Selective colorimetric sensing of Fe3+ by hesperetin-conjugated silver nanoparticles: further investigation of interaction properties with bovine serum albumin

Abstract

Hesperetin-conjugated silver nanoparticles (HSP-AgNPs) were prepared using hesperetin as a reducing and stabilizing agent. UV-Vis and FTIR spectroscopy, dynamic light scattering, XPS, XRD and HRTEM were used to confirm the formation of functionalized nanoparticles. HSP-AgNPs displayed notable sensitivity and selectivity in the detection of Fe³⁺ in water. The probe also exhibited strong anti-interference performance against other metal ions. A detection limit (LOD) of 0.41 µM suggested prospective application of HSP-AgNPs in environmental sensing of Fe³⁺. Further, to explore the potential of HSP-AgNPs in biosensing of Fe³⁺, the biodistribution of nanoparticles was checked by studying their interaction with bovine serum albumin (BSA), a model carrier protein. Interactions between BSA and HSP-AgNPs were explored using UV-Vis, steady-state, time-resolved and synchronous fluorescence spectroscopy. HSP-AgNPs caused static quenching of tryptophan fluorescence of BSA. The thermodynamic parameters of binding (ΔH and ΔS) suggested the predominant involvement of hydrophobic interactions between BSA and nanoparticles.