title: Thin-film polymer light emitting diodes as integrated excitation sources for microscale capillary electrophoresis.
abstract: We report the use of a thin-film polymer light emitting diode as an integrated excitation source for microfabricated capillary electrophoresis. The polyfluorene-based diode has a peak emission wavelength of 488 nm, an active area of 40 microm x 1000 microm and a thickness of similar 2 mm. The simple layer-by-layer deposition procedures used to fabricate the polymer component allow facile integration with planar chip-based systems. To demonstrate the efficacy of the approach, the polyfluorene diode is used as an excitation source for the detection of fluorescent dyes separated on-chip by electrophoresis. Using a conventional confocal detection system the integrated pLED is successfully used to detect fluorescein and 5-carboxyfluorescein at concentrations as low as 10(-6) M with a mass detection limit of 50 femtomoles. The drive voltages required to generate sufficient emission from the polymer diode device are as low as 3.7 V.
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington, London, UKSW7 2AZ.
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Edel
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Beard
authors.forename: Oliver
authors.initials: O
authors.lastname: Hofmann
authors.forename: John C
authors.initials: JC
authors.lastname: deMello
authors.forename: Donal D C
authors.initials: DD
authors.lastname: Bradley
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: deMello
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004581:Electronics / Q000295:instrumentation; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods; D005449:Fluorenes / Q000737:chemistry; D005453:Fluorescence; D008832:Microchemistry / Q000295:instrumentation* / Q000379:methods; D011108:Polymers / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D005449:Fluorenes; D011108:Polymers; C041509:fluorene