Qinchao Shao,Xiubin Zhang,Pei Liang,Qiang Chen,Xiaohua Qi,Mingqiang Zou
Fabrication of a magnetic substrate based on metal–organic frameworks (MOFs) with high sensitivity and stability for surface-enhanced Raman scattering (SERS) analysis were reported in this paper. MIL-101(Cr) nanoparticle prepared via a traditional hydrothermal reaction, which was combined with Fe 3 O 4 to synthesize the Fe 3 O 4 /MIL-101(Cr) composites. Then, the concentration of chloroauric acid and the time of reduction reaction were adjusted to acquire the optimal Au/Fe 3 O 4 /MIL-101(Cr) (AF-MIL) SERS substrate. The detection ability of the substrate can down to 10 -8 mol/L for Rhodamine 6G (R6G) as probe molecule, and the relative standard deviation (RSD) is only about 4.48 %, which indicates that it possesses wonderful SERS performance and uniformity. Finally, the as-synthesized substrate has been adopted to test the trace level sulfapyridine, with its desirable detection ability can down to 10 -6 mol/L. Such desirable SERS substrate with facile and effective operation holds great promise in the fast sensitive detection of the antibiotic residue and some other pollutants in environment.
Background Phthalate acid esters (PAEs) are endocrine-disrupting contaminants that require reliable trace-level monitoring in environmental waters. Magnetic dispersive solid-phase extraction (MDSPE) offers a green sample-preparation approach, but its performance is often constrained by the limited adsorption capacity, poor structural integrity, limited reusability, and high material cost of existing sorbents. Developing a stable, magnetically responsive, and high-affinity nanocomposite to overcome these limitations remains a critical challenge. Results A novel ternary magnetic MWCNTs@Fe 3 O 4 @MIL-101(Fe) nanocomposite was successfully synthesized via a facile hydrothermal strategy, where multi-walled carbon nanotubes (MWCNTs) serve as a conductive scaffold intertwining Fe 3 O 4 nanoparticles and MIL-101(Fe) crystals. This unique architecture endows the sorbent with high saturation magnetization (58.9 emu/g) for rapid separation, a large specific surface area (1127.28 m 2 /g), and abundant π-electron-rich sites for enhanced adsorption. Under optimized MDSPE conditions coupled with gas chromatography-flame ionization detection (GC-FID), the method achieved wide linear ranges (0.05-2500 μg/L), ultra-low limits of detection (0.005-0.05 μg/L), and satisfactory absolute recoveries (89.5%-110.6%) in real environmental water samples. The sorbent exhibited good reusability (≥90% after five cycles) and excellent precision (RSDs <9.0%). Greenness assessment using the AGREE metric yielded a score of 0.65, reflecting a moderate-to-high level of environmental sustainability. Significance and novelty This work presents a novel “MWCNT-bridged” strategy that successfully integrates magnetic responsiveness, high porosity, and π-π interaction sites into a single, stable sorbent, resolving the common trade-off between functionality and recoverability in magnetic MOF composites. The rationally designed nanocomposite provides a robust, highly sensitive, and environmentally sustainable platform for monitoring trace PAEs in complex aqueous matrices, advancing the development of functional materials for green analytical chemistry.
危险品化学品经营许可证（带存储）