Development of a gold nanoparticles-based visual immuno-sensing platform for the rapid detection of gibberellins.

As a common class of growth regulators, gibberellins (GAs) are widely used in agricultural production. However, the abuse and misuse of GAs have led to the problem of high residues in crops. The existing detection methods are still mainly instrumental, and rapid and sensitive detection of GAs remains a challenge. In this study, we designed a novel hapten scheme by analyzing the structure of GAs, which enabled the prepared mAb to simultaneously detect common GAs (GA 3 , GA 1 , GA 4 and GA 7) with high sensitivity and homogeneity. Subsequently, a colloidal gold immunochromatographic assay (GICA) for GAs detection was established by combining mAb with synthetic gold nanoparticles, which could simplify the sample pre-treatment step and the calculated limit of detection, visual limit of detection, cut-off values and linear ranges were 0.09 mg/kg, 0.2 mg/kg, 8 mg/kg, 0.13–1.36 mg/kg for rice and 0.11 mg/kg, 0.2 mg/kg, greater than 8 mg/kg, 0.13–2.45 mg/kg for tomatoes. The recovery assays of GA 3 -spiked samples ranged between 95.1% and 105.1%. The results indicate that our developed method can be used for the rapid, sensitive and efficient on-site detection of GAs in food. • A GA 3 -hapten was designed to produce a highly sensitive and versatile mAb. • A visual immuno-sensing platform was developed. • The results showed a visual LOD of 0.2 mg/kg in rice and tomato samples. • No significant difference in recovery rates were seen between GICA and ic-ELISA. [ABSTRACT FROM AUTHOR]