Immunoassay for rapid on-site detection of glyphosate herbicide.

Glyphosate is the most widespread herbicide and its global use is steadily increasing. Although glyphosate is considered to have low toxicity, its wide application has raised concerns about its effects on human health. The extensive use of glyphosate has risen a need of its continuous monitoring in drinking and surface waters to assure in accordance with the set standards. Within the present study, we have developed a novel assay for the on-site detection of glyphosate by combining flow-through technology with the high specificity of immunorecognition. The proposed biosensing system was based on the detection of fluorescence signal generated by the quantitative replacement of glyphosate in antigen-antibody complex with IgY-type anti-glyphosate antibodies on microbeads by synthetic 5-carboxytetramethylrhodamine (5-TAMRA) conjugated glyphosate. The working range of this assay was in low millimolar range and the time required for glyphosate detection around 0.5 h. The applicability of the immunoassay for glyphosate detection in surface water was tested and the biosensor results were validated with high-performance liquid chromatography.

Self-assembled SnO2 micro- and nanosphere-based gas sensor thick films from an alkoxide-derived high purity aqueous colloid precursor.

Tin oxide is considered to be one of the most promising semiconductor oxide materials for use as a gas sensor. However, a simple route for the controllable build-up of nanostructured, sufficiently pure and hierarchical SnO2 structures for gas sensor applications is still a challenge. In the current work, an aqueous SnO2 nanoparticulate precursor sol, which is free of organic contaminants and sorbed ions and is fully stable over time, was prepared in a highly reproducible manner from an alkoxide Sn(OR)4 just by mixing it with a large excess of pure neutral water. The precursor is formed as a separate liquid phase. The structure and purity of the precursor is revealed using XRD, SAXS, EXAFS, HRTEM imaging, FTIR, and XRF analysis. An unconventional approach for the estimation of the particle size based on the quantification of the Sn-Sn contacts in the structure was developed using EXAFS spectroscopy and verified using HRTEM. To construct sensors with a hierarchical 3D structure, we employed an unusual emulsification technique not involving any additives or surfactants, using simply the extraction of the liquid phase, water, with the help of dry butanol under ambient conditions. The originally generated crystalline but yet highly reactive nanoparticles form relatively uniform spheres through self-assembly and solidify instantly. The spheres floating in butanol were left to deposit on the surface of quartz plates bearing sputtered gold electrodes, producing ready-for-use gas sensors in the form of ca. 50 µm thick sphere-based-films. The films were dried for 24 h and calcined at 300 °C in air before use. The gas sensitivity of the structures was tested in the temperature range of 150-400 °C. The materials showed a very quickly emerging and reversible (20-30 times) increase in electrical conductivity as a response to exposure to air containing 100 ppm of H2 or CO and short (10 s) recovery times when the gas flow was stopped.

Combination of tert-butoxycarbonyl and triphenylphosphonium protecting groups in the synthesis of substituted hydrazines.

[structure: see text] A new reagent for the systematic synthesis of substituted hydrazines is reported. Unlike previously developed reagents, this one contains only two protecting groups, thus providing a faster approach to multisubstituted derivatives. The selective introduction of alkyl and acyl groups is illustrated by a few examples. Also a new fast method for the deprotection of the triphenylphosphonium group is presented.

C18 Dienes as attractants for eighteen clearwing (Sesiidae), tineid (Tineidae), and choreutid (Choreutidae) moth species.

By screening singly and binary mixed 2,13- and 3,13-octadecadien-yl acetates and alcohols (2,13- and 3,13-18: Ac/OH)in Lithuania, Armenia, Azerbaijan, Turkmenistan, Ukraine, and the far east of Russia, sex attractants were discovered for 12 Sesiidae, four Tineidae, and one Choreutidae moth species. Males ofSesia yezoensis andBembecia puella as well asNemapogon flavifrons were attracted by mixture ofZ3,Z13-18:Ac/OH in a ratio of 9∶1,Pyropteron sp. n. by the same mixture (ratio 1∶9),Bembecia romanovi andB. zuwandica byZ3,Z13-18:Ac andE3,Z13-18:Ac (9∶1),Synanthedon caucasicum by the same mixture in the opposite ratio (1∶9),B. scopigera by 23,213-18:Ac andE2,Z13-18:OH in a ratio 9∶1,Synasphecia triannuliformis byZ3,Z13-18:OH andE3,Z13-18:OH (9∶1),Similipepsis takizawai andArchimeessia sp. n. by E3,Z13-18:OH andE2,Z13-18:Ac (1∶1),Prochoreutis sechestediana by a mixture ofE3,Z13-18:Ac plusE2,Z13-18:OH (1∶),Microsphecia brosiformis by E3,Z13-18:Ac,Synanthedon conopiformis by the analogous alcohol,Synanthedon scoliaeformis andNemaxera betulinella byE2,Z13-18:Ac,Triaxomera fulvimitrella byZ3,Z13-18:Ac. An analogous alcohol component is essential for the attraction ofB. ichneumoniformis males. Inhibitors forB. romanovi, B. scopigera andB. zuwandica attraction were discovered. Preliminary data on attractants for six other species as well as on the diurnal rhythm of sexual activity of three species are presented. A new method for the stereoselective synthesis of 3,13-18:Ac/OH andE2,Z13-18:Ac/OH is described.

Novel galanin receptor ligands.

Galanin is a neuroendocrine peptide which is 29/30 amino acids in length and is recognised by G-protein-coupled central nervous system receptors via its N-terminus. We synthesised several galanin receptor ligands and fragments around C-terminal extensions of galanin(1-13) to yield chimeric peptides with C-terminals corresponding to bioactive peptides like bradykinin(2-9), mastoparan, neuropeptide Y(25-36) or substance P(5-11), respectively. We also synthesised short galanin analogs in which galanin(1-13) was C-terminally elongated with Lys14; different pharmacologically active small molecules were then attached to the epsilon-amino group of Lys14. Several cysteine-substituted linear and ring closed analogs of galanin(1-9) and galanin(1-16) were also synthesised. The equilibrium binding constants for these peptides at hypothalamic galanin receptors were determined and found in the subnanomolar to micromolar range. The large number of peptides and their binding affinities presented here permit structure-activity relationship analysis of peptide-type ligands to galanin receptors.