Chitosan-assisted self-assembly of flower-shaped ε-Fe 2 O 3 nanoparticles on screen-printed carbon electrode for Impedimetric detection of Cd 2+ , Pb 2+ , and Hg 2+ heavy metal ions in various water samples

• Published in: International journal of biological macromolecules 2024-04, Vol.265 (Pt 2), p.130867
• Main Authors: Singh, Diksha, Shaktawat, Sarita, Yadav, Surendra K, Verma, Ranjana, Singh, Kshitij Rb, Singh, Jay
• Format: Article
• Language: English
• ISSN: 1879-0003

This study focuses on the fabrication of a novel sensing platform on a screen-printed carbon electrode, modified by a combination of hydrothermally synthesized iron dioxide (ε-Fe O ) nanoparticles and Chitosan (CS) biopolymer. This unique organic-inorganic hybrid material was developed for Electrochemical Impedance Spectroscopy (EIS) sensing, specifically targeting heavy metal ions that include Hg , Cd , as well as Pb . The investigation encompassed a comprehensive analysis of various aspects of the prepared Fe O and CS/ε-Fe O nanocomposites, including phase identification, determination of crystallite size, assessment of surface morphology, etc. CS/ε-Fe O was drop-casted and deposited on the Screen-Printed Electrode (SPE). The resulting sensor exhibited excellent performance in the precise and selective quantification of Hg , Cd , and Pb ions, with minimal interference from other substances. The fabricated sensor exhibits excellent performance as the detection range for Hg , Cd , and Pb ions linearity is 2-20 μM, sensitivity, and LOD are 243 Ω/ μM cm and 0.191 μM, 191 Ω/μM cm , and 0.167 μM, 879 Ω/ μM cm , and 0.177 μM respectively. The stability of the CS/ε-Fe O /SPE electrode is demonstrated by checking its conductivity for up to 60 days for Hg , Cd , and Pb ions. The reusability of the fabricated electrode is 14 scans, 13 scans, and 12 scans for Hg , Cd , and Pb ions respectively. The findings indicate the successful development of an innovative CS/ε-Fe O electrode for the EIS sensing platform. This platform demonstrates notable potential for addressing the critical need for efficient and sensitive EIS sensors capable of detecting a range of hazardous heavy metal ions, including Hg , Cd , and Pb .