Figure 4
Sensor chip response curves for lactate and glucose in PBS at 37 °C. (a) Lactate signal recorded in a configuration featuring one lactate oxidase (LOx)-functionalized electrode and one blank BSA electrode per drop. The same liquid was infused in both rows in parallel at a flow rate of 10 μl min−1. The tube delay represents the time needed for the medium from the syringe to reach the hanging-drop instrumented with the sensor. The arrows indicate the instances when syringes were switched to introduce a different concentration/solution. (b) Close-up view showing the artifact observed upon syringe switching, the sensor response observed upon lactate reaching the hanging drop, and the low background noise levels of all four electrodes. The data have been offset-corrected to t=0 s. Negative current values can be attributed to incomplete settling at the beginning of the measurement. (c) On-chip lactate and glucose signals simultaneously recorded in phosphate-buffered saline (PBS) under an alternating analyte flow of glucose and lactate at a flow rate of 5 μl min−1.
