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Detection of Single Molecules Illuminated by a Light-Emitting Diode
CQT, Centre for Quantum Technologies, 3 Science Drive 2, 117543, Singapore
Low Temperature Group, Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, B.C., V6T 1Z1, Canada
* Author to whom correspondence should be addressed.
Received: 8 December 2010; in revised form: 11 January 2011 / Accepted: 12 January 2011 / Published: 14 January 2011
Abstract: Optical detection and spectroscopy of single molecules has become an indispensable tool in biological imaging and sensing. Its success is based on fluorescence of organic dye molecules under carefully engineered laser illumination. In this paper we demonstrate optical detection of single molecules on a wide-field microscope with an illumination based on a commercially available, green light-emitting diode. The results are directly compared with laser illumination in the same experimental configuration. The setup and the limiting factors, such as light transfer to the sample, spectral filtering and the resulting signal-to-noise ratio are discussed. A theoretical and an experimental approach to estimate these parameters are presented. The results can be adapted to other single emitter and illumination schemes.
Keywords: single molecules; fluorescence microscopy; light-emitting diode; LED; signal to noise ratio; single photon detection
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Gerhardt, I.; Mai, L.; Lamas-Linares, A.; Kurtsiefer, C. Detection of Single Molecules Illuminated by a Light-Emitting Diode. Sensors 2011, 11, 905-916.
Gerhardt I, Mai L, Lamas-Linares A, Kurtsiefer C. Detection of Single Molecules Illuminated by a Light-Emitting Diode. Sensors. 2011; 11(1):905-916.
Gerhardt, Ilja; Mai, Lijian; Lamas-Linares, Antìa; Kurtsiefer, Christian. 2011. "Detection of Single Molecules Illuminated by a Light-Emitting Diode." Sensors 11, no. 1: 905-916.