Fabrication of an electrochemical sensing platform based on MWCNT-CONH-66-UiO and PEDOT:PSS for highly sensitive and rapid detection of sunset yellow

The out-of-range, overdose and illegal usage of sunset yellow azo dye in food will cause great damage to food safety and consumer health. In this work, a novel electrochemical sensing platform toward sunset yellow detection was prepared based on the amidated MWCNT-CONH-66-UiO and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). In MWCNT-CONH-66-UiO, the -NHCO- is produced by the amidation reaction between zirconium 2-amino terephthalate (UiO-66-NH2) and carbonylated multi-walled carbon nanotubes (MWCNT-COOH), which play significant role for the enhancement of the sensing properties of MWCNT-CONH-66-UiO/PEDOT:PSS composite. PEDOT:PSS acts as a conducting film coated on MWCNT-CONH-66-UiO and alleviates the electrooxidation of -NHCO-. The large specific surface area, good conductivity, and outstanding synergistic effect of the composite trigger off prominent sensing properties of MWCNT-CONH-66-UiO/PEDOT:PSS toward sunset yellow detection with the lowest detection limit as 3.3 nM and a sensitivity as 6.6 mA mM(-1) cm(-2) (active area of 0.15 cm(2)). Additionally, this sensor shows satisfactory results for sunset yellow detection in plain cake and marinating meat via DPV in comparison to the high-performance liquid chromatography method. The research results in this work will provide technical support for the rapid and efficient detection of azo dyes in food, animal feeds, and industrial wastewater.