Genetically encoded RNA-based sensors for intracellular imaging of silver ions

Abstract

Silver has been widely used for disinfection. The cellular accumulation of silver ions (Ag⁺) is critical in these antibacterial effects. The direct cellular measurement of Ag⁺ is useful for the study of disinfection mechanisms. Herein, we reported a novel genetically encoded RNA-based sensor to image Ag⁺ in live bacterial cells. The sensor is designed by introducing a cytosine–Ag⁺–cytosine metallo base pair into a fluorogenic RNA aptamer, Broccoli. The binding of Ag⁺ induces the folding of Broccoli and activates a fluorescence signal. This sensor can be genetically encoded to measure the cellular flux and antibacterial effect of Ag⁺.