SBIR Phase I: A New Optical Detector for Dipicolinic Acid Based on the Quantum Confined Stark Effect

This Small Business Innovative Research (SBIR) Phase I project is to demonstrate the feasibility of developing a new optical sensor for dipicolinic acid (DPA) based on the quantum confined Stark effect. Dipicolinic acid is an important chemical signature for bacterial endospores such as anthrax. However, the fluorescence emission spectrum for DPA is broad, making it difficult to identify in the presence of other naturally occurring fluorophores. It has recently been shown that the quantum confined Stark effect, when applied to organic, fluorescent molecules in a nanowire configuration, induces a molecule-specific shift in the peak wavelength of the emission spectrum. In addition, for some molecules, a molecular prism effect has been induced, whereby the normally featureless emission spectrum of a fluorescent molecule is split into distinct, equally spaced energy lines. In addition to the application in biosensing, the proposed research project will have broad impact in various other technological areas. For example, the ability to selectively tune the peak emission wavelength in organic fluorophores may be used to develop new optical displays with adjustable emission properties or new tunable optical filters for wavelength selection. In addition, a general understanding of the quantum confined Stark effect applied to organic fluorescent molecules could lead to a wide variety of new discoveries in areas ranging from energy harvesting to DNA labeling.