Role of Introduction of a Resistor in Series with the Working Electrode in Impedance Related Electrochemical Measurements

Intentional introduction of a resistor in series with the working electrode during electrochemical measurements can apparently change the constituents of the electrochemical system. The introduced resistor behaves like the uncompensated solution resistance, which was often regarded as an unwanted factor. However, the introduction of the resistor brings substantial benefits in some circumstances such as (a) compressing the impedance dynamic range of an electrochemical system and making the time domain EIS measurement more reliable; (b) tuning the RC time constant of an electrochemical system to a larger or even desired value and making the potential step based capacitive biosensing more flexible.