Voltammetric Sensor for Sudan I Based on Glassy Carbon Electrode Modified by SWCNT/β-Cyclodextrin Conjugate

We reported a sensitive voltammetric sensor for Sudan I determination by modifying glassy carbon electrode (GCE) with single-walled carbon nanotubes (SWCNTs)/β-cyclodextrin conjugate. The cyclic voltammetry results showed that the modified GCE exhibited strong catalytic activity toward the electro-reduction of Sudan I with a well-defined cyclic voltammetric peak at -673 mV. Differential pulse voltammetry measurement showed that the response current exhibited a linear range between 50 nM and 5 μM, and the detection limit was as low as 2.22 nM (S/N = 3). The enhanced electrochemical performance of the fabricated sensor was attributed to the combination of the excellent electrocatalytic properties of SWCNTs and the molecular recognition ability of β-cyclodextrin to Sudan I. The sensor was successfully applied to determine Sudan I in real food samples with satisfactory results.