Aggregation effects of gold nanoparticles (AuNPs) were examined for the discrimination of single point mutations through the hybridization of oligonucleotides (25-50. nM) modified with a fluorescent Texas red dye. The sequences of oligonucleotides were designed to detect the H1N1 virus gene. Single-base mismatch detection due to different adsorption propensities of oligonucleotides could be achieved using fluorescence quenching and surface-enhanced Raman scattering (SERS) properties of the dye. We observed that the addition of perfectly matched double stranded DNA (pmdsDNA), modified with the Texas red dye in the suspension of citrate-reduced AuNPs could increase fluorescence recovery intensities more substantially than either single-base mismatched double stranded DNA (sbmdsDNA) or single stranded DNA (ssDNA). We also tested DNA hybridization under both aggregation and near non-aggregation conditions for fluorescence measurements. A spectral difference in fluorescence intensity between pmdsDNA and sbmdsDNA appeared to be more discriminating under near non-aggregation than aggregation conditions. On the other hand, the SERS intensities of pmdsDNA and sbmdsDNA decreased more significantly than that of ssDNA under aggregation conditions, whereas we could not observe any SERS intensities under non-aggregation conditions.
Bibliographical noteFunding Information:
This work was supported by the R&D program through the NRF funded by the Ministry of Education, Science and Technology ( 2011-0001316 , 2011-0003159 , 2011-0027696 ). We would like to thank Jin Park for QELS and zeta potential measurements.
All Science Journal Classification (ASJC) codes
- Surfaces and Interfaces
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry