This year, we combined synthetic biology with other disciplines to develop a device and implemented our project in landmine detection. The device was intended to help the inhabitants of the minefields and demining soldiers to minimize the casualty and injury caused by landmines. The success of our project will also contribute to the demining efforts worldwide. With the implementation of our device, we hope these inhabitants would have a relatively safe place to live. We hope that our device would be used extensively at the China-Vietnam border and any other place with similar scenario. The optical biosensors can be dropped into a minefield by drones, generate electronic signal via the photoelectric conversion system and transmit the signal to a smartphone. Then, a designated app will analyze the collected signal and design a optimal landmine detection route. During this process, the deminers only need to control the device remotely using an application loaded on a smartphone, which should greatly reduce the chance of physical injuries. In addition, our device can be recycled by replacing the hydrogel, which reduces the consumption of natural resources. As an environmentally friendly device, the hydrogel is tightly attached to the interior wall of the device, which ensures the integrity of the device during its mission. Besides, to prevent any potential biosafety issue due to the nature of bacteria, we will use amino acid-deficient bacterial strains whose D-alanine isomerase gene was knocked out. Due to the lack of D-alanine, the engineered bacteria will not survive after detaching from the hydrogel, which improves the biosafety of our device.
The task to enhance the engineered bacterial sensor output and provide a strong, fast signal was very challenging. We needed to continuously reduce the detection threshold of the target chemical to improve the application of our project in the real world. Last but not least, our device also has a wide range of applications. Through altering the DNA sequence of the promoter, the engineered bacteria could be potentially activated by different chemicals and thus used for their detection. Through improving the promoter sensitivity and transcription activator capability, we can possibly reduce the detection threshold of the device to trace amounts. Because of its high sensitivity and simple operation, we predict that this kind of device will have broadly practical prospects in the field of chemical detection in future. Therefore, it is a fertile and promising research topic to diversify the applications of our device.
Currently, we really hope that our device can be utilized in military demining to help the world dispose landmines and protect ecological environment and human beings from these potential threats!