Síntesis de biopelículas de almidón - hidrolato de cúrcuma para detección de hierro y cobre en soluciones acuosas.

Abstract

In this research, cassava starch biofilms impregnated with turmeric hydrolate were synthesized. This research focuses on the development of a biosensor for the detection of Fe+3 and Cu+2 cations in aqueous solutions. The starch extracted from cassava residues had a yield of 14.07 ± 0.70 %, with truncated ellipsoidal granules and a thermal decomposition temperature between 270.17 °C to 343.72 °C. Each biofilm (3.8±0.1 g) was made by mixing 4.87 % starch, 1.33 % glycerin, 90.68% water and 3.10% turmeric hydrolate. The biofilms obtained have a homogeneous distribution and thermal stability up to 262.31 °C. Turmeric hydrolate was extracted with 96 % ethanol, obtaining a dissolved weight percentage of 6.27 ± 0.80 %. Its chromatographic analysis showed that its major constituents are α-curcumene, curcumin, α-turmerone and β-sesquiphellandrene. The biofilms were impregnated with turmeric hydrolate, in which curcumin acts as a chromophore, forming complexes with metals and producing visible color changes, for the detection of the concentration by UV-vis spectroscopy of the Fe+3 and Cu+2 ions, 10 mm x 15 mm detection sheets are designed with an optical path of 12.83 mm x 5.13 mm. Spectrophotometric analysis was performed at 455 nm for iron and 430 nm for copper. The calibration curves (for both metals) showed exponential behavior for concentrations of 0, 3, 5, 7 and 10 ppm of both metals. This biosensor offers a sustainable and economical alternative to conventional methods, taking advantage of local resources and agricultural waste. The method provides rapid visual detection and spectrophotometric quantification, with potential application in environmental monitoring and field analysis.