Development of a gold-based lateral flow immunoassay for the determination of abscisic acid

Abstract

Abscisic acid (ABA) is a plant growth hormone that has a regulatory effect on plant physiology including accelerating fruit ripening, regulating abiotic stress tolerance and handling environmental risks. In this research, a highly sensitive monoclonal antibody (mAb) specific to abscisic acid was produced. We applied it to develop a method of lateral flow immunoassay (LFIA) on the basis of the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) to analyze the content of abscisic acid in vegetable samples. The 50% inhibitory concentration (IC₅₀) was 0.66 ng mL⁻¹ with a cut-off value of the LFIA strip of 5 ng mL⁻¹. The linear range was 0.28–2.57 ng mL⁻¹ and the calculated LOD (cLOD) was 0.14 ng mL⁻¹, respectively. The recoveries of the developed method ranged from 92.5% ± 3.2% to 102.2% ± 1.6% and 95.4% ± 3.6% to 108.2% ± 2.2% in tomato and cowpea samples with a coefficient of variation (CV) of 1.8–2.9% and 1.2–3.4%, respectively. The results showed that the developed method showed great prospects in the detection and monitoring of ABA in real food samples.