Abstract
Single-stranded oligonucleotides (ssDNA) containing guanine bases in their sequences were adsorbed onto gold nanoparticles (AuNPs) by electrostatic interaction. Cyclic voltammetry of Ru(bpy) 3 2+ in the presence of the ssDNA-AuNP complex resulted in an enhanced anodic current due to the oxidation of the guanine bases of DNA. The current obtained with ssDNA-AuNP appeared much smaller than the corresponding ssDNA alone. This current reduction was due to the decrease in solvent accessibility of the guanines in ssDNA immobilized to AuNPs. A progressive decrease in the current was observed in the titration of AuNPs to ssDNA, and a minimum current was eventually obtained, indicating complete binding of ssDNA. The size dependences of AuNPs on the interaction between ssDNA and AuNP were also studied, and the ssDNA adsorbed to 5 nm AuNPs was more solvent-accessible for the Ru mediator than 13 and 30 nm AuNPs.
Original language | English |
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Pages (from-to) | 8020-8026 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry C |
Volume | 116 |
Issue number | 14 |
DOIs | |
State | Published - 12 Apr 2012 |