A portable low-cost fluorimeter based on LEDs and a smart phone

Abstract

This article presents a simple self-constructed fluorimeter aimed at both in-field analyses and pedagogical purposes. An array of light emitting diodes (LEDs) comprises the emission source of the fluorimeter, providing desired wavelengths. The wavelength selection was achieved by turning on the LED(s) of suitable emission wavelength, which was performed easily by a simple electronic board. An omnipresent smart phone equipped with a freely available color digitizer app, played the fluorescence detector role. The emitted fluorescence, received by the phone’s camera, resulted in a digital image, which was decomposed into the primary colors by the digitizer app. This results in red (R), green (G), and blue (B) color channels expressed quantitatively as digital numbers, and among them, one is chosen as the analytical signal. The applicability of the constructed instrument was confirmed by comparing its analytical results with those of a commercial spectrofluorimeter. Riboflavin was used as an illustrative analyte and its standard solutions and real samples were analyzed by both the self-constructed and the commercial instrument. The results obtained by the designed fluorimeter were consistent with those obtained by the commercial instrument.