Ultra-Thin Graphene Oxide Composite DNA Polymerization Gels

DNA polymerization gels exhibit high swelling, as high as a 100-fold volumetric increase, based on the sequential insertion of DNA hairpins. They offer programmability based on DNA hybridization with high specificity and the potential for the integration of biomolecular circuits, which is of broad relevance to tissue engineering and soft robotics. Here, we incorporated graphene oxide (GO) nanosheets into the polymerization gels to enhance functionality. The composites are stiffer and enable the gels to be structured in significantly thinner films, as thin as 8 µm. We observe that the GO-DNA polymerization gel composites retain their sensitivity to DNA-induced shape transformation, such as swelling and shrinking, akin to controls without GO, but with accelerated shrinking rates. We anticipate that the combination of thinner gels with more rapid shrinking, combined with the functionality of GO (such as optical absorbance), enhances their potential for use in flexible devices, soft robotics, and drug delivery. The study also highlights the potential to incorporate other nanoparticles (e.g., noble metal, semiconducting, ferromagnetic) into DNA polymerization gels to enhance optical, electronic, and magnetic functionality.