(420q) Oligodeoxynucleotide Conjugated Graft-Copolymer-Stabilized Gold Nanoparticle Scaffolds for In Situ PCR Diagnostic Assays

Polymerase chain reaction (PCR) has been widely used in molecular biology for various applications, including gene sequencing, disease diagnostics, and gene functional analysis by amplification of target DNA sequences. Up to now, however, there have been no successful reports of gold nanoparticles (AuNP) as supports for PCR to detect target DNA. This has partly been because AuNP-DNA scaffolds are unstable to the thermal cycling and free thiols used in PCR, and partly because enzymes interact with AuNPs. We report that both of these problems are solved by using AuNPs stabilized by multiple thiolated poly(L-lysine)-graft-poly(ethylene glycol), PLL-g-[PEG:PSH]. The multi-thiolate graft copolymers were conjugated to oligodeoxynucleotide (ODN) primers via “click chemistry” and bound to AuNPs to yield AuNP-ODN scaffolds that successfully primed PCR reactions, as demonstrated by gel electrophoresis and fluorescent analysis. Moreover, the scaffolds were applied to rapid DNA diagnostics in a single PCR tube with magnetic particles through color change without any instrumental analysis. We anticipate that AuNP-ODN scaffolds might be integrated into microarray or sequencing technologies that currently rely on microscale surfaces and fluorescence signal analysis.