No abstract

N,N′‐bis(2‐hexyl)‐2,6‐(3,4 ethylenedioxythiophene)‐1,4,5,8‐naphthalenimide (ENDI) monomer was electropolymerized on pencil graphite electrode (PGE) and used as a biosensor for glucose immobilization for the first time. After electropolymerization of ENDI monomer on PGE (AuNPs/PENDI/PGE), the intensity of the current signal was improved by using gold nanoparticles (AuNPs). The immobilization of the glucose oxidase (GOx) enzyme was carried out by using the cross‐linking reagent glutaraldehyde (GA) due to the strong π‐π* interaction of the poly‐ N,N′‐bis(2‐hexyl)‐2,6‐(3,4 ethylenedioxythiophene)‐1,4,5,8‐naphthalenimide (PENDI) polymer. GOx/AuNPs/PENDI/PGE designed biosensor, was characterized by a wide linear glucose determination range between 0.0009–0.33 mM with a limit of detection of 0.0407 mM and a sensitivity of 0.172 μA/mMcm2. Herein we have shown that GOx/AuNPs/PENDI/PGE biosensor effectively provides the enzyme immobilization and very effective for glucose determination in commercial samples.

A new monomer named 4-(dihexylamino)9,12-di(thiophen-2-yl)-7H-benzo [de] benzo [4,5]imidazo[2,1-a]isoquinolin-7-one (ThBN) is synthesized and used as a potential glucose biosensor after electropolymerization of the ThBN on the graphite pencil electrode. The amount of glucose is determined according to the decrease in the amount of oxygen by using cyclic voltammetry technique. Herein, conjugated polymer of ThBN is used as a immobilization matrix. The synthesized PThBN is found to be effective enzymatic biosensor having wide linear glucose determination range between 2.975 Â 10 À3 and 2.087 mM with a limit of detection of 0.0304 mM and a sensitivity of 0.1326 μA/mM cm 2 . This potential enzymatic biosensor has been also tested in commercial samples and found to be useful to detect the glucose concentration.

No abstract

Boron is widely used in various areas of modern technology. Due to the environmental problems arising during the production and use, the studies on the removal and recovery of boron from wastewater have been increased recently. Membrane distillation (MD) system is smaller in size with respect to other common distillation systems and needs lower operating temperatures. In addition, the equipment costs are reduced and the safety of the process increases since it operates at lower pressures. Moreover, the membrane distillation process can remove pollutants from water without using chemicals. In this study, boron rejection from aqueous solutions and wastewater was investigated by using direct contact membrane distillation (DCMD) system where both surfaces of a porous hydrophobic membrane were in contact with liquid streams. The effects of various parameters (pH, feed concentration, feed temperature, etc.) on boron rejection were investigated and the highest boron rejection was found to be 50 % when pH=10 at 50 °C and with feeding by a pump of 54 rpm. According to the test results of wastewater from Kırka Borax treatment plants, the mean distillate fluxes were found as 13, 16 and 14 L m -2 h -1 at the feed temperatures of 30, 40 and 50 °C, respectively. The boron removal percentages were found to be 47, 64 and 48 % at 30, 40 and 50 °C, respectively. It was observed in the XRD spectra that the crystals in wastewater mainly consist of Na2B(OH)4Cl and Mg2B2O5 structures.