Hybrid Nanoprobes Of Peptide-Functionalized Quantum Dots And Magnetic Nanocrystals, Interfaced Via Amphiphilic Multifunctional Polymer Ligands

Florida State University, Tallahassee FL

Investigators

Abstract

With this award, the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division is funding Drs. Hedi Mattoussi and Debra Fadool at the Florida State University to develop strategies to modify the surfaces of inorganic nanomaterials so that they can bind with biological systems. This will yield systems that can be used to probe specific biological species and monitor targeted biological processes without affecting the integrity of the host system. To meet this goal, new multifunctional polymers that strongly coordinate onto various nanomaterials will be designed, providing water-compatible nanoprobes that are easy to introduce into biological media/systems. The work at Florida State University provides a good example where nanotechnology is used to address important problems in biology. The present project is interdisciplinary in nature and it provides opportunities for training graduate and undergraduate students in areas such as growth and functionalization of nanocrystals, peptide design and synthesis, protein expression, and several other analytical techniques. Prof. Mattoussi and co-workers will also carry out outreach activities to undergraduate students, including students from underrepresented groups. The project focuses on developing amphiphilic polymers as surface ligands that can tightly coordinate onto the surfaces of inorganic nanomaterials, including magnetic nanoparticles, luminescent quantum dots and gold nanoparticles. The chemical design exploits the effectiveness of the nucleophilic addition reaction to allow the simultaneous insertion of hydrophilic moieties, metal-coordinating groups and reactive functions on the same polymer platform. By combining multi-anchoring groups with hydrophilic and biologically-reactive functionalities in the same amphiphilic polymer, our design will enhance the ligand-to-nanoparticle binding, while facilitating their coupling to various target molecules. This approach will allow conjugation of QDs and magnetic nanocrystals to several target molecules, including dopamine and the margatoxin (MgTx) peptide. These resulting conjugates will be used to develop specific biosensors. In particular QD-dopamine conjugates will provide platforms that can target iron ions and cysteine-rich proteins in vitro and in cell cultures. Similarly, nanoparticle-MgTx conjugates will be used to control the current flow through the Kv1.3 potassium channels of mitral cells.