Multifunction Substrates for Laser Desorption Ionization

Lexitek and U. Mass Lowell propose to develop novel laser nanostructured substrates for laser desorption ionization (LDI) that enables mass spectrometry (MS) without an interfering chemical matrix. Lexitek is developing these patented plasmonic devices for molecular sensing using surface enhanced detection techniques. Using a technique invented by U. Mass researchers, the devices are fabricated in semiconductors or metals and consist of a semi-regular array of nanospikes that is subsequently metallized. The surface morphology and metal coating are tailored to optimize the interaction of the incident laser irradiation, the surface plasmons excited in the metal, and the analyte. Lexitek has developed proprietary technology for uniformly spotting the analyte onto the nanostructured surface. In Phase I, we will demonstrate a substrate for LDI that vaporizes analytes with minimal fragmentation. We will optimize the surface morphology and subsequent metallization for a single laser excitation wavelength using an existing MS instrument. In Phase II, we will construct a complete system for doing matrixless LDI and mass spec at multiple wavelengths. We will also develop several novel features of our substrate such as arrayed substrates, performing separation/fractionation in situ, and using soft nanolithography to replicate the nanostructures for very inexpensive substrates. BENEFIT: Our technology will enable very sensitive and specific detection of biomolecules and compounds, enabling a range of applications in biotechnology, clinical diagnostics, and research. The market for molecular diagnostics exceeds $6 billion, worldwide.