Abstract
In this work, we report a simple but efficient voltammetric sensor for simultaneous detection of ponceau 4R and tartrazine based on TiO2/electro-reduced graphene oxide nanocomposites (TiO2/ErGO). TiO2/ErGO nanocomposites were prepared by ultrasonically dispersing TiO2 nanoparticles (TiO2 NPs) into graphene oxide (GO) solution followed by a green in-situ electrochemical reduction. TiO2 NPs were uniformly supported on ErGO nanoflakes, which provides a favorable interface for the adsorption and subsequent oxidation of target analytes. TiO2/ErGO showed remarkable electrocatalytic capacity for the oxidation of ponceau 4R and tartrazine, with minimized oxidation overpotentials and boosted adsorptive striping differential pulse voltammetric (AdSDPV) response peak currents. Under the optimal experimental conditions, the anodic peak currents of ponceau 4R and tartrazine increase linearly with the respective natural logarithm of concentrations from 0.01 to 5.0 μM. The detection limits (LOD = 3σ/s) for ponceau 4R and tartrazine are 4.0 and 6.0 nM, respectively. The extraordinary analytical properties of TiO2/ErGO/GCE are primarily attributed to the synergistic enhancement effect from ErGO nanoflakes and TiO2 NPs. Moreover, the proposed TiO2/ErGO/GCE achieves reliable determination of ponceau 4R and tartrazine in orange juice with excellent selectively, reproducibility and stability. Together with simplicity, rapidness, and low cost, the proposed sensor demonstrates great potential for on-site detection of azo colorants.
Highlights
As two typical edible synthetic azo colorants, ponceau 4R and tartrazine always coexist together to give the orange color to food like orange juice
2020, 8, 70 compactly embedded on the graphene oxide (GO) substrates without notable aggregation (Figure 1B). It can be seen from the TEM image of TiO2/GO that a great quantity of TiO2 NPs is attached onto the surface of GO
The satisfactory recoveries were obtained in the recovery assays with the accepted relative standard deviations (RSD). These results suggest that the TiO2 /ErGO/GCE could obtain reliable detection results without visible interference from the complicated matrix
Summary
As two typical edible synthetic azo colorants, ponceau 4R and tartrazine always coexist together to give the orange color to food like orange juice. Due to their outstanding advantages such as relatively lower price, good water-solubility, low microbiological contamination and high stability, ponceau. Ponceau 4R and tartrazine contain poisonous and carcinogenic aromatic ring structures and azo functional groups (–N=N–). Ponceau 4R and tartrazine likely lead to many adverse health effects such as allergies, neurobehavioral toxicities and cancers if they are excessively consumed [2,3,4]. The dosages of ponceau 4R and tartrazine have been severely restricted by laws and regulations. In China, the maximum permitted dosages for ponceau 4R and Chemosensors 2020, 8, 70; doi:10.3390/chemosensors8030070 www.mdpi.com/journal/chemosensors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
