Sequence-Specific Metallization of Single Divalent DNA-Nanoparticle Conjugates: A Potential Route to Single-Electron Devices

• Published in: ChemPlusChem (Weinheim, Germany) Germany), 2012-07, Vol.77 (7), p.592-597
• Main Authors: Wang, Guoqing, Ishikawa, Ayako, Eguchi, Asumi, Suzuki, Yasunobu, Tanaka, Shukichi, Matsuo, Yasutaka, Niikura, Kenichi, Ijiro, Kuniharu
• Format: Article
• Language: English
• Subjects: DNA recognition; nanoparticles; polymerization; sequence-specific metallization; single-electron devices
• ISSN: 2192-6506; 2192-6506
• DOI: 10.1002/cplu.201200096

Although progress has been made in the construction of single‐electron devices (SEDs), few of the reported approaches have proved practically applicable, mainly owing to their cost‐ineffectiveness and need for sophisticated instrumentation. Herein, a conceptually new method for fabricating SEDs through the metallization of divalent DNA‐nanoparticle conjugates is described. Specifically, divalent DNA copolymers that are conjugated to gold nanoparticles (AuNP) were synthesized by application of the enzymatic extension of DNA conjugated on quantum‐sized AuNPs. This conjugate structure allows the distance between the resulting poly(dG)‐poly(dC) and the AuNP to be controlled by an ssDNA spacer. To afford poly(dG)‐poly(dC) sequence‐specific metal deposition, Cisplatin capable of specific chemisorption on the poly(dG)‐poly(dC) is incubated with the divalent DNA copolymer–AuNP conjugates, followed by reduction of the Cisplatin to Pt metal at base resolution. As a result, AuNPs separated from the Pt “electrodes” by the ssDNA barriers in a single conjugate could be created as a double‐tunnel junction for SEDs. This study is thought to be an important step toward the programmable organization of DNA for use in SEDs. DNA‐specific recognition: A conceptually new strategy for fabricating single‐electron devices (SEDs) through programmable organization of DNA has been explored. Divalent DNA template primers that are conjugated to gold nanoparticles (AuNP) were prepared, followed by enzymatic synthesis of poly(dG)‐poly(dC). By application of base‐specific metallization, the divalent DNA–AuNP conjugates can be transformed into double‐tunnel junction nanostructures (see figure).