‘Gate effect’ in molecularly imprinted polymers: the current state of understanding

The so-called ‘gate effect’ is frequently used in electrochemical signal transduction for chemosensing developed using recognition units based on molecularly imprinted polymers (MIPs). A vast majority of different reported MIP electroanalytical systems makes the gate effect definition difficult to be established precisely, thus resulting in ambiguity and complexity. In the MIP literature, the gate effect is predominantly considered as an electrode–electrolyte phenomenon, which depends on the MIP film nature. However, most of the reports do not describe or confirm the origin of this effect. The present review critically evaluates representative original articles on the subject to increase understanding the origin of the gate effect operation in MIP-based electrochemical chemosensors.