Optical Fiber Microsensors for Monitoring Protein Crystal Growth

Intelligent Optical Systems (IOS), in collaboration with Dr. Alex McPherson and Dr. Stanley Koszelak of the University of California, Irvine, proposes to develop a family of unique sub-micron optical fiber sensors to monitor pH, temperature, and ionic strength during protein crystal growth. The proposed device combines an array of sub-micron tapered optical fibers with near?field optical (NFO) techniques and polymer-immobilized fluorescent indicators. The result is a versatile, self?referenced, multi-analyte, high-speed sensor that will be used to constantly monitor the parameters of a protein crystal growth (PCG) chamber during protein crystallization. Since small differences in pH, temperature, and ionic strength may affect the quality of the resulting crystals, it is highly desirable to monitor the solution parameters. However, because spaceborne crystal growth chambers are very small (on the order of tens of microliters), the measurement of these parameters requires the use of microscopic and sub-microscopic instrumentation that is not currently available. IOS proposes to develop a system capable of determining the influence of crystallization parameters on the size, quality, and growth rate of protein crystals in extremely small volumes. The resulting instrument will be compact enough to be used aboard space platforms, and will lead to a commercial product with medical and pharmaceutical applications.