A compact, low-cost and high sensitive LIF based on pinhole metal-capillary and direct laser-diode excitation

Compact Fluorescence Spectrometer with Built-In In-Line Calibration: Application to Detect Dissolved Organic Matter in Water

“…As shown in Figure A, the MC is axially illuminated by an UV-LED (i.e., axial-excitation), and the generated fluorescence is guided along the capillary and then detected at the outlet of the capillary (i.e., axial-collection). The MC, ISCS, and photodetector were placed closely, so a high collection efficiency of the optical signal between the MC and photodetector of the ISCS-FS apparatus can be realized. , When the ISCS (including the TEP filter and LVF) is moved in front of the photodetector, the TEP signal and fluorescence spectrum can be scanned in sequence. Finally, in order to avoid the saturation of the photodetector (fW sensitivity), the TEP was attenuated by a long-pass filter at the MC outlet (Figure A) and a neutral density filter (attached on the TEP filter in ISCS) with an attenuation coefficient of ∼10 4 and ∼20, respectively…”

“…In our previous report, , a metal capillary (MC)-based LIF (i.e., MC-LIF) with 520 nm laser (or 310 nm LED) excitation was proposed for enhancing the excitation and collection efficiencies. However, for the proposed MC-LIF, only the fluorescence intensity was measured, and spectral detection (especially spectral calibration) has not been realized.…”