Determination of vanillin in different food samples by using SMM/Au@ZIF-67 electrochemical sensor

Abstract

Vanillin is a popular flavoring agent in many food products. Simple, fast, and reliable quantification of this compound is crucial for the food industry. In this work, we have developed a new electrochemical sensor for accurate detection of vanillin in various real samples. The composite electrode was made of sodium montmorillonite nanoclay (SMM) and gold nanoparticles modified ZIF-67 (Au@ZIF-67), in which SMM contributes to the large adsorption capacity of the analyte, ZIF-67 and SMM supply more sensing active sites, and gold nanoparticles provide high electrical conductivity. The sensing electrode was comprehensively characterized using Brunauer–Emmett–Teller, EDS, XRD, SEM, FTIR, and TEM, and its electrochemical behavior for determination of vanillin including the electrooxidation mechanism of vanillin and different parameters such as scan rate and pH value was investigated. The result revealed that a two electron-two proton process was involved in the electrooxidation of vanillin, which takes place more readily due to the lower potential on the surface of SMM/Au@ZIF-67/carbon paste electrode. The new composite electrode was also more sensitive to vanillin detection with an anodic peak current almost 2.6 times more than that of the bare electrode. A linear sensing concentration range was established between 1 and 1200 nM with a detection limit of 0. 3 nM and a limit of quantitation of 1 nM. For real samples, the sensor demonstrated excellent recovery rates and reliability that was comparable to the standard high-performance liquid chromatography method.

Tetrahedrally Structured CaMoO4 Nanospheres on Heteroatom-Doped Carbon Nanotubes for Sensitive Food Additive Electrochemical Sensors

“…As a result of the slope, the m/n ratio is equal to 0.73, which is close to 1. 61 As shown in Figure S5, we can see that the oxidation of Vanillin takes place at 6.15 V with a sharp intense peak. According to the m/n ratios and sharp single intense oxidation peaks, the CaMoO 4 /P-CNT/GCE electrode is capable of oxidizing Vanillin with the same number of protons and electrons.…”

“…As a result of the slope, the m / n ratio is equal to 0.73, which is close to 1 . As shown in Figure S5, we can see that the oxidation of Vanillin takes place at 6.15 V with a sharp intense peak.…”