Waveguide flow cell

Figure 22-24 Light path in an optical waveguide flow cell. Some cells now available have a 5-mm effective pathlength containing only 0.25 xL of liquid or a 10-mm pathlength with 1 jlL.

Sato S., Saito M. and Miyagi M., Infrared Hollow Waveguides for Capillary Flow Cells, Appl. Spectrosc., 1993 47 (10) 1665-1669. 

Luminescence core-based optodes have been reported as waveguide capillary flow cells in liquid-filled optical fibers [ 103] or with polymers attached to the inner surface of a glass capillary [104],... 

Zhang, J. Z. (2000). Shipboard automated determination of trace concentrations of nitrite and nitrate in oligotrophic water by gas-segmented continuous flow analysis with a liquid waveguide capillary flow cell. Deep Sea Res. 147, 1157—1171. 

Figure 12.28. Schematic of fluorocarbon waveguide for enhancing sensitivity of liquid and aqueous samples. May be used as a flow cell as shown in lower drawing. (Adapted from Reference 30 with permission.)...

FIGURE 6.17 Schematic representation of a long optical path flow cell. 1 = support 2 = coiled liquid core waveguide 3 = manifold tubing a and b = points for connecting optical fibres. For details, see text. 

Bruno, A. E., Gassmann, E., Pericles, N., and Anton, K., On-column capillary flow cell utilizing optical waveguides for chromatographic application, Anal. Chem., 61, 876, 1989. 

Wei X, Mares JW, Gao Y, Li D, Weiss SM (2012) Biomolecule kinetics measurements in flow cell integrated porous silicon waveguides. Biomed Opt Express 3(9) 1993-2003... 

The cleaned waveguides were assembled into the OWLS flow cell and equilibrated by exposing to HEPES buffer solution (10 mM 4-(2-hydroxyethyl)piperazine-l-ethanesulfonic acid (Sigma, St. Louis, MO, USA), adjusted to pH 7.4 with 6.0 M NaOH solution) overnight in order to obtain a stable baseline. The waveguides were then exposed to a polymer solution (0.25 mg mL in HEPES buffer) for at least 30 min, resulting in the formation of a polymer adlayer, and rinsed three times by soaking them in buffer solution for another 30 min. 

Serum-Adsorption Experiments Protein-resistance measurements were carried out by following the same procedure as above to form a PLL-g-PEG/PEG-NTA monolayer on the waveguide (or after the standard assay experiments of binding 6xHis-tagged proteins), and then the surface was fully regenerated by exposing it to EDTA (200 mM). After a flat baseline was reached, the control human serum was injected into the OWLS flow cell. After 15 min of equilibration, the flow cell was rinsed with HEPES-2 buffer and allowed to equilibrate for 30 additional minutes. The difference to the first baseline corresponds to the amount of non-specific adsorption of proteins. 

Figure 35. Principle of grating coupler [ 160] a) Grating b) Flow cell e) Carrier d) Waveguide...

L.J. Gimbert, P.M. Haygarth, P.J. Worsfold, Determination of nanomolar concentrations of phosphate in natural waters using flow injection with a long path length liquid waveguide capillary cell and soUd-state spectrophotometric detection, Talanta 71 (2007) 1624-1628. 

M.S.A.C. Neves, M.R.S. Souto, I.V. Toth, S.M.A. Victal, M.C. Drumond, A.O.S.S. Rangel, Spectrophotometric flow system using vanadomolybdophosphate detection chemistry and a liquid waveguide capillary cell for the determination of phosphate with improved sensitivity in surface and ground water samples, Talanta 77 (2008) 527-532. 

J. Ma, D. Yuan, M. Zhang, Y. Liang, Reverse flow injection analysis of nanomolar soluble reactive phosphorus in seawater with a long path length liquid waveguide capillary cell and spectrophotometric detection,... 

J. Avivar, L. Ferrer, M. Casas, V. Cerda, Automated determination of uranium(VI) at ultra-trace levels exploiting flow techniques and spectrophotometric detection using a hquid waveguide capillary cell. Anal. Bioanal. Chem. 397 (2010) 871-878. 

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