Copper is contained in the wastewater of smelting, metal processing, machine manufacturing, organic synthesis and other industries, among which the wastewater discharged from metal processing and electroplating factories contains the highest copper content, with tens to hundreds of milligrams of copper per liter of wastewater. When this kind of wastewater is discharged into water body, it will affect the quality of water. When the copper content in water reaches 0.01 mg/L, it has obvious inhibitory effect on it. If it exceeds 3.0 mg/L, it will produce peculiar smell; If it exceeds 15 mg/L, it cannot be drunk. If farmland is irrigated with copper-containing wastewater, copper will accumulate in soil and crops, which will cause poor growth of crops, especially rice and barley, and pollute grain grains. The critical concentration of copper sulfate in irrigation water to rice is 0.6 mg/L.

  Therefore, it is urgent to develop a wide range of biosensors which can be applied to different contaminated sites to detect copper pollution, and provide direct basis for targeted elimination of copper pollution.