Correction: Sophia, B.; et al. Presenting Precision Glycomacromolecules on Gold Nanoparticles for Increased Lectin Binding. Polymers 2017, 9, 716.

In the original version of this Article, an error occurred in the "Results and Discussion" section, under the subheading "Preparation and Characterization of Glyco-AuNPs"[...].

Synthesis and Optical Properties of Phenanthroline-Derived Schiff Base-Like Dinuclear RuII -NiII Complexes.

Two phenanthroline-derived Schiff base-like ligands with a covalently linked ruthenium(II) phosphorescent unit were synthesised and converted into bimetallic RuII -NiII complexes. The optical properties were studied to examine a possible photoluminescence quenching through a nonradiative energy-transfer upon a coordination-induced spin-state switch (CISSS) at the nickel(II) centre. Therefore, the metalloligands and the nickel(II) complexes were studied using UV/Vis absorbance, steady-state, and time-resolved emission spectroscopy in solutions of MeCN and pyridine. It is demonstrated that the nature of the bridging ligand between the ruthenium(II) donor and the nickel(II) acceptor strongly influences the photophysical behaviour upon CISSS. For the complex with a phenazine bridge, photoluminescence quenching is observed in the presence of a paramagnetic nickel(II) centre.

Presenting Precision Glycomacromolecules on Gold Nanoparticles for Increased Lectin Binding.

Glyco-functionalized gold nanoparticles have great potential as biosensors and as inhibitors due to their increased binding to carbohydrate-recognizing receptors such as the lectins. Here we apply previously developed solid phase polymer synthesis to obtain a series of precision glycomacromolecules that allows for straightforward variation of their chemical structure as well as functionalization of gold nanoparticles by ligand exchange. A novel building block is introduced allowing for the change of spacer building blocks within the macromolecular scaffold going from an ethylene glycol unit to an aliphatic spacer. Furthermore, the valency and overall length of the glycomacromolecule is varied. All glyco-functionalized gold nanoparticles show high degree of functionalization along with high stability in buffer solution. Therefore, a series of measurements applying UV-Vis spectroscopy, dynamic light scattering (DLS) and surface plasmon resonance (SPR) were performed studying the aggregation behavior of the glyco-functionalized gold nanoparticles in presence of model lectin Concanavalin A. While the multivalent presentation of glycomacromolecules on gold nanoparticles (AuNPs) showed a strong increase in binding compared to the free ligands, we also observed an influence of the chemical structure of the ligand such as its valency or hydrophobicity on the resulting lectin interactions. The straightforward variation of the chemical structure of the precision glycomacromolecule thus gives access to tailor-made glyco-gold nanoparticles (glyco-AuNPs) and fine-tuning of their lectin binding properties.

Fully Reversible Quantitative Phase Transfer of Gold Nanoparticles Using Bifunctional PNIPAM Ligands.

Ligand exchange with end-functionalized polymers is often applied to render nanoparticles with enhanced colloidal stability, to change the solubility in various environments, and/or to introduce new functionalities. Here we show that exchange of citrate molecules with α-trithiocarbonate-ω-carboxyl-terminated poly(N-isopropylacrylamide) can successfully stabilize spherical gold particles of different diameters ranging from 15 to 53 nm. This is verified by transmission electron microscopy, dynamic light scattering, and extinction spectroscopy. We show that the polymer-decorated nanoparticles respond to temperature and pH allowing access to control interparticle interactions. In a range of pH slightly below the pKa of the terminal carboxyl groups, phase transfer of the particles from water to chloroform can be mediated by increasing the dispersion temperature above the lower critical solution temperature of poly(N-isopropylacrylamide). Upon cooling, fully reversible phase transfer to the water phase is observed. Extinction spectroscopy reveals phase transfer efficiencies close to 100% for every system under investigation.