Rapid and sensitive detection of chlordimeform in cucumber and tomato samples using an immunochromatographic assay

Abstract

Chlordimeform (CDM) is a broad-spectrum and highly effective insecticide and acaricide used to control pests in agriculture. We produced two monoclonal antibodies (mAbs) against CDM and developed an immunochromatographic assay to screen CDM in cucumbers and tomatoes. MAb 4A3 had high sensitivity with a 50% inhibitory concentration of 0.287 ng mL⁻¹. The assay had a cut-off value of 25 μg kg⁻¹ and a visual limit of detection (vLOD) of 1 μg kg⁻¹ in cucumbers and a cut off value of 50 μg kg⁻¹ and a vLOD of 2.5 μg kg⁻¹ in tomatoes. The calculated limit of detection (cLOD) in cucumbers and tomatoes was 0.115 μg kg⁻¹ and 0.215 μg kg⁻¹, respectively. The recovery rates were 97.9% to 106.9% for cucumbers and 97.8% to 107.4% for tomatoes, consistent with the results obtained from indirect competitive ELISA. Our findings showed that the immunochromatographic assay is an efficient and accurate method for CDM detection in cucumbers and tomatoes.