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

Chromotropic acid-activated silver nanoparticles: a convenient colorimetric sensor for selective determination of divalent and trivalent iron ions

Nam-Phuong Nguyen-Huynh, Hong-Phuong Phan, Hoa-Hung Lam, Thi-An-Sa Do, Phuc-Thanh-Duy Nguyen, Thi-Kieu-Anh Tran, Antonio Reina, and Trung Dang-Bao

Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City, Vietnam

E-mail: dbtrung@hcmut.edu.vn

Received: 27 September 2024  Accepted: 2 June 2025

Abstract:

Iron ions play a crucial role in various biological, environmental, and industrial processes, making their quick and on-site detection in aqueous solutions a significant analytical challenge. This study presents a simultaneous colorimetric detection method for Fe(II) and Fe(III) ions in aqueous solutions using silver nanoparticles (AgNPs) functionalized with chromotropic acid (CTA). The detection of Fe(II) and Fe(III) ions based on CTA-AgNPs was monitored both visually and through ultraviolet–visible spectrophotometry (UV–vis). We discover a variation in nanoparticles size and absorption with their interaction with different ions, which allow us to determine analytical parameters such as the detection and quantification limits. This colorimetric system showed excellent selectivity to the detection of Fe(II) and Fe(III) ions, even in the presence of other metal cations that could potentially interfere the analysis. This approach offers a robust and efficient method for detecting iron ions, with potential applications in environmental monitoring and industrial processes.

Keywords: Silver nanoparticles; Chromotropic acid; Colorimetric sensor; Fe(II) ions; Fe(III) ions

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04180-8

Chemical Papers 79 (9) 6147–6158 (2025)