The present invention relates to a functionally integrated microanalytical system for performing fluorescence spectroscopy. A source of fluorescence-exciting radiation, typically a LED, is integrated onto a substrate along with a photodetector and, in some embodiments, an optical filter. A pixel-to-point laser lift-off process is used to effect this component integration. For those cases in which a filter is required, a thin film bandgap filter is typically used, such as CdS or CdSxSe1-x (0<x<1). A disposable microchannel containing the sample and its fluorescent tag is mounted onto the integrated assembly of LED, photodetector and (optionally) filter. This configuration of components allows the microchannel and sample to be readily removed and replaced, facilitating rapid analysis of multiple samples. Multiple LEDS, detectors and filters (if present) can also be integrated onto the same substrate, permitting multiple wavelength analysis of the sample to be performed concurrently.