Abstract
In this work, we used the bio-organic polymer material full name (DNA), which has been widely employed in nanotechnology, in surface-enhanced Raman scattering (SERS) for biomedical sensing. A SERS substrate is presented to be used in sensing the interaction of alkaloid coralyne and DNA hybridization. We use the modified double helix DNA and weak photoreducing agent, Iragacure-2959, to synthesize rough surface flower-like gold nanostructures by photoreduction. By controlling the molar ratio of DNA, gold salt precursor and photoreducing agent, various morphologies and size of gold nanostructures can be obtained. We demonstrate the application of gold nanostructures as SERS substrate. The lowest detectable concentration of analytes, GM19 and DTNB is 10-9 M and the enhancement factor is 4.4×105 and 2.6×106, respectively. We apply this SERS substrate for sensors to detect the interaction of alkaloid coralyne and DNA. We determined the best combination ratio of coralyne and DNA by fluorescence spectroscopy. In addition, we also use the SERS intensity ratio (I736/I1318), which indicates the single-stranded and double-stranded DNA ratio, to verify coralyne concentration.