Stable optical oxygen sensing materials based on click-coupling of fluorinated platinum(II) and palladium(II) porphyrins—A convenient way to eliminate dye migration and leaching

Abstract

Nucleophilic substitution of the labile para-fluorine atoms of 2,3,4,5,6-pentafluorophenyl groups enables a click-based covalent linkage of an oxygen indicator (platinum(II) or palladium(II) 5,10,15,20-meso-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin) to the sensor matrix. Copolymers of styrene and pentafluorostyrene are chosen as polymeric materials. Depending on the reaction conditions either soluble sensor materials or cross-linked microparticles are obtained. Additionally, we prepared Ormosil-based sensors with linked indicator, which showed very high sensitivity toward oxygen. The effect of covalent coupling on sensor characteristics, stability and photophysical properties is studied. It is demonstrated that leaching and migration of the dye are eliminated in the new materials but excellent photophysical properties of the indicators are preserved.

Advanced characterization of immobilized enzymes as heterogeneous biocatalysts

“…More hydrophilic carriers might require adaptation of the labeling procedure, using covalent fixation or other forms of deposition of the luminophore(s) on the surface, for example. However, manufacture of optical chemical sensors has been confronted with similar challenges, and there are already useful solutions to overcome them [187,211]. Hydrogels applied for encapsulation of enzymes and cells should be generally amenable to the fluorescence labeling [186].…”

Indicators for optical oxygen sensors

“…PtTFPP was also modified to be able to be polymerized and cross-linked with hydrophilic poly(2-hydroxyethyl methacrylate)-co-polyacrylamide or hydrophobic polystyrene to generate highly photostable and biocompatible sensing films [216]. Nucleophilic substitution of the parafluorine atoms of the pentafuorophenyl groups allows covalent coupling to polymeric materials such as polystyrene copolymers [114] and silica gel [25]. Due to its excellent photostability, PtTFPP has been extensively used for those applications in which high light intensities are used, primary in fiber-optic microsensors and microscopy [69], but also in multi-analyte sensors and as components for pressuresensitive paints [76].…”

Formation of a Fluorous/Organic Biphasic Supramolecular Octopus Assembly for Enhanced Porphyrin Phosphorescence in Air

“…The metalloporphyrin PtOEP and the free porphyrin base H 2 OEP (OEP = 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine) were selected because of their wide-ranging applications. [10][11][12] DFT calculations showed that the molecular electrostatic potentials (MEPs) of H 2 OEP and PtOEP exhibit an electronrich (p-basic) region at the center of the squares whereas [Ag 3 (m 1,2 -3,5-(n-C 3 F 7 ) 2 Tz) 3 ] (1) is very electron-poor (strongly p-acidic) at the center of the nine-membered ring (Scheme 1 b Figure 1) with one benzene molecule per asymmetric unit. The adduct pair consists of fluorous bowl-shaped 1 and H 2 OEP, which are held together by coordination, p-stacking (quadrupole-quadrupole), and van der Waals forces.…”