−1 s−1) characteristics for vanillin detection. The [email protected]2-modified surface exhibited good linear range (0.05 μM–1.2 μM and 6.2 to 111.2 μM), detection limit (53 nM), sensitivity (2.88 μA μM−1 cm−2), selectivity, stability, and reproducibility. The [email protected]2-modified electrode was further examined for the determination of vanillin in real samples including biscuits and chocolates with satisfactory recoveries.