On-chip intermediate LED-IF-based detection for the control of electromigration in multichannel networks.
Monitoring analytes during the transfer step from the first to the second dimension in multidimensional electrophoretic separations is crucial to determine and control the optimal time point for sample transfer and thus to avoid band broadening or unwanted splitting of the sample band with consequent sample loss. A spatially resolved intermediate on-chip LED-induced fluorescence detection system was successfully implemented for a hybrid capillary-chip glass interface. The setup includes a high-power 455-nm LED prototype as an excitation light source and a linear light fiber array consisting of 23 light fibers with a diameter of 100 μm for spatially resolved fluorescence detection in combination with a push-broom imager for hyperspectral detection. Using a basic FITC solution, the linear working range was determined to be 0.125 to 25 μg/ml for a single light guide and the absolute detection limit was 0.04 fmol at a signal-to-noise ratio of 4. With the setup presented here, labeled β-lactoglobulin focused via capillary isoelectric focusing was detectable on-chip with a sufficient intensity to monitor the analyte band transfer in the glass-chip interface demonstrating its applicability for full or intermediate on-chip detection.
Institute of Physical and Theoretical Chemistry, Faculty of Science, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
Daniel
D
Sydes
Institute of Physical and Theoretical Chemistry, Faculty of Science, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.|CIMEC, Centro de Investigación de Métodos Computacionales (UNL-CONICET), 3000, Santa Fe, Argentina.
Pablo A
PA
Kler
J&M Analytik AG, Willy-Messerschmitt-Straße 8, 73457, Essingen, Germany.
Hans
H
Meyer
Optoelectronics and Laser Technology Department, University of Applied Sciences Aalen, 73430, Aalen, Germany.
Peter
P
Zipfl
CalvaSens GmbH, Ulmer Str. 126, 73431, Aalen, Germany.
Daniel
D
Lutz
Institute of Physical and Theoretical Chemistry, Faculty of Science, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany. carolin.huhn@uni-tuebingen.de.
Carolin
C
Huhn
D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D046209:Electrophoresis, Microchip / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D007525:Isoelectric Focusing / Q000295:instrumentation / Q000379:methods*; D007782:Lactoglobulins / Q000737:chemistry / Q000302:isolation & purification*; D012996:Solutions / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling / Q000379:methods
D005456:Fluorescent Dyes; D007782:Lactoglobulins; D012996:Solutions; D016650:Fluorescein-5-isothiocyanate
Glass microchip; Isoelectric focusing; On-chip LED-IF detection; Two-dimensional separations; Voltage switching