Turn-on fluorescent detection of Cd2+ by a naphthalene-derived Fe3O4@Schiff-base hybrid nanosensor with fast response and paper-strip readout
Microchemical Journal, cilt.229, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 229
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.microc.2026.119507
- Dergi Adı: Microchemical Journal
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Chimica, Index Islamicus, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Cadmium detection, Fe3O4 hybrid, Naphthalene Schiff base, Paper-based sensor, Real sample, Turn-on fluorescence
- Karadeniz Teknik Üniversitesi Adresli: Evet
Özet
Cadmium (II) is among the most toxic heavy metals that accumulate in aquatic and biological systems, posing serious risks to environmental and public health. Hence, the development of reliable, rapid, and selective analytical strategies for Cd2+ detection remains a critical challenge. In this study, a novel turn-on fluorescent nanosensor based on a naphthalene-derived Fe3O4@Schiff-base hybrid (Fe3O4@NSB) was designed and synthesized for the spectrofluorimetric determination of Cd2+ ions. The hybrid material was thoroughly characterized by FT-IR, XRD, TGA, SEM, and TEM analyses, confirming the successful surface functionalization without structural degradation of the Fe3O4 core. The as-prepared nanosensor exhibits weak native emission due to photo-induced electron transfer (PET) from the π-conjugated ligand framework to the azomethine (C=N) site, which is efficiently suppressed upon Cd2+ coordination. Under optimized conditions (pH 8.0, λex = 270 nm, λem = 308 nm), the system displayed a pronounced fluorescence enhancement proportional to Cd2+ concentration in the range of 1.5–46.0 μM, with a low detection limit of 0.42 μM and excellent precision (RSD = 2.12%). The sensor demonstrated high selectivity toward Cd2+ over a variety of competing metal ions and biomolecules. Real-sample analyses in river and seawater provided recovery values between 94.95% and 104.45%, showing strong agreement with ICP-MS results. Furthermore, a paper-based test strip incorporating Fe3O4@NSB enabled a distinct visual turn-on response toward Cd2+, indicating its potential for on-site environmental monitoring.