Florida State University Research Foundation, Inc.

Goutam Palui

Hedi M Mattoussi

Hyon Bin Na

Wentao Wang

Igor Alabugin

Naiqian Zhan

Tommaso Avellini

A series of multicoordinating and multifunctional ligands optimized for the surface-functionalization of luminescent quantum dots (QDs) and gold nanoparticles (AuNPs) alike is disclosed. An L-aspartic acid precursor is modified with functionality, through simple peptide coupling chemistry, one or two lipoic acid (LA) groups and poly(ethylene glycol) (PEG) moieties in the same ligand. These ligands were combined with a new photoligation strategy to yield hydrophilic and reactive QDs that are colloidally stable over a broad range of conditions, including storage at nanomolar concentration and under ambient conditions.

Controlling the architecture, coordination, and reactivity of nanoparticle coating utilizing an amino acid central scaffold

The disclosure is directed to multi-coordinating polymers as ligands that combine two distinct metal-chelating groups, lipoic acid and imidazole, for the surface functionalization of QDs. These ligands combine the benefits of thiol and imidazole coordination to reduce issues of thiol oxidation and weak binding affinity of imidazole. The ligand design relies on the introduction of controllable numbers of lipoic acid and histamine anchors, along with hydrophilic moieties and reactive functionalities, onto a poly(isobutylene-alt-maleic anhydride) chain via a one-step nucleophilic addition reaction. We further demonstrate that this design is fully compatible with a novel and mild photoligation strategy to promote the in-situ ligand exchange and phase transfer of hydrophobic QDs to aqueous media under borohydride-free conditions. Ligation with these polymers provides highly fluorescent QDs that exhibit great long-term colloidal stability over a wide range of conditions.

Photoligation of an amphiphilic polymer with mixed coordination provides compact and reactive quantum dots

A method for the photo-mediated phase transfer of inorganic nanocrystals, such as luminescent quantum dots, QDs, is provided. Irradiation, specifically UV excitation (&#x3bb;&#x3c;400 nm), promotes the in-situ ligand exchange of hydrophobic quantum dots with hydrophilic ligands and their facile transfer to polar solvents and buffer media. The technique enables transfer of quantum dots and other nanocrystal materials from hydrophobic to polar and hydrophilic solutions.

Photo-induced phase transfer of luminescent quantum dots

The disclosure is directed to polymer ligands that are optimally suited for surface-functionalizing magnetic nanoparticles. The amphiphilic polymers are prepared by coupling several amine-terminated anchoring groups, polyethylene glycol moieties, and reactive groups onto a poly(isobutylene-alt-maleic anhydride) (PIMA) chain. The reaction of maleic anhydride groups with amine-containing molecules is highly-efficient and occurs in one-step. The availability of several dopamine groups in the same ligand greatly enhances the ligand affinity, via multiple-coordination, to the magnetic NPs, while the hydrophilic and reactive groups promote colloidal stability in buffer media and allow subsequent conjugation with target biomolecules. Nanoparticles ligated with terminally reactive polymers have been easily coupled to target dyes and tested in live cell imaging with no measurable cytotoxicity.

Polymer ligands for nanoparticles

In a composition aspect of the invention, a nanoparticle coating comprises repeating polyacrylic acid monomers covalently bound together in an aliphatic chain having a plurality of carboxylic acid functional groups and modified carboxylic acid functional groups extending therefrom. A first portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal methoxy functional group and a second portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having at least one terminal sulfur moiety.

Polyethylene glycol based oligomers for coating nanoparticles, nanoparticles coated therewith, and related methods

In a composition aspect of the invention, a nanoparticle coating comprises repeating polyacrylic acid monomers covalently bound together in an aliphatic chain having a plurality of carboxylic acid functional groups and modified carboxylic acid functional groups extending therefrom. A first portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal methoxy functional group and a second portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having at least one terminal catechol group.

In a composition aspect of the invention, a nanoparticle coating comprises repeating polyacrylic acid monomers covalently bound together to form an aliphatic chain having a plurality of carboxylic acid functional groups and modified carboxylic acid functional groups extending therefrom. A first portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal methoxy functional group and a second portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having at least one terminal sulfur moiety.

Growing community of inventors

Tallahassee, FL, United States of America

Goutam Palui