Building a sustainable project has been one of the biggest considerations for iGEM XHD-Wuhan-Pro-China 2022. We always remind ourselves to provide a low-cost and easy-to-operate heavy metal detection device for areas in need, especially in remote heavy metal-contaminated areas. We believe that our project will bring us closer to the goal of sustainable development. From these 17 Sustainable Development Goals (SDGS), our team used three of them as our SDG compliance guidelines:

#11 Sustainable Cities and Communities

#14 Life Below Waer

#15 Life On Land

Zinc itself is non-toxic, but in the process of roasting zinc sulfide ore, melting zinc, smelting other metals containing zinc impurities, as well as in the process of copper casting a large amount of zinc oxide and other metal soot, have direct harm to people. The United States released 159,922 tons of zinc into the atmosphere in 1968, about 30 percent of which came from zinc smelting, more than 30 percent from steel production, and 18 percent from waste incineration. Other causes of zinc pollution include wear on rubber tires and burning coal.

Zinc in the soil can be divided into water-soluble zinc, substitution zinc, insoluble zinc (zinc in minerals,) and organic zinc. Zinc in soil comes from various soil-forming minerals. The weathered zinc enters the soil solution in the form of Zn2+, and may also become the monovalent complex ions Zn(OH)+, ZnCl+, Zn(NO3)+, etc., sometimes forming the precipitation of hydroxide, carbonate, phosphate, sulfate, and sulfide. Zinc ions and zinc-containing complex ions participate in the substitution reaction in soil, often adsorbed and fixed. The enrichment of zinc in the soil inevitably leads to the enrichment in the plant, which is not only harmful to the plant, but also to the people and animals who eat the plant. Zinc-containing sewage irrigated farmland has a great influence on the growth of crops, especially wheat, resulting in uneven emergence of wheat, fewer tillers, short plants, and yellowing of leaves. The zinc acting on plants is mainly in the substitutional form. Excessive zinc can also inactivate soil enzymes, reduce the number of bacteria and weaken the role of microorganisms in the soil.

So for the stable development of the city, we need some solutions to monitor the concentration of zinc ions in the atmosphere, in the atmosphere and to reduce the concentration of zinc ions. We believe that our design of a zinc ion sensor will be reliable and effective way. It can be used to detect the concentration of zinc ions in different environments. We just take samples from different environments and add them to our zinc sensor. Through the zinc sensor designed by us, we can simply monitor whether the concentration of zinc ions in a certain environment is within the normal range, and control the concentration in other ways for all environments that are not within the normal range.

Zinc wastewater pollution has been a recent problem, such as the misuse of zinc industrial wastewater discharged into the water. Detectable levels of excessive zinc ions have been found in sewage, drinking water, rivers, coastal waters, and animal tissues. Ultimately, this poses a threat to the environment and ecosystems as so-called heavy metal pollution, especially in high-income countries where zinc-related industries are quite affordable for many governments, businesses, and industries. It is somewhat ironic if we compare this situation to parts of the developing world where there is little access to functioning new metal smelting and use. Although zinc pollution plays an obvious role in industrial production and smelting, the input-output ratio of the low-output type of zinc industry is certainly controversial. This is the source of our product zinc sensor. It aims to be a simple, cheap, and quick way to monitor zinc concentrations in specific environments, including water sources everywhere. We believe this function will contribute to this sub-goal of protecting organisms in the aquatic environment from zinc contamination by monitoring zinc ion concentrations and taking timely countermeasures.

With the rapid development of the global economy and the acceleration of industrialization, the types and quantities of agricultural chemicals have increased dramatically, resulting in increasingly serious heavy metal pollution in soil. Heavy metals are harmful and toxic pollutants that are difficult to be degraded. When they enter the soil, they will not only degrade the soil quality and reduce the yield and quality of crops but also enter human and animal bodies through direct contact or the food chain, posing a serious threat to the ecological environment and human and animal health. Therefore, it is necessary to understand and evaluate the degree of heavy metal pollution and environmental quality in soil, so as to timely control and repair them.

In recent years, scholars have gradually realized the influence of heavy metals on biological mediated ecological processes. We believe that our design of a zinc ion sensor will be a reliable and effective way. It can be used to detect the concentration of zinc ions in different soil environments. We just take samples from different environments and add them to our zinc sensor. Through the zinc sensor designed by us, we can simply monitor whether the concentration of zinc ions in a certain environment is within the normal range, and control the concentration in other ways for all environments that are not within the normal range.