Development of a label-free plasmonic gold nanoparticles aggregates sensor on the basis of charge neutralization for the detection of zearalenone

•AuNPs aggregates could be rapidly formed based on charge neutralization.•The electrostatic repulsion between AuNP aggregates prevents further aggregation.•The strategy eliminates the instability of salt-induced AuNPs aggregates.•A label-free dual-channel sensing strategy was applied to detect zearalenone.