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

Abstract

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⁺, Mn²⁺, Ca²⁺, Mg²⁺, Co²⁺, Zn²⁺, Cr³⁺, As³⁺, Fe²⁺, Hg²⁺, and Cu²⁺), anions (Cl⁻, CO₃²⁻, NO₃⁻, and NO₂⁻), 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.