Assembling patchy plasmonic nanoparticles with aggregation-dependent antibacterial activity

Abstract

We realise an antibacterial nanomaterial based on the self-limited assembly of patchy plasmonic colloids, obtained by adsorption of lysozyme to gold nanoparticles. The possibility of selecting the size of the assemblies within several hundred nanometres allows for tuning their optical response in a wide range of frequencies from visible to near infrared. We also demonstrate an aggregation-dependent modulation of the catalytic activity, which results in an enhancement of the antibacterial performances for assemblies of the proper size. The gained overall control on structure, optical properties and biological activity of such nanomaterial paves the way for the development of novel antibacterial nanozymes with promising applications in treating multi drug resistant bacteria.

Unveiling the interaction of protein fibrils with gold nanoparticles by plasmon enhanced nano-spectroscopy

“…The electrostatic properties are mainly determined by amino acids with charged residues, namely amines and carboxylic groups. Lysozyme is one of the proteins with the highest isoelectric point occurring at pH 11.3 31,43 Due the protonation of most amine groups in the fibrillation at pH 2, it has a clearly positive net charge.…”

“…Moreover, lysozyme fibrillation has already been characterised by optical and near-field microscopies as well as with conventional spectroscopic techniques 28,29 . AuNPs are currently broadly tested in nanomedicine due to their good biocompatibility and their flexible optical properties which make them well-suited for chemical sensing and drug delivery [30][31][32] In the present contribution, complementary TERS and SERS experiments were performed as sketched in Fig. 1.…”

Exploiting SERS sensitivity to monitor DNA aggregation properties

“…Indeed, despite the higher stability of the chemically prepared silver colloids, a partial aggregation is necessary for them to become SERS-active and to create the hot-spots necessary for a high signal enhancement. This aggregation leads to the coupling between the localized plasmonic modes of the single NPs, resulting in the frequency shifts of the localized surface plasmon resonance (LSPR) of the aggregated system towards higher wavelengths [54,55], implying the use of a red laser.…”

Antibacterial Properties of Functionalized Gold Nanoparticles and Their Application in Oral Biology

“…Brasili et al adsorbed lysozyme onto gold nanoparticles and performed self-limiting assembly based on plaque-like plasmon colloids, thereby obtaining a new type of antibacterial nanomaterial. It has also been proved that the change of its catalytic activity will lead to the enhancement of the antibacterial performance of the appropriately sized components [78].…”