Portable and modularized fluorometer based on optical fiber

A portable and modularized fluorometer based on optical fiber was proposed in this work. The fluorometer included a light emitter diode (LED) light source module (LSM), a sample cell module (SCM), an optical-electrical converter module (OCM) and a signal process module (SAM). The LEDs in LSM were driven by a constant current source to provide stable exciting light with different wavelength. The OCM included a modularized optical filter and used a photomultiplier tube (PMT) to detect fluorescence signal. The SCM was used to locate sample cuvette and could be connected by optical fibers with the LSM and OCM. Via modularized design, the LSM and OCM could both selected and replaced based on different fluorescence dyes. In order to improve the detecting dynamic range of the fluorometer, the SAM could control the light intensity of LED source in LSM, to control the gain of PMT in OCM, and particularly, four channel signal acquisition circuits with different gain were constructed to collect fluorescence signal simultaneously. Fluorescein isothiocyanate (FITC) was selected as sample to test the fluorometer. The fluorometer has shown a high sensitivity with FITC concentration of 10ng/mL and presented a good linearity from 10 ng/mL to 10 μg/mL.