Effective suppression of non-specific adsorption is crucial for high-sensitive DNA hybridization sensors. Thiol-based passivation layers as generally used in DNA sensors often exhibit insufficient surface blocking and hence additional blocking agents are used to fully protect the surface from non-specific adsorption. We demonstrate that potential pulse-assisted thiol self-assembly on gold electrodes as surface passivation step in DNA assays provides minimized non-specific adsorption as evidenced by chronoamperometric and SECM measurements. Fast and highly efficient surface blocking is achieved avoiding the necessity of additional blocking steps. (C) 2018 Elsevier Ltd. All rights reserved.