Insight into the Interaction between Selected Antitumor Gold(III) Complexes and Citrate Stabilized Gold Nanoparticles

This paper presents the study of the interaction between gold nanoparticles (AuNPs) and antitumor gold complexes, [Au(OH)2(bipy)][PF6], [Au(CH3COO)2(pydmb-H)], and [Au(bipydmb-H)(OH)][PF6], in order to estimate the possibility for metal complex tracking in cells using nanospectroscopy approach. Decrease of intensity of the surface plasmon absorption band at 524 nm and the appearance of a new broad band at ∼640 nm, followed by their red shift were observed in the presence of the complexes. TEM images showed that the average size and shape of AuNPs did not change after the addition of gold complexes. DLS and zeta potential measurements pointed out to the metal complex adsorption on the surface of AuNPs followed by flocculation process. In addition, kinetic studies indicated strong bond formation between these complexes and AuNPs. Accordingly, AuNPs/complex conjugates have the potential to be applied for the tracking of these metal complexes in the cells using nanospectroscopy approach.