Comparative study on sensing and optical properties of carbazole linked novel zinc(II) and cobalt (II) phthalocyanines

Abstract

In the current work, symmetrically carbazole linked Zn(II) and Co(II) phthalocyanines (Pcs) have been succesfully synthesized and characterized through Fouirer Transform Infrared (FT-IR), Ultraviolet–visible (UV–vis) spectroscopies, Matrix-assisted laser desorption - ionisation-time of flight mass spectrometry (MALDI-TOF MS) along with proton and carbon Nuclear Magnetic Resonance (1H and 13C- NMR) spectroscopies. The electrochemical performance of the targeted metallo- phthalocyanines was demonstrated with cyclic voltammetry (CV), and square wavevoltammetry (SWV). The final phthalocyanines were used as hybrid materials for the preparation of the modified glassy carbon electrode (GCE). The hybrid materials were then deposited on GCE via an electropolymerization or electrodeposition method. The surface morphologies of the hybrid electrodes were investigated using scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDX). IR, UV–vis and Raman spectroscopies were carried out to evaluate the surface of the hybrid electrodes. The N-ethylcarbazole moiety and redox active Zn(II), Co(II) metal centers were employed in order to improve the sensing performance of targeted compounds. Furthermore, hybrid material-graphene modified GCEs have been designed to compare and rise the analytical activity. The sensing properties of the designed electrodes was investigated to detect electrochemically active biomolecules namely, dopamine (DA), ascorbic acid (AA), and uric acid (UA) in both phosphate buffered saline (PBS) and tap water sample. The Grp/ Ply(Car-CoPc)/GCE electrode was only detected DA with a limit of detection (LOD) of 16 nM. On the other hand, LOD values of Grp(Car-CoPc)/GCE were determined by voltammetric analyses as 3.38 μM and 0.62 μM for AA and UA, respectively. Sensing performances of the designed electrodes were eximined for the concurrently determination of DA and UA using differential pulse voltammetry (DPV) method.