Disc electrodes were tested in 1x phosphate buffer saline (PBS), pH 7.4 with a short titration of target analyte using square wave voltammetry (SWV) at 120 Hz for cortisol sensors and 10 Hz and 300 Hz for phenylalanine sensors with a CH Instruments 620E potentiostat (CH Instruments, Austin, TX). Testing was completed using the following workflow: (1) we prepared sensors as normal, (2) then we collected sensor data while titrating target (3) we washed sensors in buffer solution (4) we dried sensors under vacuum with 10%w/w trehalose in PBS solution (5) we placed sensors into dry nitrogen storage (6) we rehydrated sensors and repeat the data collection of step 2. To store sensors, we deposited trehalose solution onto the sensor surface then applied -25 inHg vacuum until trehalose fully dried (~1 h). After storage, sensors were rehydrated in PBS and retested under the same conditions as before storage.