Electrostatically mediated layer-by-layer assembly of a bioinspired thymine polycation and gold nanoparticles

GULOTTA, FLORENCIA A.; PAZ ZANINI, VERÓNICA I.; LÓPEZ DE MISHIMA, BEATRIZ A.; MARTINO, DÉBORA M.; LINAREZ PÉREZ, OMAR E.; FERREYRA, NANCY F.

JOURNAL OF ELECTROANALYTICAL CHEMISTRY - (Print)

ELSEVIER SCIENCE SA

Año: 2020 vol. 883

1572-6657

n this work, we built self-assembled structures of gold nanoparticles (AuNPs) using a new polyelectrolyte formed by copolymerization of the monomers 4-vinylbenzyl thymine (VBT) and 4-vinylbenzyl triethylammonium chloride (VBA). For the synthesis, a monomer ratio of 1 mol of VBT to 16 mol of VBA was used to obtain the polycation [(VBT)1:(VBA)16]16+ with a charge density suitable for the electrostatic adsorption of citrate stabilized AuNPs. The objective of this work was to explore the optical and electrochemical properties of the structure built on gold and quartz substrates with a view to its potential application as a (bio)sensor for optical and electrochemical detection. The polycation adsorption process was studied by surface plasmon resonance, which allowed us to select the appropriate concentration and adsorption time for the polymer and verify the formation of the self-assembly. Characterization of the system by atomic force microscopy allowed determining that AuNPs are distribu