We have investigated the electrostatic potential of Bacillus thuringiensis (BT) spores on various substrates by using our combined atomic force microscopy (AFM) and scanning surface potential microscopy (SSPM) technique. SSPM, also known as Kelvin probe force microscopy (KPFM), has been previously used to map the surface morphology and the corresponding local electrostatic potential of Photosystem I reaction centers [1], air-liquid interface [2], proteoliposomes [3], and bacteriorhodopsin [4] in nanometer resolution.
The adhesion of Bacillus anthracis—the cause of anthrax and a likely biological threat—to solid surfaces is important for cleanup after an accidental or deliberate release. However, directly studying B. anthracis spores with advanced instrumentation is problematic due to safety concerns. As a first step, we are examining adhesion of BT, which is a closely related species and is often used as a …