Synthetic organophosphorus (OP) compounds, which are highly toxic contaminants in agro-environment and food security, have been widely applied to pesticides. Parathion is a typical representative of organophosphorus pesticides. This year, our goal is to construct a p-Nitrophenol sensor in E.coli, which is the degradation product of parathion, in order to reflect the existence of parathion. Besides, we try constructing a degradation system to solve the pollution problem. Considering the biosafety problem, we also design a suicide system in which the lethal genes are only triggered by declining p-Nitrophenol concentration. This will enable the bacteria to commit suicide when p-Nitrophnol is sufficiently degraded.