Fluorophore luminescent label

The use of europium chelates, with their unusually long fluorescence decay times, as labels for proteins and antibodies has provided techniques that are referred to as time-resolved fluoroimmunoassays (TRFIA). Fluorophores as labels for biomolecules will be the topic of Sect. 3. Nevertheless, TRFIAs always have to compete with ELISA (enzyme-linked immunosorbent assays) techniques, which are characterized by their great versatility and sensitivity through an enzyme-driven signal amplification. Numerous studies have been published over the past two decades which compare both analytical methods, e.g., with respect to the detection of influenza viruses or HIV-1 specific IgA antibodies [117,118]. Lanthanide luminescence detection is another new development, and Tb(III) complexes have been applied, for instance, as indicators for peroxidase-catalyzed dimerization products in ELISAs [119]. 

An attractive alternative to organic fluorophores in formulated polymeric sensor films for chemical detection is to use inorganic luminescent materials. Semiconductor nanocrystals have a dramatically improved photostability and are attractive as luminescent labels.1415 However, some nanocrystals also exhibit photoluminescence (PL) that is sensitive to the local environment. For example, it was observed that PL of CdSe nanocrystals incorporated into polymer thin films responded reversibly to different gases.16 Because in sensing applications nanomaterials bring previously unavailable capabilities1719 and unexpected results,20 23 we explored the environmental sensitivity of semiconductor nanocrystals upon their incorporation in different rationally selected polymeric matrices.24 26... 

Nucleic acid microarrays are generally limited by low hybridizatiOTi efficiency and the moderate sensitivity provided by conventimial luminescent labels. Van de Rijke et al. [28] designed an experimental setup for the direct comparisOTi of UPT and the conventional fluorophore Cy5 (Fig. 4a). Microarrays were hybridized with... 

The intense Texas Red fluorophore has a QY that is inherently higher than the tetrameth-ylrhodamine or Lissamine rhodamine B derivatives. Texas Red s luminescence is shifted maximally into the red region of the spectrum, and its emission peak only minimally overlaps with that of fluorescein. This makes Texas Red derivatives among the best choices of labels for use in double-staining techniques. 

Oligonucleotide probes may be labeled with small fluorescent molecules for detection of hybridization by luminescence. Fluorescent probes are widely used in assay systems involving bio-specific interactions (Chapter 9). Receptors for ligands may be localized in tissues or cells by modification of the ligand with the appropriate fluorophore. Targeted molecules may be... 

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