Electrochemical detection of single E. coli bacteria labeled with silver nanoparticles

A proof-of-concept for the electrochemical detection of single Escherichia coli bacteria decorated with silver nanoparticles is reported. Impacts of bacteria with an electrode - held at a suitably oxidizing potential - lead to an accompanying burst of current with each collision event. The frequency of impacts scales with the concentration of bacteria and the charge indicates the extent of decoration.