We've done an investigation about water pollution in the past few months. Through street interview and online questionnaires, 1,000 valid replies were collected from 4 countries. Here's the conclusion: Althrough different countries' water pollution is in different degrees. People are very worried this. What's more, some people are urging a both cheap and convenient method to tell them whether the water is safe to drink. And that's the reason why we do this project.

We had constructed 14 different parts. All of them, including several ion sensors, have ribB CDS. Our experiments had confirmed that the expression degree of ribB can influence the riboflavin production. Then we had taken them into MFC and the voltage showed that our genetic engineered E.coli could response the change of Cu ²⁺ concentration. Thus we linked the concentration of metal ion to the electricity production.

Based on the wet lab results, we constructed the 'Micro Holmes concentration measurement system' which contained a Microbial Fuel Cell, a Microprogrammed Control Unit, a voltage magnification circuit board, an Analogue-to-Digital Conversion chip, a set of input and output devices and one or several kinds of bacteria.