Attachment of gold nanoparticles on cellulose nanofibrils via click reactions and electrostatic interactions

Hybrid materials based on cellulose nanofibrils (CNF) and gold nanoparticles (AuNPs) are synthesized and novel routes to couple AuNPs on the CNF surface are introduced. Quaternary ammonium, azido, alkyne and amino functional groups were used for the attachment of metal particles on the corresponding functionalized CNF (EPTMAC-CNF, Azido-CNF, Propargyl-CNF, Amino-CNF, respectively). The CNF-based supports were characterized by Fourier transform infrared spectroscopy and the surface charge was assessed by ζ-potential measurements. The AuNPs were attached on the functionalized CNF surface via either electrostatic interactions or click reactions. The obtained CNF/AuNPs hybrid materials were characterized using transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectrometry. The obtained Bio-inorganic hybrid materials are potentially suitable for surface-enhanced Raman scattering, chemosensing and catalytic applications.