Sensors biosensors, luminescent

Papkovsky D.B., Ovchinnikov A.N., Ogurtsov V.I., Korpela T., Biosensors on the basis of luminescent oxygen sensor the use of microporous light-scattering support materials. Sens. Actuat.B 1998 51 137-145. 

Orellana G, Garcia-Fresnadillo D (2004) Environmental and industrial optosens-ing with tailored luminescent Ru(II) polypyridyl complexes. In Narayanaswamy R, Wolfbeis OS (eds) Optical sensors industrial, enviromental and diagnostic applications. Springer series on chemical sensors and biosensors vol 1. Springer, Berlin Heidelberg New York, p 309-357... 

All of the aforementioned biosensors are designed for a standard stirred-tank bioreactor they will not work with smaller-scale vessels such as shake flasks. Small noninvasive sensors have been developed to measure D.O. and pC02 inside shake and T-flasks40,41 A D.O. or pC02 detecting patch is placed in the flask, and this patch contains an oxygen or carbon dioxide luminescent dye. The color shifts of these dyes are detected using an external fluorometer. 

Optical biosensors can be defined as sensor devices which make use of optical principles for the transduction of a biochemical interaction into a suitable output signal. The biomolecular interaction on the sensor surface modulates the light characteristics of the transducer (i.e., intensity, phase, polarization, etc.), and the biosensing event can be detected by the change in diverse optical properties such as absorption, fiuorescence, luminescence or refractive index, among others. 

In optical sensors and biosensors, detection is based on measurements of change of any optical characteristics of medium that is caused by the presence of analyte (mostly optical absorption, reflection, or luminescence). Although first optic sensors... 

Transgenic bacterial biosensors. Systems such as the Microtox assay detailed earlier use the marine species Vibrio fischeri as the sensor. Because it uses a marine bacterium, Microtox must be conducted in saline solution, which is ecologically irrelevant for most soils. Because no naturally luminescent soil bacteria are known that could be used as an alternative, one solution is to fuse the genes responsible for bioluminescence into soil-dwelling strains using recombinant technology (Paton et al., 1997). Two approaches can be used ... 

Tencaliec A. M., Laschi S., Magearu V., and Mascini M., A comparison study between a disposable electrochemical DNA biosensor and a Vibrio fischeri based luminescent sensor for the detection of toxicants in water samples, Talanta, 69, 365-369, 2006. 

Biosensors, p. 115 DNA Nanotechnology, p. 475 Fluorescence Sensing of Anions, p. 566 Fluorescent Sensors, p. 572 Imaging and Targeting, p. 687 Luminescent Materials, p. 875 Photochemical Sensors, p. 1053 Supramolecular Photnchernistn, p. 1434... 

The interplay between nanopartides and biological systems is of spedal relevance for semiconductor nanopartides, known simply also as quantum dots (QDs). In recent years, these have emerged as ideal systems for molecular sensors and biosensors, based largely on their sizewide variety of chemical functionalities with which QDs can be equipped that makes them ideal partners for different biosystems. In contrast to former passive optical labds, specifically functionalized QDs can operate as optical labds so as to observe the dynamics of biocatalytic transformations and conformational transitions of proteins. This development will surely open a wide variety of doors in modem nanobiotechnology. 

Current gold nanopaiticle solution based methods of biosensing are not limited strictly to this one type of nanopaiticle but can incorporate other particles as well. Peptide linked gold nanoparticle - quantum dot biosensors have been created by Chang et al., that rely on the ability of the gold nanoparticles to quench the photoluminescence of the quantum dots when in their close proximity bound state [26]. The method of sensing is also considered an on sensor since the default state of the particles is off (no luminescence), and it is converted to on (luminescence) once sensing takes place. 

Lo and coworkers also reported an interesting application of a complex of this family, this time as sensor for Zn " and Cd ions [68]. To do so, they prepared 21, a rhenium tricarbonyl complex, and 22 (Scheme 11.5), the same molecule coupled with a tyramine-derived 2,2 -dipicolylamine (DPAT) imit known as a chelator of Zn " and Cd " ions. In vitro studies showed that 21 was luminescent, while 22 was not This is due to the quenching of fluorescence induced by the DPAT ligand. However, limiinescence was recovered after addition in the medium of Zn " " or Cd " ions. FeasibiUty of using 22 as biosensor for these two cations has been demonstrated on HeLa cells incubated in the presence of 22... 

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