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The surface modification of fabrics composed of Kevlar®, Nomex®, or VAR was extensively investigated. Kevlar® and Nomex® are widely-utilized aramid materials, whereas VAR is a technical fabric comprising 64% viscose, 24% para-aramid (Kevlar®), 10% polyamide, and 2% antistatic fibers. Both aramid materials and cellulose/viscose exhibit exceptional mechanical properties that render them valuable in a wide range of applications. For the herein studied modification of Kevlar®, Nomex®, and VAR, we used small organic molecules 3-allyl-5,5-dimethylhydantoin (ADMH) and 3-(acrylamidopropyl)trimethylammonium chloride (APTAC), which were anchored onto the materials under study via graft polymerization. By doing so, excellent antibacterial properties were induced in the three studied fabrics. Their water repellency was improved in most cases as well. Extensive characterization studies were conducted to probe the properties of the modified materials, employing Raman and FTIR spectroscopies, Scanning Electron Microscopy (SEM), and thermogravimetric analysis (TGA).

Mitochondria-targeting drugs and diagnostics are used in the monitoring and treatment of mitochondrial pathologies. In this respect, a great number of functional compounds have been made mitotropic by covalently attaching the active moiety onto a triphenylphosphonium (TPP) cation. Among these compounds, a number of molecular detectors for reactive oxygen species (ROS) are based on fluorescent and chemiluminescent probes. In this regard, luminol (probably the most widely known chemiluminescent molecule) has been employed for a number of biological applications, including ROS detection. Its oxidation under specific conditions triggers a cascade of reactions, ultimately leading to the excited 3-aminophthalate (3AP *), which emits light upon deactivation. Hence, the photophysical interaction between the light-emitting species 3AP * and TPP cations needs to be evaluated, as it can add valuable information on the design of novel emission-based mitotropic systems. We herein investigate the quenching effect of ethyltriphenylphosphonium cation onto substituted 3-aminophthalates. These were prepared in situ upon hydrolysis of the corresponding anhydrides, which were synthesized from 3-aminophthalimides. Steady-state fluorescence and time-resolved experiments were employed for the evaluation of a possible electron transfer quenching by phosphonium ions. Our experimental results confirmed such quenching, suggesting it is mainly dynamic in nature. A minor contribution of static quenching that was also detected is attributed to complex formation in the ground state. Accordingly, the chemiluminescence of luminol was indeed strongly reduced in the presence of phosphonium ions. Our results have to be taken into account during the design of new chemiluminescent mitotropic drugs or diagnostic agents of the luminol family.

Fluorescein, and derivatives of fluorescein, are often used as fluorescent probes and sensors. In systems where pH is a variable, protonation/deprotonation of the molecule can influence the pertinent photophysics. Fluorination of the xanthene moiety can alter the molecule’s pKa such as to render a probe whose photophysics remains invariant over a wide pH range. Di-fluorination is often sufficient to accomplish this goal, as has been demonstrated with compounds such as Oregon Green in which the xanthene moiety is symmetrically difluorinated. In this work, we synthesized a non-symmetrical difluorinated analog of Oregon Green which we call Athens Green. We ascertained that the photophysics and photochemistry of Athens Green, including the oxygen-dependent photophysics that results in the sensitized production of singlet oxygen, O2(a1Δg), can differ appreciably from the photophysics of Oregon Green. Our data indicate that Athens Green will be a more benign fluorescent probe in systems that involve the production and removal of O2(a1Δg). These results expand the available options in the toolbox of fluorescein-based fluorophores.

The monitoring of reactive oxygen species in living cells provides valuable information on cell function and performance. Lately, the development of chemiluminescence-based reactive oxygen species monitoring has gained increased attention due to the advantages posed by chemiluminescence, including its rapid measurement and high sensitivity. In this respect, specific organelle-targeting trackers with strong chemiluminescence performance are of high importance. We herein report the synthesis and chemiluminescence properties of eight novel phosphonium-functionalized amino-acylated luminol and isoluminol derivatives, designed as mitochondriotropic chemiluminescence reactive oxygen species trackers. Three different phosphonium cationic moieties were employed (phenyl, p-tolyl, and cyclohexyl), as well as two alkanoyl chains (hexanoyl and undecanoyl) as bridges/linkers. Synthesis is accomplished via the acylation of the corresponding phthalimides, as phthalhydrazide precursors, followed by hydrazinolysis. This method was chosen because the direct acylation of (iso)luminol was discouraging. The new derivatives’ chemiluminescence was evaluated and compared with that of the parent molecules. A relatively poor chemiluminescence performance was observed for all derivatives, with the isoluminol-based ones being the poorest. This result is mainly attributed to the low yield of the fluorescence species formation during the chemiluminescence oxidation reaction.