Monolayer protected gold nanoparticles with metal-ion binding sites: functional systems for chemosensing applications

Abstract

In this review we describe the use of monolayer protected gold nanoparticles (Au NPs) for chemosensing applications. The attention is focused on a special subclass of Au NPs, namely those that contain binding sites for metal ions in the monolayer. It will be shown that these systems are very well-equipped for metal ion sensing as the complexation of the metal ions can affect the properties of the system in many ways leading to detectable output signals even at very low analyte concentrations. In addition, the presence of metal ions in the monolayer themselves can serve as recognition units for the highly selective interaction with small organic molecules or biomacromolecules. Key examples will be discussed that underscore the attractive properties and potential of this class of Au NPs as components of chemosensing assays.

Screen-Printed Electrodes Modified with Metal Nanoparticles for Small Molecule Sensing

“…Another advantage in the use of gold NPs consists in the strong binding of thiol ligands onto their surface due to the soft character of both gold and sulfur. Monolayers onto gold NPs were extensively used to stabilize them and also for functionalization purposes in many different applications [94].…”

Nanoparticle-Based Receptors Mimic Protein-Ligand Recognition

“…In a similar way to proteins, the large and organized chemical structure of the monolayer might result in the formation of binding sites in the nanoparticles, which can thereby selectively interact with other entities 19 . Thus, the ultimate goal is now the rational design of nanoparticle-based receptors with programmed selectivity and affinity 20 . To accomplish this, however, several crucial steps must still be taken, in particular, steps toward a deeper understanding of the process of molecular recognition within the nanoparticle-coating monolayer and of the parameters that control it.…”

Peptide‐Gold Nanoparticle Conjugates as Sequential Cascade Catalysts

“…In order to obtain such nanometer‐sized catalysts, termed nanozymes, different approaches have been reported including the application of metal‐organic‐frameworks, carbon‐based nanomaterials, different metal‐oxide‐based nanoparticles and noble‐metal nanoparticles, in particular those based on gold (Au−NPs) . Au−NPs have received considerable attention due to their biocompatibility,, tunable stability, and unique optoelectronic and catalytic properties, as well as their facile preparation and surface functionalization . The self‐assembly of thiolated‐ligands or cysteine‐containing peptides onto the surface of Au−NPs leads to dense functional monolayers that create novel, cooperative features and catalytic properties ,.…”