The potential of electrochemistry for one-pot and sensitive analysis of patent blue V, tartrazine, acid violet 7 and ponceau 4R in foodstuffs using IL/Cu-BTC MOF modified

Abstract

Since excessive use of synthetic dyes has negative effects on human health, their determination in foodstuff is
necessary. A sensitive sensor was developed based on copper BTC metal–organic framework (Cu-BTC MOF) and
1-ethyl-3-methylimidazolium chloride as an ionic liquid (IL) in an attempt to modify the carbon paste electrode
and to improve the active surface area and electric conductivity so that electron transfer is faster for electro
analysis. For the first time, high sensitivity, excellent conductivity, and appropriate selectivity of the electrochemical
sensor have been evaluated as a new study for simultaneous determination of tartrazine, patent blue V,
acid violet 7 and ponceau 4R. Excellent sensing performance of the proposed electrode was confirmed for patent
blue V as an outstanding sensor, according to the low limit of detection of 0.07 μM, with a wide linear concentration
range of 0.08 to 900 μM and reasonable recovery. In order to characterize the electrochemical
behavior of electrode, cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance
spectroscopy are used. Various techniques such as scanning electron microscopy (SEM) with energy dispersive XRay
analysis (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) are employed to
verify the structure of copper BTC metal–organic framework. The results revealed close packing of hierarchically
porous nanoparticles and crystal structure of Cu-BTC MOF, with the edge of each particle around 20–37 nm. The
analytical performance of the suggested electrochemical sensor is acceptable in foodstuffs such as jellies, condiments,
soft drinks, and candies.