In this article, a novel plasmonic grating sensor platform was developed and tested for feasibility in sensor applications using a "lights-on" fluorescence based DNA sensor. The sensor platform combined the fluorescence enhancement of a grating-based plasmonic platform with the electric field intensifying effects of nano-scale cones and cavities. The gratings were made through a microcontact printing process that replicated HD-DVD discs in polymethylsilsesquioxane (PMSSQ) and coated in a thin gold film. Nanocavities were incorporated into the sensor platform during the printing process and nanocones were incorporated during the 100 nm gold deposition process. Fluorescently-tagged single-strand (SS) DNA molecules were immobilized onto the surface and were designed such that the molecules would fluoresce when bound to a complementary sequence. Sensor substrates were imaged after exposure to a mismatched and matched oligomer to quantify the fluorescence enhancement of the sensor. Much higher fluorescence intensity was observed on all of the plasmonic structures as compared to flat gold.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering