MWCNT-coumarin hybrids as fluorescence sensors for selective Fe³⁺ detection: investigating roles of MWCNT characteristics via synthesis and functionalization
Issued Date
2026-03-01
Resource Type
ISSN
24680230
Scopus ID
2-s2.0-105029304991
Journal Title
Surfaces and Interfaces
Volume
84
Rights Holder(s)
SCOPUS
Bibliographic Citation
Surfaces and Interfaces Vol.84 (2026)
Suggested Citation
Vettavong T., Thepmongkorn W., Wangngae S., Thisan S., Jarisarapurin W., Kumphune S., Masrinoul P., Ruangdachsuwan S., Inthapat P., Chotmunkhongsin C., Chaiwat W., Sutthasupa S. MWCNT-coumarin hybrids as fluorescence sensors for selective Fe³⁺ detection: investigating roles of MWCNT characteristics via synthesis and functionalization. Surfaces and Interfaces Vol.84 (2026). doi:10.1016/j.surfin.2026.108604 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/114957
Title
MWCNT-coumarin hybrids as fluorescence sensors for selective Fe³⁺ detection: investigating roles of MWCNT characteristics via synthesis and functionalization
Corresponding Author(s)
Other Contributor(s)
Abstract
In this study, waste-derived benzene-toluene-xylene (BTX) mixtures were utilized as sustainable carbon feedstocks for surface-engineered nanomaterials. Pristine multi-walled carbon nanotubes (MWCNTs) with diameters of approximately 30 and 60 nm were synthesized using iron-based catalysts (Fe/Al₂O₃ and Fe/SiO₂), with commercial MWCNTs (∼10 nm in diameter) serving as benchmarks. The pristine MWCNTs were purified and functionalized through a one-pot acid treatment that simultaneously removed catalyst residues and introduced oxygen-containing surface groups, yielding high-purity functionalized MWCNTs (f-MWCNTs) with significant carboxyl content. Despite variations in nanotube diameter and purity, four f-MWCNT probes exhibited comparable selective fluorescence quenching toward Fe³⁺, with limits of detection (LODs) of 2.20–2.78 µM at probe concentrations of ∼2.0 µM. These results demonstrate that sensing performance is governed primarily by surface chemistry and interfacial interactions. Covalent conjugation of coumarin derivatives to the f-MWCNT surfaces further tailored the organic–inorganic interface, improving the LODs to 1.82–1.92 µM at a fivefold lower probe concentration (∼0.4 µM) by enhancing fluorescence emission and suppressing aggregation-induced quenching. The coumarin-conjugated f-MWCNTs showed low cytotoxicity, maintaining >90% cell viability at 0.1–10 µg/mL. This work establishes a scalable CNT-based hybrid platform in which controlled surface functionalization and interface design enable robust fluorescence sensing for biomedical and environmental applications.