complex based on Ntripodal ligand immobilized in a Nafion® film for biomimetic detection of catechols: Application to dopamine. Electrochimica Acta, Elsevier, 2016, 221, pp.80-85 AbstractA complex based on bis-pyrazolyl N-tripodal ligand known to present a good catalytic activity for the oxidation of 3,5-di-tert-butylcatechol is used to prepare a novel biomimetic sensor for the determination of catechol derivatives. The modified electrode prepared by encapsulation of the complex in a Nafion ® film leads to an electrochemical signal 4.4 times higher than with a glassy carbon electrode for dopamine detection in pH 7 medium. After optimization of the conditions used to immobilize the catalyst on the electrode surface, a calibration curve was obtained with linearity in the range of 30 to 320 mol L -1 and a detection limit of 8 mol L -1 .The sensor was not affected by ascorbic acid and uric acid in similar concentrations to dopamine and its electrochemical response was stable after 40 determinations. The biomimetic sensor can also be used for the detection of other catechol derivatives.

The inhibitive effect of 2-thiophene carboxaldehyde (TCAl) on zinc corrosion in 1 M H 3 PO 4 solutions has been studied by weight loss, potentiodynamic polarisation and open-circuit potential (OCP) methods. The obtained results revealed that TCAl is an effective corrosion inhibitor for zinc in H 3 PO 4 solutions. Inhibition efficiency values obtained from gravimetric and electrochemical measurements were in good agreement. The inhibition efficiency increases with increasing inhibitor concentration and decreases with increasing temperature. Potentiodynamic polarisation studies showed that TCAl acts as a mixed type inhibitor. Scanning electron microscopy (SEM), OCP measurements and the thermodynamic data of dissolution and adsorption processes showed that inhibition of zinc corrosion in phosphoric acid solutions by TCAl is due to the formation of a physisorbed film on the zinc surface. Adsorption of the compound studied on zinc surface obeys to Langmuir adsorption isotherm.

No abstract