Electrochemistry on alternate structures of gold nanoparticles and ferrocene-tethered polyamidoamine dendrimers

Abstract

Self-assembled systems with polyamidoamine (PAMAM) dendrimers combined with gold nanoparticles have been widely studied because of their potential applications in molecular electronics, catalyst carriers, chemical sensors, and biomedical devices. In our work, gold nanoparticle monolayers and multilayers with pure and ferrocene-tethered PAMAM dendrimers as cross-linking molecules were deposited on a mixed self-assembled monolayer of gold substrates. The various generations of PAMAM dendrimers can be covalently attached to mercaptoundecanoic acid mixed with a mercaptoundecanol self-assembled monolayer. Cyclic voltammograms show that redox peak currents on the alternate multilayers of gold nanoparticles and ferrocene-tethered PAMAM dendrimers increase as the number of layers increases. Fourier transform IR external reflection spectroscopy and scanning electron microscopy support the results from electrochemical measurements.