A simple sensing platform based on a 1T@2H-MoS₂/cMWCNTs composite modified electrode for ultrasensitive detection of illegal Sudan I dye in food samples

The work presented here describes a highly sensitive and simple electrochemical sensor for the detection of Sudan I dye based on a nanocomposite made of MoS₂ heterogeneous nanosheets (1T@2H-MoS₂) and carboxylated carbon nanotubes (cMWCNTs) (1T@2H-MoS₂/cMWCNTs). XPS results indicate that the content of 1T phase MoS₂ was estimated to be 72% in 1T@2H-MoS₂. Electron microscopy results show that the tubular cMWCNTs are uniformly interwoven in MoS₂ nanosheets to form a three-dimensional network structure. Due to the synergistic electrocatalytic ability and high electroactive surface area, the 1T@2H-MoS₂/cMWCNTs modified electrode demonstrated excellent analytical performance for Sudan I, including simple operation, good stability and a wide linear range from 5.00 × 10^-9 to 2.00 × 10^-6 mol L^-1 and 2.00 × 10^-6 to 1.00 × 10^-4 mol L^-1 with an ultra-low detection limit of 1.56 × 10^-9 mol L^-1. The recoveries of Sudan I from spiked real samples (chilli powder and ketchup) were in the range of 95.60% to 106.10% with low RSD (<5%), indicating that the 1T@2H-MoS₂/cMWCNTs modified electrode is a promising tool for the analysis of illegal Sudan I in food samples.