Ashesi’s Engineering Department Head and her team of research interns were determined to develop a bio-sensor for gold quantification providing a non-toxic approach for small scale mining to extract gold from refractory ore, so as not to disrupt natural water or land. By enabling routine monitoring of the ore before a mining endeavor is undertaken was key.

The researchers used genetically engineered E. coli with a gold specific gold binding protein (golB) attached to a green fluorescent protein (NowGFP) as a donor partner and an acceptor partner made up of golB and a red fluorescent protein (mRuby2). In the presence of free gold, the two parts are in proximity and thus an energy transfer can take place between the donor and acceptor proteins, and the red protein will be excited by the donor and gives off a fluorescent signal. The same process can be used for extracting gold on land