Clicking DNA to gold nanoparticles: poly-adenine-mediated formation of monovalent DNA-gold nanoparticle conjugates with nearly quantitative yield

Abstract

Monovalent DNA-gold nanoparticle (mDNA-AuNP) conjugates hold great promise for widespread applications, especially the construction of well-defined, molecule-like nanosystems. Previously reported methods all rely on the use of thiolated DNA to functionalize AuNPs, resulting in relatively low yields. Here, we report a facile method to rapidly prepare mDNA-AuNPs using a poly-adenine (polyA)-mediated approach. As polyA can selectively bind to AuNPs with high controllability of the surface density of DNA, we can use a DNA strand with a sufficiently long polyA to wrap around the surface of an individual AuNP, preventing further the adsorption of additional strands. Based on this observation, we obtained mDNA-AuNPs with a nearly quantitative yield of~90% using 80 As, as confirmed by both gel electrophoresis and transmission electron microscope observation. The yields of mDNA-AuNPs were insensitive to the stoichiometric ratio between DNA and AuNPs, suggesting the click chemistry-like nature of this polyA-mediated reaction. mDNA-AuNPs exhibited rapid kinetics and high efficiency for sequence-specific hybridization. More importantly, we demonstrated that AuNPs of fixed valences could form well-defined heterogenous oligomeric nanostructures with precise, atom-like control.

Reactivating Catalytic Surface: Insights into the Role of Hot Holes in Plasmonic Catalysis

“…13 nm Au NPs were synthesized according to the citrate reduction method . The single DNA‐functionalized Au NPs were synthesized through Poly A‐mediated method . In brief, citrate‐protected Au NPs of 13 nm were first functionalized with BSPP stabilizers via ligand exchange.…”

Precisely Tailored DNA Nanostructures and their Theranostic Applications

“…Based on this feature, we obtained a series of fixed‐valent DNA‐AuNPs. If long enough, the polyA segment (∼80 nt) covered on AuNP surface can efficiently block the adsorption of a second strand, leading to high yielded mono‐valent DNA‐AuNPs (∼90 % yield without purification) . Compared with traditional methods, this strategy can define the valence of nanoparticles solely by DNA sequence rather than by controlling the stoichiometric ratio between DNAs and nanoparticles, thus provides nearly quantitative yields of expected products.…”

Oriented Assembly of Gold Nanoparticles with Freezing‐Driven Surface DNA Manipulation and Its Application in SERS‐Based MicroRNA Assay

“…AuNPs were pretreated with occupied reagents, e.g., adenosine triphosphate (ATP), 2‐thioethyl ether acetic acid (thiol‐PEG‐acid), or bis( p ‐sulfonatophenyl) phenylphosphine (BSPP), and further modified with probe DNA strands. Although the steric hindrance effect enables low‐density DNA conjugation on the surface of AuNPs, it is impossible to further increase DNA density . Another strategy utilized the poly adenine (polyA) sequence as an anchoring block to occupy the AuNP surface .…”