Quaternary ammonium poly(amidoamine) dendrimer stabilized gold and other metal nanoparticles for biosensor applications

Abstract

Quaternary ammonium poly(amidoamine) (PAMAM) dendrimer stabilized gold nanoparticles (QPAMAM-AuNPs) were prepared and used for fabrication of new GC-QPAMAM-AuNPs electrode and this in turn was investigated for sensing of trace quantity of H2O2. Further, the QPAMAM-AuNPs were inspected for catalysis of nitrobenzene. Initially, amine-terminated PAMAM dendrimer was neutralised by acetylation followed by quaternization reactions. This quaternized product was used as a template for stabilization of gold nanoparticles by conducting the reactions at room temperature and thus produced quaternized dendrimer stabilised gold nanoparticles labelled as QPAMAM-AuNPs. The synthesized QPAMAM-AuNPs were characterized by UV-Vis, FTIR, 1H NMR, MALDI-TOF and TEM analyses. This QPAMAM-AuNPs was coated on newly produced glassy carbon modified electrode without any binding agent, particularly any enzyme to produced GC-QPAMAM-AuNPs electrode. This newly fabricated electrode in turn were employed for detection and sensing of trace quantity of H2O2 and it is observed that the electrode has an ability to detect the H2O2 ranging from [100 µM] to [5 mM] in neutral pH. Similarly, it is also proved that QPAMAM-AuNPs has effectively reduced the nitrobenzene and the observed pseudo-first order rate constant was 25.25 ×10-3s-1. It is established that the stabilized nanoparticles are water-soluble and stable for three months. Copyright © 2017 VBRI Press.