Antioxidant flavone functionalized fluorescent and biocompatible metal nanoparticles: Exploring their efficacy as cell imaging agents

Abstract A synthetic fluorescent antioxidant flavone analog, 4′- N,N -dimethylamino-3-hydroxy flavone (DMAHF) was successfully explored as the green multifunctional agents for the synthesis of stable monometallic Au and Ag and bimetallic Au/Ag alloy nanoparticles with tailor-made morphologies. The synthesis of these nanoparticles were done in three types of surfactants e.g. sodium dodecyl sulfate (SDS), polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB). In addition to DMAHF itself, these surfactants have a pronounced effect on the morphology and surface chemistry of these nanoparticles. DMAHF has high fluorescent activity and it is a potent antioxidant. It imparted its characteristic fluorescence and antioxidant activities to these nanoparticles. At the same time these fluorescent and antioxidant nanoparticles were biocompatible as evidenced from their cytotoxicity assays on normal lung cell (L132). These nanoparticles also showed selective colorimetric sensing activity towards thiol containing amino acids, like cysteine and glutathione. The fluorescence activity of these biocompatible nanoparticles was further utilized for the cell imaging process. In future these nanoparticles can be used as the fluorescent probes for biomolecules in living systems.