Journal Article


Dermot Brabazon
Pleun Maaskant
Mahbub Akther
Marketa Vaculovicova



materials optical fibre capillary electrophoresis fluorescence detection micro light emitting diode array light source mechanical engineering separations

Fibre coupled micro-light emitting diode array light source with integrated band-pass filter for fluorescence detection in miniaturised analytical systems (2015)

Abstract In this work, a new type of miniaturized fibre-coupled solid-state light source is demonstrated as an excitation source for fluorescence detection in capillary electrophoresis. It is based on a parabolically shaped micro- light emitting diode (µ-LED) array with a custom band-pass optical interference filter (IF) deposited at the back of the LED substrate. The GaN µ-LED array consisted of 270 individual µ-LED elements with peak emission at 470nm, each about 14µm in diameter and operated as a single unit. Light was extracted through the transparent substrate material, and coupled to an optical fibre (400µm in diameter, numerical aperture NA = 0.37), to form an integrated µ-LED-IF-OF light source component. This packaged µ-LED-IFOF light source emitted approximately 225µW of optical power at a bias current of 20mA. The bandpass IF filter was designed to reduce undesirable LED light emissions in the wavelength range above 490 nm . Devices with and without IF were compared in terms of optical power output, spectral characteristics as well as LOD values. While the IF consisted of only 7.5 pairs (15 layers) of SiO2/HfO2 layers it resulted in an improvement of the baseline noise as well as the detection limit measured using fluorescein as test analyte, both by approximately one order of magnitude, with a LOD of 1×10-8 mol/L obtained under optimised conditions. The µ-LED-IF-OF light source was then demonstrated for use in capillary electrophoresis with fluorimetric detection. Limits of detection obtained by this device were compared to those obtained with a commercial fibre coupled LED device.
Collections Ireland -> Dublin City University -> Publication Type = Article
Ireland -> Dublin City University -> Status = Published
Ireland -> Dublin City University -> Subject = Engineering: Mechanical engineering
Ireland -> Dublin City University -> DCU Faculties and Centres = Research Initiatives and Centres: Advanced Processing Technology Research Centre (APTRC)
Ireland -> Dublin City University -> Subject = Engineering: Materials
Ireland -> Dublin City University -> DCU Faculties and Centres = Research Initiatives and Centres: Irish Separation Science Cluster (ISSC)

Full list of authors on original publication

Dermot Brabazon, Pleun Maaskant, Mahbub Akther, Marketa Vaculovicova

Experts in our system

Dermot Brabazon
Dublin City University
Total Publications: 162
Pleun P. Maaskant
University College Cork
Total Publications: 17