A novel fluorescent probe, designated LXY, was designed and synthesized based on the rhodamine 6G scaffold to enable selective and sensitive detection of Fe³⁺ ions. The probe demonstrated remarkable performance in HEPES buffer (10 mM, pH = 7.4)/CH₃CN (2:3, v/v), where it exhibited a distinct color change from colorless to pink-red under visible light and a strong fluorescence emission at 550 nm under UV irradiation—enabling “naked eye” detection. This visual response is attributed to the structural transformation of the rhodamine moiety from a closed lactam ring (non-fluorescent) to an open form (fluorescent) upon coordination with Fe³⁺. The interaction mechanism was confirmed through Job’s plot analysis, mass spectrometry (MS), scanning electron microscopy (SEM), and X-ray single-crystal diffraction studies.CD56 Antibody Protocol Notably, while the crystal structure revealed the open-ring conformation of LXY induced by Fe³⁺, the metal ion itself was not detected in the lattice, suggesting a transient or non-stoichiometric binding mode. The limit of detection (LOD) for Fe³⁺ was determined to be as low as 3.Androgen Receptor Antibody Protocol 47 × 10⁻⁹ M, significantly below the WHO and EPA safety thresholds, highlighting its high sensitivity.PMID:34997187
Further validation was achieved through qualitative and quantitative assays using test papers, silica gel plates, and smartphone-based RGB analysis. The probe showed no interference from 18 other common metal ions including K⁺, Na⁺, Ca²⁺, Cu²⁺, Zn²⁺, Pb²⁺, and Hg²⁺, demonstrating excellent selectivity. A smartphone application utilizing RGB colorimetric analysis allowed real-time, on-site quantification of Fe³⁺ concentrations with a high correlation (R² = 0.97805) between R/B ratio and Fe³⁺ levels. Comparison with UV-Vis spectroscopy confirmed a low error rate of only 3.59%, affirming the reliability of the method. The probe also enabled effective solid-phase detection; when applied to silica gel plates, Fe³⁺-treated regions turned pink-red under ambient light and fluoresced strongly under UV light.
Biological imaging applications further underscored the practical utility of LXY. In plant tissues such as soybeans and *Erigeron annuus* roots, clear red/green fluorescence emerged after Fe³⁺ exposure, indicating successful penetration and signal generation within complex biological matrices. In *Caenorhabditis elegans*, weak background fluorescence was observed after LXY incubation, but intense fluorescence developed upon Fe³⁺ addition, confirming intracellular detection capability. In adult mice, systemic administration of LXY followed by Fe³⁺ injection led to specific fluorescence signals in vital organs—liver, kidney, and heart—while control animals showed no signal, proving in vivo biocompatibility and target specificity. These findings collectively demonstrate that LXY is a powerful tool for both environmental monitoring and biomedical diagnostics, offering rapid, selective, and sensitive Fe³⁺ detection across diverse systems.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
