Water-Soluble Chitosan-Europium Hybrid Sensor for Singlet Oxygen Detection.

The ability to effectively monitor singlet oxygen (O) with fluorescence probes in biological systems is severely restricted mainly by the background autofluorescence of these systems. Though the application of lanthanide complexes as O monitors successfully resolves this problem with time-gated luminescence measurements, the insolubility of these complexes in an aqueous medium heavily limits their application in biological systems. Here, we present a water-soluble O sensor based on a chitosan-europium hybrid material.

High brightness red emitting polymer beads for immunoassays: Comparison between trifluoroacetylacetonates of Europium.

Efficiently luminescing spherical polymer particles (beads) in the nanoscale regime of up to approximately 250 nm have become very valuable tools in bioanalytical assays. Eu- complexes imbedded in polymethacrylate and polystyrene in particular proved to be extraordinarily useful in sensitive immunochemical and multi-analyte assays, and histo- and cytochemistry. Their obvious advantages derive from both, the possibility to realize very high ratios of emitter complexes to target molecules, and the intrinsically long decay times of the Eu-complexes, which allows an almost complete discrimination against bothersome autofluorescence via time-gated measuring techniques; the narrow line emission in conjunction with large apparent Stokes shifts are additional benefits with regard to spectral separation of excitation and emission with optical filters.

Design and Mechanism of Rare-Earth Singlet Oxygen Sensing: An Experimental and Quantum Chemical Approach.

The sensitive detection of singlet oxygen (O) is one key issue in various photochemical analyses, reactions, and processes; it is indispensable for designing catalysts for photodynamic therapies. Corresponding fluorescence-based organic O monitor luminophores may be equipped with rare-earth complexes with several intrinsic advantages. The design of the necessary ligands being a tedious, time-consuming effort, often involving empirical guesswork, we decided to support our experimental work with quantum chemical calculations.