High levels of aflatoxin contamination of foods are found in many developing countries around the world. Aflatoxins are known to be mutagenic and carcinogenic, therefore human exposure to aflatoxin would lead to an increased risk of hepatocellular carcinoma (liver cancer). One in every four liver cancers in Indonesia are induced by aflatoxin B1 exposure. Nowadays, aflatoxin exposure is not only a serious problem for human health, but it could also become a serious threat in terms of food security issue of a country. ITB-Indonesia team for iGEM 2013 focuses on designing a whole cell biosensor for aflatoxin B1 detection in foods. The biosensor uses Escherichia coli as the chassis to build a genetic circuit using SOS response system to detect DNA damage caused by aflatoxin B1-oxide attack. The SOS response promoter is followed by a reporter gene coding a chromoprotein, therefore the concentration of aflatoxin B1 in food samples could be easily detected by the color change of the bacteria. For the ease of usage, we will design a syringe shaped device with our whole cell biosensor in it. This device would allow aflatoxin B1 to enter the device, but would not permit the cells to leave the device.