Rapid Colorimetric Method Development for Detection of Fumonisins in Corn samples

Abstract

A robust colorimetric detection of fumonisin B1 (FB1) based on hydrolyzed product induced aggregation of cysteamine functionalized gold nanoparticles (Cyst-AuNPs) was established. The colorimetric assay is performed by hydrolyzing the fumonisin B1 under basic condition (pH 9) to obtain hydrolyzed fumonisin B1 (HFB1) before aggregation with Cyst-AuNPs. The aggregation of Cyst- AuNPs was marked with a change in solution color (wine-red to blue-gray) due to the interaction of hydrogen bonds between -NH2 groups of Cyst-AuNPs and -OH groups of HFB1. Under the optimum condition, a good linear standard addition curve in a range of 2.0-8.0 μg kg`1 FB1 was obtained from the plot of absorbance ratio (A645/A520) versus FB1 concentration (y = 0.0966x +0.1244, R2 = 0.9904). The limit of detection (LOD) and limit of quantification (LOQ) were 0.90 and 2.74 μg kg', respectively. Additionally, acceptable recoveries ranged from 93.1 to 99.3% and excellent inter- and intra- assay precisions were achieved less than 6.2%. The Cyst-AuNPs colorimetric method for determination of FB1 was also simple, rapid visual results, high sensitivity and selectivity over other competitive mycotoxins including aflatoxin, zearalenone, citrinin and patulin. Moreover, our developed method was successfully applied and suitable for detection fumonisin B1 in real corn samples.