The effects of ionic strength on non-covalent interactions were investigated by using pore-forming alpha-hemolysin protein pores as stochastic sensor elements. Variation of salt concentration resulted in significant changes of association and dissociation kinetics of non-covalent interactions. The association rate of charged analytes was accelerated in an electrostatically dominated protein pore, while that of neutral species (including both hydrophobic and aromatic compounds) was retarded in hydrophobic or aromatic interaction-dominated pores. Dramatic increases in dissociation rates of the analytes were observed for all the studied non-covalent interaction systems. As a result, with the increasing salt concentration, the reaction free energies decreased while the sensitivities of nanopore sensors increased for all the non-covalent interactions studied. This finding has practical application in nanopore sensor technology. For example, under high salt condition, small organophosphate molecules could be sensed using beta-cyclodextrin (b-CD) as an adapter loaded in the lumen of a wild-type alpha-hemolysin pore.