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

Development of nitrogen and fluorine-doped carbon dots (N, F-CDs) as fluorescent sensor for detection of Fe³⁺ ions in the water environment

Dyah Sarsiwi Hamurwani, Kurniawati Auliyah Obbyardi, Mudasir Mudasir, and Suherman Suherman

Department of Chemistry, Faculty of Mathmematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta, Indonesia

E-mail: suherman.mipa@ugm.ac.id

Received: 15 July 2025  Accepted: 5 February 2026

Abstract:

Nitrogen and fluorine doped carbon dots (N, F-CDs) were synthesized via microwave-assisted heating using citric acid and ammonium fluoride. Optimum conditions (450 W, 80 s, 50 mg dopant) produced N, F-CDs with strong fluorescence intensity. FTIR confirmed the presence of N–H, C–N, and C–F functional groups, while TEM revealed quasi-spherical particles with an average size of 1.67 ± 0.25 nm. The optimized N, F-CDs exhibited stable fluorescence across pH 4–9, under 90 min UV exposure, and after 7 days of storage at 4 °C. Selectivity tests demonstrated pronounced fluorescence quenching in the presence of Fe³⁺ ions with minimal interference from other metal ions. The sensor achieved a detection limit of 0.0087 ppm and a quantification limit of 0.0291 ppm. Application to environmental water samples demonstrated high accuracy and precision, with RSD values below 5%. These findings indicate that optimally synthesized N, F-CDs are a reliable and sensitive fluorescent nanosensor for Fe³⁺ monitoring in water environments.

Graphical abstract

Keywords: Carbon dots; Fe3+; Fluorescent sensor; Nitrogen; Fluorine

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04731-7

Chemical Papers 80 (5) 5599–5613 (2026)