Smartphones app as portable colorimetric sensor for low-cost quantification of safranin dye in aqueous solutions

ABSTRACT. An android smartphone-based digital image colorimeter was proposed as a novel, fast, cheap, and portable colorimetric sensor for quantification of safranin in aqueous solutions via built-in-house light-boxes photography. Smartphone application known as RGB color detector app that uses an image-matching algorithm via using of take photo (TP) and live camera (LC) to analyze colorful solutions. The color values including red (R), green (G), and blue (B) parameters can be measured with the aid of the app and used for quantifying colorful solutions. The influence of various experimental factors has been optimized. Under optimal conditions, analytical curves were 1.0-10.0 and 2.0-30.0 µg/mL of safranin using G and B parameters, respectively. The obtained signal via the G channel also presented greater sensitivity and linearity, therefore preferred to be the best working channel. The obtained linear range, correlation coefficient, limit of detection, and limit of quantification were 1.00-10.00 µg/mL, 0.9889, 0.15 µg/mL, and 0.51 µg/mL via the GTP-25 method, and 1.00-10.00 µg/mL, 0.9961, 0.13 µg/mL, and 0.44 µg/mL via GLC-25 method, respectively. The proposed method was successfully applied for evaluation of the dye removal. Results were in good agreement with those recorded by UV-Visible spectrophotometer/reference method.   KEY WORDS: Smartphone, App, Portable, Colorimetric, Sensor, Safranin   Bull. Chem. Soc. Ethiop. 2023, 37(5), 1065-1080.                                                  DOI: https://dx.doi.org/10.4314/bcse.v37i5.1