Rhombohedral type of LaCoO3 with carbon nanofiber composite as an electrocatalyst enables the amperometry detection of vanillin in food samples

Abstract

Vanillin (VNL) is a flavoring substance that is commonly used in food preservatives and pharmaceutical industry. An overdose of VNL in food samples may cause liver and kidney damage; hence, developing a simple and stable analytical method is highly essential currently. This study develops an electrochemical sensor for the rapid detection of VNL based on a novel hybrid composite. The facile synthesis of rhombohedral-type LaCoO₃ (LCO) and LCO@CNF hybrid composites was confirmed by performing spectroscopic and morphological analysis. The highly dispersed composite of LCO@CNF was drop coated on the electrode surface and utilized to detect VNL in a physiological working environment. The analytical signal has wide concentration linearity in the range of 0.01–1670 μM with a low detection limit of 4.67 nM and high sensitivity (9.859 μA μM⁻¹ cm⁻²) using the amperometric (i–t) method. Finally, the present system was successfully applied to the rapid detection of VNL in real food samples (vanilla ice cream and cocoa biscuit) with an appreciable RSD in the range of 1.30–3.94% and a recovery rate of 98.25–102.56%.