Niko Hildebrandt

Semiconductor quantum dots (QDs) have become important fluorescent probes for in vitro and in vivo bioimaging research. Their nanoparticle surfaces for versatile bioconjugation, their adaptable photophysical properties for multiplexed detection, and their superior stability for longer investigation times are the main advantages of QDs compared to other fluorescence imaging agents. Here, we review the recent literature dealing with the design and application of QD-bioconjugates for advanced in vi

Luminescent semiconductor quantum dots (QDs) are one of the more popular nanomaterials currently utilized within biological applications. However, what is not widely appreciated is their growing role as versatile energy transfer (ET) donors and acceptors within a similar biological context. The progress made on integrating QDs and ET in biological configurations and applications is reviewed in detail here. The goal is to provide the reader with (1) an appreciation for what QDs are capable of in

Colorful bioassays: Time- and color-resolved detection of Förster resonance energy transfer (FRET) from luminescent terbium complexes to different semiconductor quantum dots results in a fivefold multiplexed bioassay with sub-picomolar detection limits for all five bioanalytes (see picture). The detection of up to five biomarkers occurs with a sensitivity that is 40–-240-fold higher than one of the best-established single-analyte reference assays.

Nanobiotechnology is one of the fastest growing and broadest-ranged interdisciplinary subfields of the nanosciences. Countless hybrid bio-inorganic composites are currently being pursued for various uses, including sensors for medical and diagnostic applications, light- and energy-harvesting devices, along with multifunctional architectures for electronics and advanced drug-delivery. Although many disparate biological and nanoscale materials will ultimately be utilized as the functional building

The importance of microRNA (miRNA) dysregulation for the development and progression of diseases and the discovery of stable miRNAs in peripheral blood have made these short-sequence nucleic acids next-generation biomarkers. Here we present a fully homogeneous multiplexed miRNA FRET assay that combines careful biophotonic design with various RNA hybridization and ligation steps. The single-step, single-temperature, and amplification-free assay provides a unique combination of performance paramet

Semiconductor quantum dots possess unique photophysical properties such as bright emission with narrow wavelength bandwidth and extremely broad and strong absorption. In combination with their size-dependent color tunability, quantum dots have been proposed as ideal candidates for multiplexed optical bioanalysis for more than a decade. However, the unavailability of stable, reproducible, biocompatible quantum dots with controlled and functional multiple biolabeling has restricted these nanocryst

On the dot: Efficient energy transfer from Tb complexes to quantum dots with an extremely large Förster radius of 81 Å is achieved by formation of a streptavidin–biotin coupled donor–acceptor complex. The long luminescence lifetime of the Tb donor and the high absorption of the quantum dots make this couple a powerful tool for analyzing biological and biochemical interactions. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2005/z501

Semiconductor quantum dot nanocrystals (QDs) for optical biosensing applications often contain thick polyethylene glycol (PEG)-based coatings in order to retain the advantageous QD properties in biological media such as blood, serum or plasma. On the other hand, the application of QDs in Förster resonance energy transfer (FRET) immunoassays, one of the most sensitive and most common fluorescence-based techniques for non-competitive homogeneous biomarker diagnostics, is limited by such thick coat

The necessity to scrutinize more and more biological molecules and interactions both in solution and on the cellular level has led to an increasing demand for sensitive and specific multiplexed diagnostic analysis. Photoluminescence (PL) detection is ideally suited for multiplexed biosensing and bioimaging because it is rapid and sensitive and there is an almost unlimited choice of fluorophores that provide a large versatility of photophysical properties, including PL intensities, spectra, and l

Upconversion nanoparticles (UCNPs) are some of the most promising nanomaterials for bioanalytical and biomedical applications. One important challenge to be still solved is how UCNPs can be optimally implemented into Förster resonance energy transfer (FRET) biosensing and bioimaging for highly sensitive, wash-free, multiplexed, accurate, and precise quantitative analysis of biomolecules and biomolecular interactions. The many possible UCNP architectures composed of a core and multiple shells dop

Abstract Despite the significant advancements of developing upconversion nanoparticles (UCNPs) for high performance biosensing and bioimaging, the development of DNA‐functionalized UCNPs with thin coatings, efficient surface passivation, and fully functional DNAs for hybridization sensing in biological media remains extremely challenging. Here, a straightforward concept of labeling DNA to a thin polysulfonate polymer layer on UCNPs is presented. Both UCNPs and DNA preserve their full functionali

Fluorescence barcoding based on nanoparticles provides many advantages for multiparameter imaging. However, creating different concentration-independent codes without mixing various nanoparticles and by using single-wavelength excitation and emission for multiplexed cellular imaging is extremely challenging. Herein, we report the development of quantum dots (QDs) with two different SiO₂ shell thicknesses (6 and 12 nm) that are coated with two different lanthanide complexes (Tb and Eu)