Calixarene assembly with enhanced photocurrents using P(SNS-NH2)/CdS nanoparticle structure modified Au electrode systems.

Two novel calix[n]arene-adorned gold electrodes producing high photocurrent intensities were successfully constructed by embedding gold electrode surfaces with both P(4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine) conducting polymer and 4-mercaptoboronic acid-functionalized semiconductor CdS nanoparticles to facilitate the binding of calix[n]arene sulfonic acids with nanoparticles. This structure enabled an electron transfer cascade that both induced effective charge separation and efficiently generated photocurrent. The prepared electrodes were used to generate photocurrent by relying on the host-guest interactions of guests Br3(-) and I3(-), which if positioned well in the system was able to fill electron-hole pairs of CdS nanoparticles. As a result, host calixarene derivatives crucially held Br3(-) and I3(-) ions at a substantial distance from CdS nanoparticles. Furthermore, the effects of various calixarenes on the photocurrent obtained indicate that the generation of photocurrent intensities by the system depends on the cavity sizes of calixarene derivatives, which provide an essential center for Br3(-) and I3(-) ions.

Synthesis of 1,4-bis(indolin-1-ylmethyl)benzene derivatives and their structure-activity relationships for the interaction of human carbonic anhydrase isoforms I and II.

Several 1,4-bis(indolin-1-ylmethyl)benzene-based compounds containing substituents such as five, six and seven cyclic derivatives on indeno part (9a-c) were prepared and tested against two members of the pH regulatory enzyme family, carbonic anhydrase (CA). The inhibitory potencies of the compounds at the human isoforms hCA I and hCA II targets were analyzed and KI values were calculated. KI values of compounds for hCA I and hCA II human isozymes were measured in the range of 39.3-42.6µM and 0.17-0.29µM, respectively. The structurally related compound indole was also tested in order to understand the structure-activity relationship. Most of the compounds showed good CA inhibitory efficacy. In silico docking studies of these derivatives within hCA I and II were also carried out and results are supported the kinetic assays.

Calculation of conductive polymer-based SO2 and SO3 gas sensor mechanisms by using the DFT method.

In this study, we carried out with the DTP (dithieno(3,2-b:2,3-d) pyrrole) molecule which is a member of the conductive polymer class that is one of the topics that have been studied prevalently in recent times, and the density functional theory's (DFT) calculation methods were used to shed light on the sensor mechanisms of its interactions with SOx (SO2 and SO3) sulfur oxides. The changes in the geometric and electronic characteristics of a sensor mechanism designed with the DTP molecule when it encountered sulfur oxides were examined. With these changes, the usability of DTP as a sensor material was proven. DTP sensor applications using this method were not investigated in previous studies. The B3LYP 6-31 G(d) levels of DFT were used in the calculations. In the calculations, during the interaction between analyte (SO2-SO3) and the conductive polymer DTP (dithieno(3,2-b:2,3-d) pyrrole), especially, the changes in its geometric and electronic structures were observed. With these changes that were observed in the geometric structure, as a result of the interaction between the conductive polymer and gas molecules, the resistance on the polymer's main chain decreased, and conductivity increased. Calculations on the bandgap on HOMO-LUMO energy levels were observed to decrease. Thus, the structural conductivity of the molecule increased. Additionally, the experiments showed that, as a result of interaction with gas molecules, the bandgap in the ionization potential, electron affinity, and HOMO-LUMO energy levels varied. These variations showed the detection mechanisms for sulfur oxides by the DTP (dithieno(3,2-b:2,3-d) pyrrole) molecule that may be used to design sensors.

Folic-Acid-Modified Conducting Polymer: Electrochemical Detection of the Cell Attachment.

Here, postfunctionalization and bioapplication of a π-conjugated polymer named 4-[4H-dithieno(3,2-b:2',3'-d)pyrrol-4-yl]aniline (DTP-aryl-NH2 ) are reported, which is successfully synthesized via electropolymerization onto the glassy carbon electrode. Folic acid (FA) is used to modify the amino functional polymer via N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide chemistry for the further steps. The selective adhesion of folate receptor positive cells on the surface is followed by the electrochemical methods. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize stepwise modification of the electroactive surface. After optimization studies such as scan rate during the polymer deposition, FA amount for the efficient surface targeting, incubation time with the cells etc., analytical characterization is carried out. The surface morphologies at each step are imaged by using fluorescence microscopy.