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

Water-soluble chitosan-based fluorescent probe for Al³⁺ detection: synthesis and sensing performance

Habiba Zrida, Khaoula Hassine, Mariam Essid, and Khaled Hriz

Faculty of Sciences of Monastir, Laboratory of Interfaces and Advanced Materials (LIMA), University of Monastir, Board of the Environment, Monastir, Tunisia

E-mail: khaledhriz@gmail.com

Received: 31 December 2025  Accepted: 29 April 2026

Abstract:

Valorizing marine biowaste, this study reports the design of a novel water-soluble fluorescent chitosan derivative for Al³⁺ sensing. High-purity chitosan (97% DDA) extracted from shrimp shells was sequentially functionalized via a click chemistry and a Wittig reaction, introducing triazole and styrylanthracene fluorophore units to yield the Cs-Tri-An probe. A structural characterization (FT-IR, NMR) confirmed the successful synthesis and quantitative functionalization by Wittig reaction. Cs-Tri-An exhibits pronounced blue emission and organic semiconductor properties in aqueous solution. Its fluorescence sensing performance revealed a “turn-on” response toward Al³⁺, with a 31% enhancement. The probe forms a stable complex with Al³⁺ (binding constant K = 6.9 × 10⁴ M⁻¹) and achieves a nanomolar detection limit (LOD = 49.11 nM). These results demonstrate the successful modification of chitosan into a high-performance sensing material.

Keywords: Chitosan; Click chemistry; Water-soluble polymer; Optical properties; Fluorescent probe; Aluminum ion detection

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04978-0

Chemical Papers 80 (8) 9703–9714 (2026)