Development of a Simple Fe(II) Ion Colorimetric Sensor from the Immobilization of 1,10-Phenanthroline In Alginate/Pectin Film

Nindya Tri Muliawati (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, 55281 Yogyakarta, Indonesia)
Dwi Siswanta (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, 55281 Yogyakarta, Indonesia)
Nurul Hidayat Aprilita (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, 55281 Yogyakarta, Indonesia)

Indonesian Journal of Chemistry
Vol 21, No 2 (2021)

An optical analytical sensor was proposed based on the complexation reactions of 1,10-phenanthroline derivative in aqueous solutions. This study aims to synthesize a metal ion sensor for detecting Fe(ll) ion from the immobilization of 1,10-phenanthroline compound in alginate/pectin film. This was carried out by characterizing the films using the Fourier-transform infrared spectrometry (FT-IR) and scanning electron microscope (SEM). The determination of the optimal condition for Fe(II) ion detection and validation of the parameters was conducted by measuring the absorbance of the films using a UV-Vis spectrophotometer. After the addition of Fe(II) ion, the color of the alginate/pectin-phenanthroline film changed from transparent yellow to orange-red, showing its potential as a visual colorimetric sensor for iron(II) ion. It was found that the optimum condition for Fe(II) ion sensing was at 513 nm after 2 min of detection at pH 2. The alginate/pectin-phenanthroline film had good linearity, precision, selectivity, and accuracy with a detection limit as low as 0.446 mg L–1, which was remarkable.