Description: In this Small Business Innovative Research (SBIR) effort, Leiden Measurement Technology LLC (LMT) proposes to design and build the Wholly-integrated Optofluidic Laser-induced Fluorescence Electrophoresis Chip (WOLFEChip) System, a microchip capillary electrophoresis (MCE) system using a miniaturized optofluidic approach for packaging all critical optical elements necessary for laser-induced fluorescence (LIF) on-chip. WOLFEChip uses cutting-edge laser micromachining to fabricate fully-three-dimensional optical elements that focus excitation laser light into a MCE microchannel to excite fluorescence. The fluorescence emission is collected using custom-designed high-numerical aperture collection optics immune to misalignment of the chip up to 1-mm. This improves on current and past implementations of MCE-LIF by (1) greatly miniaturizing the optical elements which comprise a significant amount of space in MCE-LIF systems; (2) making the entire LIF optical system monolithic and immune to misalignment which greatly enhances the vibration-resistance of the entire system; (3) making the system immune to operator-to-operator variations caused by the periodic need to carefully align traditional MCE-LIF systems; and (4) greatly reducing measured stray light and thereby potentially increasing the signal-to-noise ratio (SNR) of the MCE-LIF system by employing right-angle excitation/emission optical geometries and through the use of high-quality fluorescence-free fused silica. LMT will deliver a complete MCE-LIF system featuring a refined WOLFEChip design created in Phase I.

Benefits: WOLFECHip is especially well-suited for detecting life on Ocean Worlds in the solar system (e.g., Europa, Titan, Enceladus) as well as other smaller bodies (e.g., asteroids, comets) and rocky planets (e.g., Mars). For the detection of life, an unambiguous, highly-sensitive, definitive approach is required and MCE-LIF is an ideal technique for detecting life by measuring the relative abundance and chirality of amino acids and other important biomarkers. Key benefits of MCE-LIF for space exploration include: (1) its levels of detection are orders-of-magnitude lower than more traditional high-TRL gas chromatography approaches; (2) the technique uses minute volumes of reagents; (3) the instrumentation inherently requires very little power and mass; and (4) MCE-LIF is highly-suitable for dealing with liquid samples. WOLFEChip will be a great stride towards further miniaturizing and ruggedizing MCE-LIF hardware for upcoming mission opportunities by fully integrating the critical LIF optics on-chip thereby reducing mass, size, and the need for mechanical stability/alignment of external optical systems to micro-scale features.

WOLFECHip technology allows MCE-LIF systems to be ruggedized and maintained by less-skilled personnel and so has many uses outside of NASA. Due to its sensitivity, specificity, portability (both in terms of mass and ruggedness), and flexibility it can be used in many different situations including (1) environmental research of terrestrial and marine waters (e.g., detecting important biomarkers or nutrient sources); (2) process control and monitoring of closed water systems (e.g., Naval shipboard water monitoring, water treatment centers); (3) pharmaceutical research; (4) monitoring and identification of organic pollution in water, soils, and sediments (e.g., pesticides, fuels, drugs); (5) the detection of biological and chemical weapons. Advantages of WOLFEChip over existing electrophoresis technologies are its portability (enabled by its size and its rugged optofluidic implementation of LIF), resolution (MCE-LIF is inherently higher-resolution than CE due to the injected plug size), and operator-to-operator invariance (other MCE-LIF systems require an operator to manually align optics into a MCE chip, leading to LIF efficiencies varying based on the skill of the operator; WOLFEChip uses integrated optics to avoid this). In Phase III, LMT will seek to establish commercial relationships with vendors of MCE-LIF systems for marketing commercial-implementations of WOLFEChip to environmental scientists, water-quality monitoring authorities, and the United States Navy.