Magnetic Nano Sensor Particles with Luminescence Up-conversion Capability
Final Report Abstract
In conclusion, within this project a versatile strategy to synthesize monodisperse, pure hexagonal UCLNPs of small diameters (< 30 nm) was established. The synthesis could be upscaled to obtain one batch of approximately 2 g of such high quality particles. This is of great benefit due to the fact that the luminescence properties of UCLNPs vary from batch to batch. The characterization of the particles revealed a maximum quantum yield of about 1% in aqueous solution, which is one of the highest quantum yields for UCLNPs reported so far. A simple and cheap instrumentation for lifetime measurements of the upconversion luminescence has been realized. This setup allows in future the development of lifetime based sensor application. The advantage of such sensors in contrast to the luminescence intensity based sensors is their independency of the particle concentration, a parameter, which still is difficult to measure. Furthermore lifetime spectroscopy of UCLNPs will offer the possibilities to study the energy transfer to surface ligands in detail. It is expected that FRET systems could be optimized. The UCLNPs have been modified by different strategies in order to obtain colloidal stability in aqueous phase. A silica coating was applied for further functionalization with proteins. In a proof of concept approach BSA has been attached successfully to the particles. By using core/shell particles the luminescence intensity in aqueous solutions could be enhanced. Such UCLNPs have successfully been used as nanolamps for an enzymatically quantification of glucose and ethanol via inner filter effect based detection scheme.
Publications
- Magnetic Nanosensor Particles with Luminescence Upconversion Capability. Angewandte Chemie International Edition 2011, 50 (37), A59-A62
S. Wilhelm, T. Hirsch, E. Scheucher, T. Mayr, O. S. Wolfbeis
- Gd3+ dotierte lumineszierende Nanokristalle als Kontrastmittel in der MRT. RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren 2013, 185, VO309_5
C. Röhrer, M. Dollinger, S. Wilhelm, T. Hirsch, O. S. Wolfbeis, C. Fellner, C. Stroszczynski, P.Wiggermann
- Protein-reactive Multicolor Upconversion Nanoparticles. Theranostics 2013, 3, 239-248
S. Wilhelm, T. Hirsch, W.M. Patterson, E. Scheucher, T. Mayr, O. S. Wolfbeis
- Enzyme-induced Modulation of the Emission of Upconverting Nanoparticles: Towards a New Sensing Scheme for Glucose. Biosensors and Bioelectronics 2014, 59, 14-20
M. del Barrio, S. de Marcos, V. Cebolla, J. Heiland, S. Wilhelm, T. Hirsch, J. Galban
(See online at https://doi.org/10.1016/j.bios.2014.02.076) - Spectrally Matched Upconverting Luminescent Nanoparticles for Monitoring Enzymatic Reactions. ACS Appl. Mater. Interfaces, 2014, 6 (17), pp 15427–15433
S. Wilhelm, M. del Barrio, J. Heiland, S. F. Himmelstoss, J. Galban, O. S. Wolfbeis, T. Hirsch
(See online at https://doi.org/10.1021/am5038643)
