Electropolymerized 4-Aminobenzoic Acid Based Voltammetric Sensor for the Simultaneous Determination of Food Azo Dyes

Abstract

Electrochemical sensors with polymeric films as a sensitive layer are of high interest in current electroanalysis. A voltammetric sensor based on multi-walled carbon nanotubes (MWCNTs) and electropolymerized 4-aminobenzoic acid (4-ABA) has been developed for the simultaneous determination of synthetic food azo dyes (sunset yellow FCF and tartrazine). Based on the voltammetric response of the dyes’ mixture, the optimal conditions of electropolymerization have been found to be 30-fold potential scanning between −0.3 and 1.5 V, at 100 mV s−1 in the 100 µmol L−1 monomer solution in phosphate buffer pH 7.0. The poly (4-ABA)-based electrode shows a 10.5-fold increase in its effective surface area and a 17.2-fold lower electron transfer resistance compared to the glassy carbon electrode (GCE). The sensor gives a sensitive and selective response to sunset yellow FCF and tartrazine, with the peak potential separation of 232 mV in phosphate buffer pH 4.8. The electrooxidation parameters of dyes have been calculated. Simultaneous quantification is possible in the dynamic ranges of 0.010–0.75 and 0.75–5.0 µmol L−1 for both dyes, with detection limits of 2.3 and 3.0 nmol L−1 for sunset yellow FCF and tartrazine, respectively. The sensor has been tested on orange-flavored drinks and validated with chromatography.

Voltammetric Sensor Based on the Poly(p-aminobenzoic Acid) for the Simultaneous Quantification of Aromatic Aldehydes as Markers of Cognac and Brandy Quality

“…An irreversible oxidation of the redox probe is observed at the bare GCE, which is in line with the report in [ 25 , 40 ]. Therefore, chronoamperometry at 0.60 V is used for the estimation of GCE electroactive surface area ( Figure S3 ).…”

“…Electrodes modified with MWCNTs and oxidized MWCNTs functionalized with 4-aminophenyl phosphonic acid [ 38 ] and aminobenzene acids [ 39 ] have been reported. Electropolymerized p -aminobenzoic acid ( p -ABA)-based sensors have been reported for the various types of organic analytes, i.e., food azo dyes [ 40 ], toxic phenols [ 41 , 42 ], and pharmaceuticals [ 43 , 44 , 45 ]. MWCNTs have been used as a platform for the electrodeposition of polymers due to the high conductivity and surface area allowing a higher load of polymer [ 40 , 45 ].…”

“…Electropolymerized p -aminobenzoic acid ( p -ABA)-based sensors have been reported for the various types of organic analytes, i.e., food azo dyes [ 40 ], toxic phenols [ 41 , 42 ], and pharmaceuticals [ 43 , 44 , 45 ]. MWCNTs have been used as a platform for the electrodeposition of polymers due to the high conductivity and surface area allowing a higher load of polymer [ 40 , 45 ]. The application of p -ABA-modified electrodes for the quantification of natural phenolics has not been reported to date and can be a promising approach.…”

Layer-by-Layer Combination of MWCNTs and Poly(ferulic acid) as Electrochemical Platform for Hesperidin Quantification

“…The electrochemical polymerization of suitable monomers is a powerful way to create voltammetric sensors with improved responses to a target analyte [1][2][3][4]. Major attention has been focused on conductive polymers such as polyaniline [1,5], polypyrrole [3], polythi-ophene [1,6], aminobenzoic acids [7,8], and their derivatives. On the other hand, nonconductive polymers, which are based on electropolymerized phenols [9], aminophenols [10,11], and natural phenolics [12], have been successfully used in biosenors and chemical sensors.…”

“…Linear sweep voltammetry 6. Screen-printed electrode 7. Adsorptive differential pulse voltammetry 8.…”