A collinear light-emitting diode-induced fluorescence detector for capillary electrophoresis.

A novel fluorescence detector based on collinear scheme using a brightness light-emitting diode emitting at 470nm as excitation source is described. The detector is assembled by all-solid-state optical-electronic components and coupled with capillary electrophoresis using on-column detection mode. Fluorescein isothiocyanate (FITC) and FITC-labeled amino acids and small molecule peptide as test analyte were used to evaluate the detector. The concentration limit of detection for FITC-labeled phenylalanine was 10nM at a signal-to-noise ratio (S/N) of 3. The system exhibited good linear responses in the range of 1x10(-7) to 2x10(-5)M (R(2)=0.999).