Functionalization of attapulgite with fluorescent ortho-phenanthroline side-chain polymer for Cu(II) ion sensing and adsorption

A novel fluorescent chemosensor based on the ortho-phenanthroline side-chain polymer-modified attapulgite nanohybrid material (ATP-PR) was prepared. The resulting ATP-PR, extensively characterized, exhibited significant fluorescence quenching at 398 nm upon the introduction of Cu(II) ions in water. With a Cu(II) ion detection range of 0.01–0.12 mg/L, the nanosensor achieved a low limit of detection at 0.17 μmol/L and demonstrated resilience to interference from other ions. The observed fluorescence quenching is likely attributable to a static quenching mechanism, which forms a non-fluorescent coordination complex. The Cu(II) ion adsorption process followed pseudo-second kinetic and Langmuir isotherm models, with a high maximum adsorption capacity of 41.67 mg/g surpassing that of natural ATP. The surface-coating with o-phenanthroline side-chain polymer effectively enhanced ion adsorption. The nanohybrid displayed reproducibility for Cu(II) ion adsorption and elution using hydrochloric acid, showing promise for environmental Cu(II) ion sensing and remediation in water.