Development of an immunochromatographic test strip for the detection of isofetamid in kiwifruits, grapes, and strawberries

Isofetamid (ISO), a new generation succinate dehydrogenase inhibitor fungicide, finds extensive application in crops to manage diseases associated with gray mold and sclerotinia. For the purpose of ISO level monitoring, a test strip using colloidal gold immunochromatography was devised specifically to detect ISO residues within fruits. The test strip had calculated detection limits of 0.027, 0.066 and 0.028 mg/kg in kiwifruit, grape, and strawberry, respectively. The quantitative detection of ISO could be achieved within 8 min. Kiwifruits, grapes, and strawberries were simultaneously analyzed using the test strip and LC-MS/MS. The obtained findings showed ISO recovery rates spanning 91.7%-110.0%. Furthermore, the LC-MS/MS outcomes concurred notably with the findings from the test strip. Thus, the test strip we developed proves applicable for on-site ISO residue detection in fruits.