Novel Fluorescent Methods for Biotechnological and Biomedical Sensoring: Assessing Antioxidants, Reactive Radicals, NO Dynamics, Immunoassay, and Biomembranes Fluidity

Abstract

We proposed and developed a series of fluorescent methods for analysis and investigation of biological systems with a view of future biotechnological and biomedical applications. The methods we describe have been built upon several photochemical and photophysical phenomena including fluorescent quenching, photochrome photoisomerization, and energy transfer. Three new types of molecular probes have been developed and employed for such studies: (1) dual fluorophore-nitroxide compounds, (2) fluorescence-photochrome molecules, and (3) super molecules containing both fluorescence and fluorescent quenching segments. The fluorescent properties of the new probes were intensively exploited for several practical applications including a real-time analysis of antioxidants, nitric oxide, superoxide, reactive radicals, trinitrotoluene, and metal ions, investigation of molecular dynamics of biomembranes in a wide range characteristic times, detection of protein conformational transition, and characterization of surface system. Owning high sensitivity, simplicity, and availability of fluorescent techniques, these methods can be widely employed and are adaptable to fibrooptic sensoring. A general survey of the physical principles and application of the new fluorescent methods has been provided.

Stilbenes Synthesis and Applications

“…The following version of this approach have been developed: probing based on solvatochromism, (184), image and structure probing (185), using accessibility of reactive groups probes binding to proteins, (186), fluorescence-photochrome method (187,188), and cascade spin-triplet-photochrome systems (189) for study of the molecular dynamics of proteins and biomembranes, sensoring for surface microviscosity and ascorbic acid in systems immobilized on quartz slides (55), chracterization of solid-phase antibody orientation (101), fluorescence-photochrome immunoassay (102), nitric oxide analysis using suppermolecules containing stilbene and fluorescent quenching heme group (190), probing for hydrid compounds (191).…”

Detection and Imaging of Superoxide in Roots by an Electron Spin Resonance Spin-Probe Method

“…In addition, ESR studies on hydroxyl radicals in cucumber roots and Arabidopsis seedlings yielded a general localization of this ROS species (21). A combined ESR/fluorescence probe was also used for in vitro applications (22).…”

Interplay between Solution Processing and Electronic Structure in Metal-Free Organic Magnets Based on a TEMPO Pentacene Derivative

“…The choice of the substituent attached to the radical plays an important role, not only from a chemical stability point of view but also for the processes of growth and for potential applications. The vapor pressure of the molecules impacts their film stability: molecules with higher vapor pressure at room temperature (RT) are volatile, − making it difficult to reach the necessary thermodynamic equilibrium for a stable film at device working temperatures. − We have clearly demonstrated this effect in thin films of open-shell systems by comparing the thin-film stability of the mentioned pyrene derivatives characterized by different vapor pressures. , In addition, it is well-known that a free radical coupled to a fluorophore suppresses the normal fluorescence emission process. , In such a molecule, the radicals, e.g., nitroxides, are efficient quenchers of the fluorescence, due to the relaxation of the fluorophore excited states caused by electron-exchange interactions with the radical. − …”