Impact of bridge heterology on functional parameters of ELISA for 17α-methyltestosterone

In this study, we have developed bridge heterologous ELISA for the detection of 17α- Methyltestosterone by incorporating aromatic spacers between 17α-Methyltestosterone-3-Carboxymethyloxime and Horseradish peroxidase label through N-hydroxysuccinimide mediated carbodiimide reaction method. The immunogen 17α-Methyltestosterone-3-Carboxymethyloxime-Bovine serum albumin used to generate the antibody was also prepared by the N-hydroxysuccinimide mediated carbodiimide reaction without using any spacer. We have studied the impact of bridge/aromatic spacers on functional parameters i.e. sensitivity, affinity and ED50 of the bridge heterologous assay and compared it with homologous assay. The five combinations of bridge heterologous assay using 17α-Methyl testosterone-3-CMO-BSA antiserum and 17α-MT-3-CMO-4,4'-Diaminodiphenyl sulphide-HRP, 17α MT-3-CMO-4,4'-Oxydianiline-HRP, 17α-MT-3-CMO-Benzidine-HRP, 17α- MT-3-CMO-p-Phenylenediamine-HRP and 17α-MT-3-CMO-Dapson-HRP enzyme conjugates were evaluated. Out of these five combinations, the combination 17α-MT-3-CMO-BSA with 17α-MT-3-CMO-Benzidine-HRP showed the best results. Sensitivity, affinity and ED50 were improved and found to be 0.02 ng/mL, 0.086 × 10-8 L/mol and 2.95 ng/mL than homologous assay where Sensitivity, affinity and ED50 were 0.11 ng/mL, 0.02 × 10-8 L/mol and 5.78 ng/mL respectively. The cross-reactivity for this bridge heterologous assay combination was seen with only 4 steroids (6-hydrotestosterone- 6%, Testosterone-5.14%, Danazol-0.9% and Nandrolone-0.85%) instead of eight steroids (6-hydrotestosterone-43.75%, Testosterone-38.3%, Danazol-25.14%, Androstenediol-19.16%, Nandrolone-19%, Metandienone-5%, Androstenedione-3.52%, and 17α dimethyltestosterone-2%) as in homologous assay out of 59 structurally related steroids. Thus, the results of this study conclude that the incorporation of aromatic spacer (bridge) in enzyme conjugate has a crucial role in improving sensitivity, specificity, ED50 and affinity of the developed assay. The assay was then studied for parameters such as recovery (97.4%-108.6%), precision (Inter and Intra-assay coefficient of variation <10%), correlation coefficient (R2 = 0.96) by comparing with the commercial kit and validated by measuring levels of 17α- methyltestosterone in rat serum after administering them.

Intramolecular alkyne–dithiolium cycloaddition: a joint experimental and DFT mechanistic study

The intramolecular alkyne–dithiolium cycloaddition reactions were found to occur through either a concerted or stepwise pathway, depending on the conjugation degree of the alkynyl unit.

EF, Zhao Y. Redox-dependent properties of DTF-endcapped π-oligomers

Solid films of electroactive π-conjugated oligomers show distinct redox behaviour from that in solution, with interesting morphological changes accompanying oxidation.

Tetrathiafulvalene vinylogues as versatile building blocks for new organic materials

Although tetrathiafulvalene (TTF) and its derivatives have been extensively studied as important organic electronic materials over the past half century, tetrathiafulvalene vinyl-ogues (TTFVs) still remain a relatively underdeveloped branch in the family of TTF derivatives. Our recent work has investigated the synthesis and characterization of a class of diphenyl-substituted TTFVs carrying alkynyl functionality. The unique conformational and redox properties of such TTFV derivatives along with the versatile chemistry enabled by acetylenic groups (e.g., metal-catalyzed coupling and click reactions) have led us to a variety of functional molecular architectures ranging from oligoynes, polymers, and molecular tweezers, to macrocycles. Property studies of these new TTFV-based molecular materials point to appealing applications in molecular electronics and optoelectronics.