A sensitive ZIF-67/ MWCNTs composite-based sensor for the detection of sunset yellow in food and beverages

Abstract

This study introduces an innovative sensing platform designed for the detection of sunset yellow (SY). The platform employs a composite electrode material comprising of a zeolitic imidazole framework (ZIF-67) and multiwalled carbon nanotubes (MWCNTs) on a glassy carbon electrode (GCE). The synergy between ZIF-67 and MWCNTs leads to an enhancement in the electrochemical sensing behaviour for SY oxidation. Notably, the electrostatic interaction between ZIF-67 particles and MWCNTs results in a 6.26-fold increase in the current response. Additionally, the charge transfer resistance (Rct) was remarkably low, measuring at only 114 Ω. Under ideal conditions, the SY sensor demonstrated a minimum detectable concentration (LOD) and quantifiable concentration (LOQ) of 0.103 and 0.343 µM, respectively. The detection of SY was effectively conducted in snacks and beverages, showcasing its practical applicability. The results obtained demonstrate exceptional mean relative standard deviations (RSDs) < 1 %, indicating high precision. Additionally, the recovery ranges achieved, ranging from 95 % to 105 %, validate the sensor’s reliability and accuracy. Furthermore, the chemical reactivity of SY was investigated through density functional theory (DFT) calculations, which identifies the redox-reactive site in SY, aligning with the postulated reaction mechanism observed in cyclic voltammograms. Monte Carlo (MC) simulations provide insight into the electrostatic and covalent interactions between the functional groups of the analyte and the designed sensor. This novel sensing approach demonstrates significant promise in the identification and surveillance of artificial food colourants in the food manufacturing sector.