Fluorescent particles

The Q-materials of CdjPj and CdjAsj mentioned in the preceding section fluoresce strongly both in solution and in the solid state. The fluorescence band, which often shows a structure, has its maximum at a wavelength substantially longer than that of the onset of absorption. 10 nm particles fluoresce mainly in the infrared, 2nm particles fluoresce green. All kinds of fluorescence color were observed for particles within this size range 62,63.240)... 

Ebenstein Y, Mokari T, Banin U (2002) Fluorescence quantum yield of CdSe/ZnS nanocrystals investigated by correlated atomic-force and single-particle fluorescence microscopy. Appl Phys Lett 80 4033 1035... 

Koch U, Fojtik A, Weller H, Henglein A (1985) Photochemistry of semiconductor colloids preparation of extremely small ZnO particles, fluorescence phenomena and size quantization effects. Chem Phys Lett 122 507-510... 

If the nanodispersed species have sizes of the order of 10 nm, diagnostic agents encapsulated in such nanoparticles could potentially cross into human cells. For example, 10 nm diameter, silica-coated, cadmium selenide crystals have been able to transfer into vesicles and be transported by them [901], These protein-sized particles fluoresce for long periods of time making them potentially useful for diagnostic labelling. 

Figure 4.10 Summary of 457 individual particle fluorescence vs. LSPR peak position measurements with three different fluorescent dyes. The LSPR peak positions are binned in 20 nm intervals along the x-axis. The average fluorescence intensity observed from particles within each bin is then plotted as a function of the LSPR position for Ag nanoprisms functionalized with (A) Alexa Fluor 488, (B) Alexa Fluor 532 and (C) Rhodamine Red dyes. The absorption spectra (dotted lines) and emission spectra (dashed lines) are plotted for reference for each dye. The solid...

Hong, B. and Kang, K. A. (2006). Biocompatible, nanogold-particle fluorescence enhancer for fiuorophore mediated, optical immunosensor. Biosens. Bioelectron. 21 1333-1338. 

Spectroscopic analysis may involve irradiation (illumination) with photons (light), particles of matter (such as electrons) or phonons (vibrational modes). The material under analysis may transmit, reflect or absorb these particles. In the case of absorption, re-emission of the same particle or a different particle or number of particles may take place. Also, in the case of photons, for example, the wavelength of the emitted particle may be different than the absorbed particle. Fluorescence spectroscopy is a particular example that involves the investigation of samples for which the emitted of particles have a different wavelength than that of the incident particles. 

Functional group labeling and detection with fluorescent latex particles Fluorescent dye loaded micro- and nanoparticles. Diagnostic assay use (particularly in immunochromatography tests) and flow cytometry. 33... 

Particle morphology can be studied by fluorescence quenching if individual components of the particles can be labelled by covalent attachment of an appropriate dye [84]. The use of a fluorescence quencher to decrease the particle fluorescence intensity served to probe the interphase zone formation or the sharpness of the interface between polymer phases in the particles. 

Interactions between the HIV-1 regulatory protein. Rev, and the Rev responsive element (RRE) RNA, as well as the effect of inhibitors on these interactions, were monitored using a single-particle fluorescence-based method [203]. This biosensing method combined FRET and the colocalization of fluorophores as the means of detection. In the presence of an analyte, the dye-labeled recognition complex was assembled on the fluorescent QDs, and these were tunneled, under flow, into two detector channels that simultaneously analyzed the fluorescence of the QDs and the FRET emission of the dye. The two emissions were observed simultaneously only if... 

D illuminated section, the dyed particles fluoresce and an image is taken perpendicular to the laser sheet, giving a clear slice of the 3D structure. This image is used directly to follow particles that are currently in the slice or the laser is then scanned to produce sufficient slices to reconstruct a full 3D image of the sample. 

Flow Cytometry [26,27,28] Single particle fluorescence and scattering Cell analysis Flow... 

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