Fig. 5

Response to saliva from nine donors using G-CA or CA1-CA2-G-CA3. a CA response from G-CA and b CA3-CA1 response from CA1-CA2-G-CA3. Each data point is the average response of 12 sensors, averaged over the time intervals 0.0–0.025, 0.025−0.05, 0.05−0.075, 0.075−0.1 and 0.1–0.125 s. The error bars are one standard deviation. The overlayer was coated with 1 mg/mL OX0245 in 0.4 M AMPSO (pH 9.5), 1 M NaCl, 1 % TX-100 and 0.5 % Surfynol 465. 7 uL of saliva obtained from one donor was applied to each sensor. The G-CA procedure was 20 s wait time, galvanostatic current of 100 nA for 5 s, followed by chronoamperometric reduction at −0.2 V for 2 s. The CA1-CA2-G-CA3 procedure was 20 s wait time, CA1 at −0.2 V for 2 s, CA2 at −0.04 V for 0.5 s, galvanostatic current of 100 nA for 5 s, followed by CA3 at −0.2 V for 2 s