*4.4. OTA Detection in Wheat Flour and Red Wine Samples*

Wheat flour and red wine samples were purchased from local supermarkets. Mix aliquots of wheat flour (1 g), different concentrations of OTA and 10 mL of extraction solvent (methanol: water, 6:4 (v/v)) in a vortex mixer for 5 min. After centrifuging for 10 min, the supernatant was removed and diluted with buffer, and then used for detection. At the same time, by adding different concentrations of OTA to the solution containing 1% red wine to prepare three samples with OTA concentration of 10 pM, 50 pM, and 200 pM respectively. All samples were then detected and analyzed as described above.

**Author Contributions:** M.Q. and W.H. designed biological experiments; M.Q. performed the experimental work, analyzed test data and drafted the manuscript; L.W. conducted the experiments and provided technical support; Y.W. contributed to the discussion of the algorithm and simulation software; Y.D. answered doubts during research and commented on the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was funded by the Natural Science Foundation of Shaanxi Province (No. 2020JM-298).

**Conflicts of Interest:** The authors declare no conflict of interest.
