Structural, Morphological, Electrical, Magnetic, and dielectric properties of Zn0.5-xCa0.1Co0.4+xFe2O4 through the sol-gel method for flexible substrates in food chemical sensing
Md. Bakey Billa, Mohammad Tariqul Islam, Touhidul Alam, Iskandar Yahya, Ahmed Alzamil, Md. Shabiul Islam, Mohamed S. Soliman
Abstract
Food safety is a critical public health priority, as food chemicals such as formalin, saccharin, sucralose, and sodium benzoate present a significant health threat. A flexible substrate based on Zn-Ca-Co ferrite is proposed as a solution to food safety concerns, addressing limitations found in conventional microwave sensors. This study explores the possibilities of Zn0.5-xCa0.1Co0.4+xFe2O4 (x ranging from 0 to 0.30) nanoparticles synthesized by sol–gel as a flexible substrate, and a modified labyrinth-shape metamaterial structure reveals μ-negative characteristics from 7.084 to 7.48 GHz. The dielectric constant varied with composition, generating values of 1.34 to 1.84 for x values of 0.0 to 0.3. The sensor’s performance is assessed at various concentrations for each analyte, showing a clear link between chemical concentration and sensor response. The resonant frequency shift decreased as the analyte concentration increased, with formalin shifting from 110 MHz at 5 % to 40 MHz at 20 % and saccharin from 470 MHz at 25 % to 210 MHz at 33 % with notable sensitivity, ranging from 0.56 % to 7.01 %. The perceptible novelty of this study is that it introduces Zn-Ca-Co ferrite nanoparticles with enhanced magnetic and dielectric properties, designed for microwave sensing, and integrated into a flexible, μ-negative metamaterial for food safety applications.