Selective Fluorescent Sensor Based on Coumarin–Cysteine-Polynorbornene for Sequential Cd2+and Anion Detection
Issued Date
2025-11-14
Resource Type
eISSN
26376105
Scopus ID
2-s2.0-105021881163
Journal Title
ACS Applied Polymer Materials
Volume
7
Issue
21
Start Page
14711
End Page
14729
Rights Holder(s)
SCOPUS
Bibliographic Citation
ACS Applied Polymer Materials Vol.7 No.21 (2025) , 14711-14729
Suggested Citation
Wangngae S., Thisan S., Kumphune S., Vettavong T., Thepmongkorn W., Chaiwat W., Sutthasupa S. Selective Fluorescent Sensor Based on Coumarin–Cysteine-Polynorbornene for Sequential Cd2+and Anion Detection. ACS Applied Polymer Materials Vol.7 No.21 (2025) , 14711-14729. 14729. doi:10.1021/acsapm.5c03037 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/113169
Title
Selective Fluorescent Sensor Based on Coumarin–Cysteine-Polynorbornene for Sequential Cd2+and Anion Detection
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Abstract
We report fluorescent, amino acid–based polymeric chemosensors, Poly-Cou-Cys, which were synthesized via ROMP using coumarin (Cou)-cysteine (Cys)-functionalized norbornene monomers. The resulting materials exhibit a selective Cd<sup>2+</sup>turn-off-turn-on response and subsequent anion recognition. Spectroscopic measurements were performed in DMSO solution (excitation = 350 nm, emission = 411 nm). The Cd<sup>2+</sup>turn-off mechanism relies on the Cd<sup>2+</sup>ion preferentially coordinating with the polymer’s soft sulfur donor atoms, along with other heteroatoms of coumarin and cysteine, leading to structural rigidification and fluorescence quenching. This mechanism was supported by<sup>1</sup>H NMR and ultraviolet–visible (UV–vis) spectroscopy. The limit of detection (LOD) for Cd<sup>2+</sup>was 55.10 nM (Polymer) and 41.94 nM (MWCNTs composite). The signal was restored (turn-on response) by biologically relevant anions: ATP, HS<sup>–</sup>, and H<inf>2</inf>PO<inf>4</inf><sup>–</sup>. This anion recognition mechanism operates by displacing the bound Cd<sup>2+</sup>ion. The most effective anions showed LOD values of 12.26 nM for ATP, 18.16 nM for HS<sup>–</sup>, and 13.41 nM for H<inf>2</inf>PO<inf>4</inf><sup>–</sup>. The probes demonstrated clear on–off-on fluorescence cycles in solution and on test strips. The systems also enabled Cd<sup>2+</sup>detection in artificial saliva. These results highlight the potential of this sensor for environmental Cd<sup>2+</sup>monitoring and for detecting clinically relevant anion biomarkers.