As a consequence of organophosphorus (OP) toxins posing a threat to human life globally, organophosphorus hydrolase (OPH) has become the enzyme of choice to detoxify such compounds. Organophosphorus hydrolase was covalently immobilized onto a quartz substrate for utilization in paraoxon detection. The substrate was cleaned and modified prior to chemical attachment. Each modification step was monitored by imaging ellipsometry as the thickness increased

Abeta(31-35) peptide and control peptides as well as full length Abeta(1-40) and Abeta(1-42) peptides were labelled with luminescent CdSe/ZnS quantum dots (QDs) to observe the morphology of amyloid fibers. A comparison was made between QDs and an organic dye, namely Dansyl group, which showed that the QDs present a much better contrast for imaging than the organic dye.

Herein, we report the surface modification of quartz with a coumaryl–aza-crown-6 derivative to detect Saxitoxin using fluorescence enhancement through Photoinduced Electron Transfer and the sensitivity with this system approaches the limit of the mouse bioassay which is the current benchmark for Saxitoxin detection.

Peptidolipid C18H35O (stearoyl)-Phe-Trp-Ser-His-Glu (peptidolipid A) was synthesized and spread at the air-water interface to study the interaction with an organophosphorus compound. Paraoxon, sodium dihydrogen phosphate, or 4-nitrophenyl phosphate disodium was added to the subphase, but only paraoxon changed the surface pressure-area (-A) isotherm of peptidolipid A. This indicated a specific interaction between paraoxon and peptidolipid A. To clarify

This paper focuses on the examination of the Photoinduced Electron Transfer (PET) and Internal Charge Transfer (ICT) for two coumarin derivatives, namely 7-methoxycoumarin-4-methyl-1-aza-18-crown-6 and di(7-methoxycoumarin-4-methyl)-1,10-diaza-18-crown-6. The spectroscopic properties were investigated by UV-Vis and fluorescence spectroscopies. It was found that a dual mechanism explains the fluorescence enhancement and blue shift in the presence

Newly designed poly(amido amine) dendrimers, which have an azacrown core, hexyl spacers, and methyl ester terminals (aza-C6-PAMAM dendrimer), were spread at the air-water and air-silver nanoparticle suspension interfaces, and their film structures were examined by surface pressure-area (pi-A) and surface potential-area (deltaV-A) isotherms and epifluorescence microscopy. It was revealed that generation (G) 1.5 aza-C6-PAMAM dendrimer on a water subphase

The fibril formation process of a synthetic peptidolipid compound in a Langmuir monolayer at the air-water interface has been analyzed by surface pressure and surface dipole moment-area isotherms, followed by infrared spectral analysis of related Langmuir-Blodgett films. Thus far, the analysis of randomly oriented molecular assemblies has been a difficult matter, especially for spectroscopic measurements. In the present study, the Langmuir film isotherms

The accumulation of ß-amyloid peptide (Aß) in the human brain is known to be the major cause that drives Alzheimer's disease pathogenesis. Aß, a 39-42 amino acid peptide, is the cleavage product of amyloid precusor protein in the hydrophobic transmembrane region. The present study employs a two-dimensional (2D) approach. Two synthetic peptidolipids, C18-IIGLM-OH and C18-IIGLM-NH2, are selected based on the fragment 31-35 of Aß which is recognized

Virgil Percec, P. Roy Vagelos Professor of Chemistry at the University of Pennsylvania, has contributed to the development of novel methods of polymer synthesis for both covalent and supramolecular systems ranging from liquid-crystalline polymers to dendrimers. "The trademarks of his work include amazing creativity, great breadth, vision, thoroughness, and reliability," remarks Jean M. J. Fréchet, professor of chemistry at the University of California,

Since luminescent CdSe quantum dots (QDs) have shown great potential in biological labeling, the surface chemistry behavior of QDs at interfaces is of great research interest. In the present study, CdSe QDs with green luminescence were modified with hydrophobic chains of varying lengths [from C6 to C18]. These modified QDs can be utilized to form stable monolayers at the air/water interface. Surface pressure-area isotherms of modified QDs have been