Selective colorimetric sensing of deferoxamine with 4-mercaptophenol- and mercaptoacetic acid-functionalized gold nanoparticles Fe() chelation

A gold nanoparticle-based colorimetric probe was developed for the determination of deferoxamine (desferrioxamine, DFO), a strong Fe( iii ) ion-chelator. Au-nanoparticles were synthesized and modified using 4-mercaptophenol (4MP) and mercaptoacetic acid (MAA) binders. The final probe was prepared by adding ferric ions to functionalized nanoparticles to form a coordination complex denoted as AuNPs@(4MP-MAA)/Fe( iii ), which enabled analyte detection via DFO-dependent nanoparticle aggregation and a colorimetric assay exploiting the SPR wavelength shift of the AuNPs. Structural analysis and interaction mechanism of the probe were elucidated using the ATR-FTIR, STEM, DLS, XRD, and XPS techniques. The detection and quantification limits (LOD and LOQ) for DFO in aqueous medium were found to be 27.0 nM and 90.0 nM, respectively. Common metal ions (Na + , Mn 2+ , Ca 2+ , Mg 2+ , Co 2+ , Zn 2+ , Cr 3+ , As 3+ , Fe 2+ , Hg 2+ , and Cu 2+ ), anions (Cl − , CO 3 2− , NO 3 − , and NO 2 − ), and biochemical species ( d -(+)-glucose, tryptophan, lysine, trypsin, dl -alanine, l -leucine, and glycine) were found not to significantly affect the sensor. Although the proposed method is based on the Fe( iii )-chelating ability of multidentate DFO, other simple Fe( iii ) chelators, such as 8-hydroxyquinoline, EDTA, sulfosalicylic acid, citric acid, and 1,10-phenanthroline, did not interfere. This LC-MS/MS-validated method was applicable to a commercial drug and fetal bovine serum as real samples. The multidentate deferoxamine ligand can selectively aggregate the Fe( iii )-attached AuNPs@(4MP-MAA) colorimetric nanoprobe, whereas other bidentate iron chelators cannot bridge the nanoparticles.