ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A novel optical chemical sensor for determination of selenium in food, water and biological samples

Alaa S. Amin, Mostafa Y. Nassar, and Hesham H. El-Feky

Chemistry Department, Faculty of Science, Benha University, Benha, Egypt

E-mail: asamin2005@hotmail.com

Received: 23 October 2025  Accepted: 22 December 2025

Abstract:

An optical chemical sensor membrane for selenium detection was formulated by incorporating the compound 8-[(E)-(3-chloro-5-methylpyridin-2-yl)diazenyl]-7-hydroxy-4-methyl-2H-chromen-2-one (CMDHMC) into a cellulose triacetate (CTA) matrix plasticized with tri-(2-ethylhexyl) phosphate (TEHP). Different formulations of CMDHMC embedded within TEHP-plasticized CTA matrices were investigated to achieve the optimal composition and it was discovered that no additional extractant was necessary, as the membrane exhibited a distinct color shift upon interaction with Se(IV) ions. Upon adsorbing selenium (IV) into the membrane, CMDHMC induced a pronounced color alteration from orange to pink, having a peak absorbance (λ_max = 546 nm) within 5.0 min of total equilibration at pH = 3.75. The synthesized membrane in the proposed procedure was represented for the Se(IV) analytical detection in water-based samples through both spectrophotometric techniques and flame atomic absorption spectrometry (FAAS). The preconcentration procedure exhibited a linear response at λ_max = 546 nm, corresponding to Se(IV) concentrations of 15–230 ng mL^–1 with a 250 preconcentration factor. Additionally, aqueous samples were analyzed via FAAS both prior to and following interaction with the membrane, demonstrating a consistent linear response within the 75–2000 ng mL^–1 concentration interval for Se(IV) ions. The detection and quantification limits, defined as 3 σ_sβ/S, and 10 σ_sβ/S, were 4.5 and 15 ng mL^–1 using colorimetry, whereas, for the FAAS method, 22.5 and 75 ng mL^–1 were obtained, respectively. The sensor membrane demonstrated reversible behavior, allowing for desorption through equilibration with 0.05 M HNO₃. To assess its practical utility, the fabricated sensor was utilized for detecting Se(IV) in various real-world samples, including natural waters, soil, plant material, food, beverage, and cosmetic fortified with known concentrations of Se(IV) ions.

Keywords: Optical chemical sensor; Selenium determination; Colorimetric and FAAS; Food, water and biological analysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04617-0

Chemical Papers 80 (5) 5177–5194 (2026)