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In this work, we examine the dependence of the fluorescence quantum yield of water-soluble CdSe/ZnS quantum dots on the local environment. The hydrophobicity of the local environment was modified by using different alkyl chain lengths in a set of oligo-ethylene glycols. Our results show that the quantum yield of CdSe/ZnS quantum dots is highest for the longest alkyl chain length, suggesting that a more hydrophobic environment is beneficial for generating bright, water-soluble quantum dots.

Contamination of food by mycotoxins occurs in minute quantities, and therefore, there is a need for a highly sensitive and selective device that can detect and quantify these organic toxins. We report the development of a rapid and highly sensitive array biosensor for the detection and quantitation of ochratoxin A (OTA). The array biosensor utilizes a competitive immunoassay format. Immobilized OTA derivatives compete with toxin in solution for binding to fluorescent anti-OTA antibody spiked into the sample. This competition is quantified by measuring the formation of the fluorescent immunocomplex on the waveguide surface. The fluorescent signal is inversely proportional to the concentration of OTA in the sample. Analyses for OTA in buffer and a variety of food and beverage samples were performed. Samples were extracted with methanol, without any sample cleanup or preconcentration step prior to analysis. The limit of detection for OTA in several cereals ranged from 3.8 to 100 ng/g, while in coffee and wine, detection limits were 7 and 38 ng/g, respectively.

Bond length alternation plays an important role in determining the conductance of molecular wires. Higher planarity of OPV makes it a better molecular wires than OPE, the measurement and theoretical calculations presented highlights an important contribution to molecular wire conductance the extent of bond length alteration along the pi-conjugated molecular backbone.

The characterization of isomeric forms of divalent hydrides of heavier group 14 elements is presented. The large co-ligands such as the beta-diketiminate ligand could stabilize divalent hydrides.

Chorismate mutase catalyzes the Claisen rearrangement of (-)-chorismate to prephenate. The importance of Arg90 is demonstrated, at the active site of Bacillus subtilis as a positively charged hydrogen bond donor involved in selective stabilization of chorismate in the transition state.

The molecular conductance of the platinum(II) complexes is significantly higher than the pi-conjugated molecular wire oligo(phenylene ethynylene)platinum(II) acetylides, which is synthesized to investigate the electrical characteristics of organometallic complexes as molecular conductors.