Fig. 1: Illustration of the algorithm.

a The three reactions (5), (6), and (7). b Cell population in absence of the analyte. A small amount of cells are incorrectly converted from L to H, but the population remains mostly in the L state. c Cell population in presence of a sufficiently high concentration of the analyte. Interaction with the analyte converts L cells into H cells. Additionally H cells convert other L cells into H cells. d State of the population after the analyte has been detected and was potentially removed thereafter. The high density of H cells is maintained by H cells continuously converting L cells into H cells.