Herein we report the highly efficient and sensitive detection of hydrogen peroxide in both aqueous solution and in the vapor phase via fluorescence quenching (turn-off mechanism) of the amplified fluorescent conjugated polymer-titanium complex induced by hydrogen peroxide. Inter- and intra-polymer energy migration leads to extremely high sensitivity.

Reported herein is the use of chiral cationic polyamines for two intriguing applications: fabrication of chiral covalently-linked microcapsules, and enantiospecific delivery of siRNA to Huh 7 cells. The microcapsules are easily fabricated from homochiral polymers, and the resulting architectures can be used for supramolecular chiral catalysis and many other potential applications. Enantiospecific delivery of siRNA to Huh 7 cells is seen by one 'enantiomer' of the polymers delivering siRNA with significantly improved transfection efficiency and reduced toxicity compared to the 'enantiomeric' polymer and commercially available transfection reagents. Taken together, the use of these easily accessible polyamine structures for diverse applications is highlighted in this Letter herein and can lead to numerous future research efforts.

Reported herein is the highly efficient quenching of fluorescent organic nanoparticles by 2,4-dinitrotoluene and 2,4,6-trinitrotoluene. These fluorescent nanoparticles are formed from the hydrophobic collapse of fluorescent polymer chains and display quenching efficiencies that are in line with the highest reported literature values. Moreover, the fluorescent quenching occurs only for the fluorescent nanoparticles, and not for the precursor polymer solutions, which display marked insensitivity to the presence of nitroaromatics. This aggregation-dependent fluorescent quenching has numerous applications for the detection of small-molecule electron-deficient analytes. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4150–4155

Organic fluorophores are rarely synthesized at the undergraduate level, often because of the tedious procedures required for their synthesis. One example of such fluorophores, squaraines, are a class of near-infrared emitting fluorophores with unique photophysical properties. Squaraines are often synthesized via the condensation of an electron-rich aniline with squaric acid, refluxed overnight in a mixed solvent system. Reported herein are the syntheses of a variety of organic fluorophores in an undergraduate laboratory setting, including modifications to the literature-reported synthesis of a particular squaraine molecule that allowed it to be synthesized at the undergraduate level. The photophysical properties of these fluorophores can also be analyzed. Finally, the fluorophores can be used for a variety of interesting applications, including the fabrication of hybrid thin films and nanoparticles with fluorescent conjugated polymers.

Reported herein is a new method for the detection of polycyclic aromatic hydrocarbons (PAHs) which relies on energy transfer from the PAH to a near-infrared emitting squaraine fluorophore. This energy transfer occurs inside the gamma-cyclodextrin cavity, with up to 35% emission observed from energy transfer compared with exciting the squaraine directly.

Squaraines are a class of organic fluorophores that possess unique photophysical properties, including strong near-infrared absorption and emission. The synthesis of many squaraines involves the condensation of an electron-rich aromatic ring with squaric acid. These reactions are generally refluxed overnight in a benzene-butanol solvent mixture. Reported herein are modifications to the synthesis of a squaraine dye that allowed the experiment to be performed in an undergraduate laboratory setting. The desired compound was formed after a 2-h reflux, using toluene as a co-solvent rather than the more toxic benzene. Moreover, the photophysical properties of the synthesized squaraine compound were analyzed in a separate laboratory period and led to important pedagogical opportunities about the absorption and fluorescence of organic compounds.