An embodiment provides a method for measuring an analyte of a sample, including: introducing a sample to a sample region of a measurement device; the measurement device comprising: a measurement electrode and a ground electrode contacting the sample; a low-slope reference electrode in a reference electrode assembly having an electrolyte solution, wherein the electrolyte solution is in contact with the low-slope reference electrode; wherein the electrolyte solution is electrically coupled to the sample via at least one junction; and measuring a first potential between the measurement electrode and the ground electrode; measuring a second potential between the low-slope reference electrode and the ground electrode; determining an analyte in the sample by comparing the first potential and the second potential. Other aspects are described and claimed.