Micro-interferometric backscatter detection using a diode laser

Swinney, Kelly; Markov, Dmitry A.; Hankins, Joseph; Bornhop, Darryl J.

doi:10.1016/s0003-2670(99)00627-3

Cited by 14 publications

(23 citation statements)

References 33 publications

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“…Just as important, it has been shown previously that when a nonoptically active solute is introduced, the intensity of the HF fringes remains unchanged or the contrast of the HF fringes is unaffected. 13,14 In general, a cross section of the backscatter fringe pattern is interrogated by evaluating differences in intensities of two pixels, a single pixel located at an HF fringe maximum and a single pixel associated with the adjacent minimum, normalized as a percentage of the m aximum intensity (Fig. 3B).…”

Section: Resultsmentioning

confidence: 99%

D-β-Hydroxybutyrate Reaction Kinetics Studied in Nanoliter Volumes Using a Capillary Polarimeter

Swinney

Bornhop

2000

Appl Spectrosc

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A laser-based capillary polarimetric detector (CPD) has been configured to allow for the analysis of optically active molecules at physiological temperatures and within a 40 nL sample volume. In the CPD, interference fringes contained within a 360° fan of scattered light result from the interaction between a polarized laser beam and a 240 μm i.d. capillary tube. Here it is shown that these fringes change in a reproducible manner with solute optical activity, facilitating a 3σ detection limit of 1.7 × 10−3 M d-β-hydroxybutyrate corresponding to 68 × 10−12 mole (7 × 10−9 gram) of solute. Further, with the use of this improved and novel polarimeter, the noninvasive study of enzyme reaction kinetics for d-β-hydroxybutyrate (50 mg/dL) and hydroxybutyrate dehydrogenase (100 μL of 50 units/L) has been evaluated for the first time in the absence of NAD. The rate constant for this reaction was found to follow first-order kinetics and determined to be 2.2 × 10−2 s−1. The prospect of directly studying the influence of enzyme cofactors on reaction kinetics is at hand, and the observations presented suggest that the application of monitoring insulin therapy for patients experiencing ketoacidosis is a tractable problem for the CPD.

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Section: Resultsmentioning

confidence: 99%

D-β-Hydroxybutyrate Reaction Kinetics Studied in Nanoliter Volumes Using a Capillary Polarimeter

Swinney

Bornhop

2000

Appl Spectrosc

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“…Firstly they reported back-scattered laser-based refractive index detection, 13 applied it to capillary electrophoresis, [14][15][16] and then realized back-scattered laser-based refractive index detection for chip electrophoresis. Since then, Bornhop's group have reported a series of researches on backscattered laser-based refractive index detection.…”

Section: Back-scattered Laser-based Refractive Index Detectionmentioning

confidence: 99%

“…Since then, Bornhop's group have reported a series of researches on backscattered laser-based refractive index detection. Firstly they reported back-scattered laser-based refractive index detection, 13 applied it to capillary electrophoresis, [14][15][16] and then realized back-scattered laser-based refractive index detection for chip electrophoresis. 17,18 Moreover, this group utilized the backscattered laser-based refractive index detector for ultra-small diameter capillaries, which changed the evidence that refractive index detection could only be applied to large diameter capillaries.…”

Section: Back-scattered Laser-based Refractive Index Detectionmentioning

confidence: 99%

Laser-based refractive index detection for micro-channels

Xiong

2011

Analyst

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Laser-based refractive index detection, based upon refractive index changes in micro-channels, is a kind of laser-based optical determination for solutions. As it is capable of label-free determination, it has been regarded as a considerable growth prospect. The key aspect in related researches lay in the development of novel detection configurations, which would possibly result in better sensitivity. Over the past decade, micro-channel laser-based refractive index detection has been significantly improved, resulting in traversed, hologram-based, back-scattered, retro-reflected interference, optical ring resonant, etc., detection configurations. Moreover, laser-based refractive index detection has been combined with other laser-based detection strategies, in order to pursue a universal and sensitive detection. And last but not least, some utilizations of laser-based refractive index detection have been reported, while both advantages and drawbacks exist. In this paper, laser-based refractive index detection for micro-channels will be reviewed in proceeding sequence.

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“…[xli] Detection of optical rotation, α, by laser optical methods and flow techniques is adaptable to HPLC for on- the-fly characterization of chiral molecules. [xlii],[xliii]. Circular dichroism (CD) is observed when circularly polarized light (CPL) passes through a solution of a chiral, optically active compound whose molecular structure contains a chromophore.…”

Section: Chiroptical Techniques: Circular Dichroism and Absolute Cmentioning

confidence: 99%

Microscale methodology for structure elucidation of natural products

Molinski

2010

Current Opinion in Biotechnology

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1. Summary of Recent Advances Advances in microscale spectroscopic techniques, particularly microcryoprobe NMR, allow discovery and structure elucidation of new molecules down to only a few nanomole. Newer methods for utilizing circular dichroism (CD) have pushed the limits of detection to picomole levels. NMR and CD methods are complementary to the task of elucidation of complete stereostructures of complex natural products. Together, integrated microprobe NMR spectroscopy, microscale degradation and synthesis, are synergistic tools for discovery of bioactive natural products and have opened new realm for discovery among extreme sources including compounds from uncultured microbes, rare invertebrates and environmental samples.

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Micro-interferometric backscatter detection using a diode laser

Cited by 14 publications

References 33 publications

D-β-Hydroxybutyrate Reaction Kinetics Studied in Nanoliter Volumes Using a Capillary Polarimeter

D-β-Hydroxybutyrate Reaction Kinetics Studied in Nanoliter Volumes Using a Capillary Polarimeter

Laser-based refractive index detection for micro-channels

Microscale methodology for structure elucidation of natural products

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