Abstract We investigated the interaction of As(III) with As(III)-binding DNA aptamers (Ars-3). The binding Ars-3 to was using an sequence and a few control sequences. As result, we conclude that cannot bind can adsorb onto gold nanoparticles selectivity. However, concentration could be determined by simple analysis method Ars-3, measured As(V) concentrations separately in As(III)/As(V) mixed sa...