Applications molecular probes

The increasing interest of researchers for fluorescent probes can be explained by the great improvement of the sensitivity and the spatial or temporal resolution of instruments, and by the development of a wide choice of commercially available probes for particular applications (Molecular Probes, Inc., United States Lambda Fluoreszenztechnologie Ges.m.b.H., Austria). However, there is still a need for probes with improved specific response and minimum perturbation of the microenvironment, in particular in the field of ion recognition which is the object of this chapter. 

Finally, do dendrimers change greatly in size when placed in different solvents For applications as size standards or molecular probes dendrimers possessing a relatively fixed size would be preferable. For applications using the release of stored guest molecules, however, it would be preferable to open and close dendrimers by designing appropriate container release strategies . 

The squaraine rotaxanes based on the macrocycle 16b exhibit intense NIR absorption and emission maxima, and it should be possible to develop them into molecular probes for many types of photonic and bioimaging applications. In contrast, the squaraine fluorescence intensity is greatly diminished when the dye is encapsulated with macrocycle 18. The fluorescence is restored when a suitable anionic guest is used to displace the squaraine dye from a pseudorotaxane complex, which indicates that the multicomponent system might be applicable as a fluorescent anion sensor. 

Abstract Conjugated polymers have many unique photophysical properties that make them useful for a variety of applications within the fields of chemistry, molecular biology, and medicine, specifically their ability to produce a conformation-dependant spectral signature reflective of changes in their local environment. This physical property makes conjugated polymers an indispensible tool in the toolbox of fluorescent reporters, and within this chapter, their utilization as molecular probes for studying protein structure and conformation is emphasized. 

It is worth recalling that other types of probes are used in practice for example, radioactive tracers, with their well-known drawback of their radioactivity, and EPR (electronic paramagnetic resonance) probes that provide information mainly on molecular mobility. In contrast to these probes, which are used in rather limited fields of applications, fluorescent probes can offer a wealth of information in various fields, as shown in Table 1.4. The various examples described in this book will demonstrate their outstanding versatility. 

The mechanisms of resonance energy transfer (RET) between a donor and an acceptor have been described in Section 4.6.3. The aim of this chapter is to present further aspects of RET and its applications for probing matter or living systems. RET is particularly widely used to determine distances in biomolecules and supra-molecular associations and assemblies. 

Molecular probe dyes for the determination of potassium, lithium, and sodium have been identified. Additionally, an NIR probe selective for potassium has been fabricated. The detection limits of this probe are in the ppm range. Lower detection limits may be achieved by varying the matrix which allows the entrapment of ions. Preliminary data for the detection of lead and cadmium demonstrate the potential capability of these probes for environmental applications. The development of OFMP for the detection of other ions of environmental interest such as Be2+, Hg2+, As3+, and Ni2+ is currently underway. 

The Handbook of Fluorescent Probes and Research Chemicals by R. P. Haugland is a useful resource for over 1800 fluorescent probes and their applications. It is published yearly by Molecular Probes, 4849 Pitchford Ave., Eugene, OR 97402. See also http //www.probes.com. 

The tunability in size and properties of the materials described in the previous sections is so large that we expect them to find applications in different fields such as optoelectronics, pigments, molecular probes, and educational tools. We focus on five applications among these. Some of them are already feasible, whereas others require further development. 

H.P. Shukla, Application of Perfluorocarbon Emulsions as Fluorine-19 Nuclear Magnetic Resonance Molecular Probes of Cardiac Tissue Oxygen Tension, University of Texas Southwestern Graduate School of Biomedical Sciences, 1994Ph.D.. 

Our motivation for offering a further consideration of excimer fluorescence is that it is a significant feature of the luminescence behavior of virtually all aryl vinyl polymers. Although early research was almost entirely devoted to understanding the intrinsic properties of the excimer complex, more recent efforts have been directed at application of the phenomenon to solution of problems in polymer physics and chemistry. Thus, it seems an appropriate time to evaluate existing information about the photophysical processes and structural considerations which may influence excimer formation and stability. This should help clarify both the power and limitations of the excimer as a molecular probe of polymer structure and dynamics. 

Bengali women to symbolize marriage. Only Bengali women wear the red spot at the center of the forehead. The decorative spot worn in the middle of the forehead by other Indian women is—today—pasted on. Much of the history of Rose Bengal has been reviewed elsewhere [241], Citations to Rose Bengal have increased in the last three or so years, and the diversity of its application has greatly expanded. Many of the Rose Bengal derivatives listed are now commercially available from either Molecular Probes or Aldrich. 

This account has summarized several of our approaches to the preparation of electric-field-aligned chromophoric polymers for second order NLO applications. Molecular design has been employed wherever possible to arrive at structures that probe particular aspects of the polar orientation issue. The rich variety of accessible organic structures has enabled us to consider the orientation problem from a variety of points of view, and to indicate by example the manner in which multifunctional organic synthesis may play a role in the fabrication of oriented materials. 

Fluorescence of Excited Singlet-State Acids in Certain Organized Media Applications as Molecular Probes... 

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