Functional DNA switches: rational design and electrochemical signaling

Recent developments in nanoscience research have demonstrated that DNA switches (rationally designed DNA nanostructures) constitute a class of versatile building blocks for the fabrication and assembly of electronic devices and sensors at the nanoscale. Functional DNA sequences and structures such as aptamers, DNAzymes, G-quadruplexes, and i-motifs can be readily prepared in vitro, and subsequently adapted to an electrochemical platform by coupling with redox reporters. The conformational or conduction switching of such electrode-bound DNA modules in response to an external stimulus can then be monitored by conventional voltammetric measurements. In this review, we describe how we are able to design and examine functional DNA switches, particularly those systems that utilize electrochemical signaling. We also discuss different available options for labeling functional DNA with redox reporters, and comment on the function-oriented signaling pathways.