The role of surface availability in membrane-induced selectivity for amperometric enzyme-based biosensors

•We investigated the role of surface availability in membrane-induced selectivity.•We characterized microelectrodes coated with the most effective selective membranes.•All configurations differentially reduced both interference and analyte sensitivity.•Membrane combinations were more effective but not more selective than single membranes.•An “inner-polymerization” further reduced surface availability in membrane combinations.