Raman sensitivity enhancement for aqueous protein samples using a liquid-core op

2019-06-29 13:04:02

cell noise Raman mu lysozyme

责任者: Pelletier, M.J.;Altkorn, R. 单位: Kaiser Optical, Inc., Ann Arbor, MI 48106, United States 来源出处: Analytical Chemistry,2001,73(6):1393-1397 摘要: We have demonstrated a sensitivity enhancement factor of 500 in aqueous Solutions using a liquid core optical fiber (LCOF) Roman cell made from Teflon-AF. We were able to collect a spectrum of 54 μM lysozyme with a signal-to-noise ratio of 31 in the LCOF Raman cell using 24 mW of laser power and 3 min of integration time. The lysozyme Roman intensity was only 1% of the background Raman intensity from water, but the water-subtracted lysozyme spectrum was still shot-noise-limited and essentially free of nonrandom noise. The lack of nonrandom noise indicates that it should be possible to collect good quality Raman spectra of proteins such as lysozyme at even lower concentrations. The 2.4- μL sample volume of the LCOF Raman cell is an added benefit when limited quantifies of sample are available. This volume of a 54 μM lysozyme solution corresponds to only 13 nanomoles or 1.9 μg of lysozyme. 关键词: Biochemistry;Proteins;Optical fibers;Signal to noise ratio;Sensitivity analysis;Raman scattering;Sensitivity enhancement