DNA Optoelectronics: Versatile Systems for On-Demand Functional Electrochemical Applications.

Herein, we propose innovative deoxyribonucleic acid (DNA)-based gels and their applications in diverse optoelectronics. We prepared the optoelectronic DNA-based gels (^OpDNA Gel) through molecular complexation, that is, groove binding and ionic interactions of DNA and 1,1'-diheptyl-4,4'-bipyridinium (DHV). This process is feasible even with sequence-nonspecific DNA extracted from nature (<i>e.g</i>., salmon testes), resulting in the expansion of the application scope of DNA-based gels. ^OpDNA Gel possessed good mechanical characteristics (<i>e.g</i>., high compressibility, thermoplasticity, and outstanding viscoelastic properties) that have not been observed in typical DNA hydrogels. Moreover, the electrochromic (EC) characteristics of DHV were not lost when combined with ^OpDNA Gel. By taking advantage of the facile moldability, voltage-tunable EC behavior, and biocompatibility/biodegradability of ^OpDNA Gel, we successfully demonstrated its applicability in a variety of functional electrochemical systems, including on-demand information coding systems, user-customized EC displays, and microorganism monitoring systems. The ^OpDNA Gel is a promising platform for the application of DNA-based biomaterials in electrochemical optoelectronics.