Fabrication of Gold nanoparticle-DNA conjugates bearing specific number of DNA for quantitative detection and well-defined nanoassembly

Abstract

Sequence-specific DNA detection is important in various biomedical applications such as gene expression profiling, disease diagnosis, drug discovery and forensic analysis. This Ph.D. work aims to develop a gold nanoparticle-based method that allows DNA detection and quantification and is capable of single nucleotide polymorphism (SNP) discrimination. First, the feasibility of combining gel electrophoresis isolation and restriction endonuclease manipulation of gold nanoparticle-bound DNA for fabricating nanoparticles bearing definite number and length of DNA was demonstrated. Second, by exploiting these nanoparticle-DNA conjugates, a quantitative DNA detection method with SNP discrimination ability was developed. The precise quantification of DNA is due to the formation of defined nanoparticle-DNA conjugate groupings in the presence of target DNA. Conjugate groupings were characterized and quantified by gel electrophoresis. A linear correlation between the amount of target DNA and conjugate groupings was found. For SNP detection, single base mismatch discrimination was achieved for both the end-and center-base mismatch.