Effect of pH on the Interaction of Gold Nanoparticles with DNA and Application in the Detection of Human p53 Gene Mutation
1 Department of Biomaterials, College of Materials, Xiamen University, Xiamen, 361005, China
2 State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, China
3 Institute of Biomedical Engineering, Chinese Academy of Medical Science and Peking Union Medical College, Tianjin, 300192, China
Nanoscale Research Letters 2008, 4:216-220 doi:10.1007/s11671-008-9228-zPublished: 10 December 2008
Gold nanoparticles (GNPs) are widely used to detect DNA. We studied the effect of pH on the assembly/disassembly of single-stranded DNA functionalized GNPs. Based on the different binding affinities of DNA to GNPs, we present a simple and fast way that uses HCl to drive the assembly of GNPs for detection of DNA sequences with single nucleotide differences. The assembly is reversible and can be switched by changing the solution pH. No covalent modification of DNA or GNP surface is needed. Oligonucleotide derived from human p53 gene with one-base substitution can be distinguished by a color change of the GNPs solution or a significant difference of the maximum absorption wavelength (λmax), compared with wildtype sequences. This method enables detection of 10 picomole quantities of target DNA.