Biofilms are ubiquitous coatings made up of microbes and secreted proteins. They can stick to our teeth, our sink drains, medical equipment, and myriad other man-made and natural surfaces. In health care, biofilms are often difficult-to-treat pests, but MIT electrical engineer Timothy Lu is hijacking their excellent self-forming abilities for potential beneficial uses.
E. coli secrete a protein known as CsgA, a building block of the so-called curli fibers that form an extracellular matrix-like structure in the biofilm. Lu’s team genetically engineered bacteria with a modified CsgA protein that could stick to gold particles. Once added to the culture media, the gold particles incorporated into the curli fibers when a small molecule signal was also present, giving the bacterial biofilm the ability to form gold nanowires or nanorods and hold an electrical charge. The curli fibers can also incorporate tiny semiconductors called quantum dots, which impart optical properties.
Going beyond ...
