Kluenker, Martin

PhD student

Phone: +49 6131/39-24417
E-Mail: martin.kluenker@uni-mainz.de

Synthesis and Characterization of Multifunctional Nanoparticles and their Application

The application of nanotechnology in medical practice offers a number of advantages over conventional diagnostics and therapeutics. Properly developed, high surface area nanoparticles and other nanoscale therapeutics show improved intracellular penetration, enhanced absorption into selected tissues, better pharmacokinetic properties, increased clinical efficacy and reduced toxicity. Furthermore, the unique reactivities and sizes of these functional nanomaterials make them ideally suited for the design of multifunctional systems incorporating different diagnostic and therapeutic capabilities (“theranostic”) into a single nanosized vehicle.
Recently, nanocomposites containing two or more different nanoscale functionalities (multifunctional nanoparticles) have attracted the attention of nanotechnologists and scienctists because these materials illustrate physical and chemical properties such as enhanced optical, magnetic and catalytic properties that differ considerably from individual single-component materials. The nonsymmetric structure may facilitate introduction of an anisotropic distribution of different surface functional groups. Specific shapes like as nanocorns, dumbells, nanorods, multipods, cubic and core shell have been reported with several methods for the preparation of multifunctional nanoparticles.

My focus of research is to design novel and facile protocols for the synthesis of size and shape-controlled metal (M where M=Pd, Au) and M@Fe2O3 multifunctional nanoparticles. The multifunctional nanoparticles are prepared by a seed mediated growth process. The shape and even size of the different domains could be affected by solvent’s type due to polarity, electron transfer and crystallinity of the metal. Due to the synergistic properties induced by the intimate contact and the interaction between different components, hybrid nanostructures can achieve enhanced properties and provide novel functions not available in the single phase nanostructures.

In order to exploit their immediate use in biomedical applications, the as synthesized multifunctional nanoparticles require replacement of the capping agent by highly hydrophilic and biocompatible ligands. This can be achieved through surface functionalization using PEG based polymer or silica coating. The hydrophilic functionalization also enables the possibility of biomolecule conjugation e.g. antibodies, drugs etc.
The shape-controlled Pd particles are interesting for catalytic applications such as enzyme mimic reactions e.g. dehydrogenases or superoxide dismutases (SOD) whereas superparamagnetic iron oxide domains can be used as magnetically triggered separation of catalyst or as magnetic resonance imaging (MRI) contrast agent.

The characterization includes mainly Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), UV/VIS Spectroscopy, Atomic Absorption Spectroscopy (AAS), X-Ray-Diffraction (XRD), Infrared Spectroscopy (IR), as well as NMR/MRI Measurements.