Comparison of Lateral Flow Immunoassays with Gold Nanoparticles of Different Shapes for Simultaneous Detection of Two Triazole Fungicides in Fruits and Berries

Rapid and productive monitoring of pesticide residues in food is essential for effective food safety. In this study, a lateral flow immunoassay (LFIA) was developed for the simultaneous detection of two triazole fungicides, cyproconazole and difenoconazole, in fruits and berries. The assay was realized using an indirect competitive format and two types of gold nanoparticles, namely nanospheres and nanoflowers, as labels. The chosen nanoflowers-based assay, which was chosen for its greater sensitivity, achieved visual and instrumental limits of detection of 0.6 ng/mL and 0.01–0.02 ng/mL for cyproconazole and 4 ng/mL and 0.20–0.75 ng/mL for difenoconazole, respectively. The assay was successfully applied to plum, cranberry, and cherry extracts, with recoveries ranging from 91% to 113% for cyproconazole and from 92% to 119% for difenoconazole.