Ultrasensitive Ti₃C₂Tx@Pt-Based Immunochromatography with Catalytic Amplification and a Dual Signal for the Detection of Chloramphenicol in Animal-Derived Foods

Herein, a catalytic amplification enhanced dual-signal immunochromatographic assay (ICA) based on Pt nanoparticles (Pt NPs) modified with Ti(3)C(2)Tx MXene (Ti(3)C(2)Tx@Pt) was first developed for chloramphenicol (CAP) in animal-derived foods. Due to the large specific surface area and abundant active sites of Ti(3)C(2)Tx@Pt, they can be loaded with hundreds of Pt NPs to enhance their catalytic activity, resulting in a significant increase in the detection sensitivity; the sensitivity was up to 50-fold more sensitive than the reported ICA for CAP. The LODs of the developed method for milk/chicken/fish were 0.01 mu g/kg, the LOQs were 0.03 mu g/kg and the recovery rates were 80.5-117.0%, 87.2-118.1% and 92.7-117.9%, with corresponding variations ranging from 3.1 to 9.6%, 6.0 to 12.7% and 6.0 to 13.6%, respectively. The linear range was 0.0125-1.0 mu g/kg. The results of the LC-MS/MS confirmation test on 30 real samples had a good correlation with that of our established method (R-2 > 0.98), indicating the practical reliability of the established method. The above results indicated that an ICA based on the Ti(3)C(2)Tx@Pt nanozyme has excellent potential as a food safety detection tool.