Visual detection of organophosphorus pesticides represented by mathamidophos using Au nanoparticles as colorimetric probe

► The AuNPs-based visual assay was established to detect organophosphorus pesticides. ► Pesticides assay originates from the inhibition on AChE-induced AuNPs aggregation. ► Mechanism was discussed by TEM, spectral analysis and design of control experiments. ► The screening of pesticides can be observed by naked eyes and absorption spectra. ► The assay possesses the merits of rapidness, cheapness and simple pretreatment.