Fig 3.

Salmonella E-DNA sensors exhibit rapid and sensitive equilibration kinetics and can discriminate Salmonella serovars. IMED chips were fabricated to contain E-DNA sensors for the detection of both S. Typhimurium and S. Choleraesuis. (A) The analytical sensitivity of each E-DNA sensor was examined by challenging with synthetic LAMP target amplicons. (B) The equilibration kinetics of the sensors was characterized by injecting saturating (100 nM) concentrations of their cognate synthetic target amplicon. (C) The cross-reactivity of each sensor was examined by challenging it with saturating concentrations (100 nM) of its own target, the target of the other sensor, and a nonspecific DNA that neither sensor targets (Table 2). All electrochemical measurements in this figure and Fig. 4 and 5 were made using a CHI 660D potentiastat (CH Instruments, Austin, TX) (see Materials and Methods). The data points and error bars represent the means and standard deviations of measurements from three independently fabricated sensors/chips. The error bars are dominated by the sensor-to-sensor variability arising from the variation in the fabrication of individual sensors/chips.