Probing the Conformational States of a pH-Sensitive DNA Origami Zipper via Label-Free Electrochemical Methods

DNA origami structures represent an exciting class of materials for use in a wide range biotechnological applications. This study reports the design, production, and characterization “zipper” structure, which contains nine pH-responsive locks. Each lock consists two parts that are attached to zipper’s opposite arms: hairpin single-stranded able form triplex through Hoogsteen base pairing. The sequences locks were selected way zipper adopted closed configuration at pH 6.5 open state 8.0 (transition pKa 7.6). By adding thiol groups, it was possible immobilize structure onto gold surfaces. immobilization process characterized electrochemically confirm successful adsorption zipper. states then probed using differential pulse voltammetry electrochemical impedance spectroscopy with solution-based redox agents. It found after immobilization, or different regimes could be determined by interrogation. These findings pave development origami-based monitoring other sensing release strategies zipper-functionalized