Novel Polymer Supported Phthalocyanine Nanosensors and Analytical Application

Abstract

In this study, a novel PCL-based polymer (6) containing A3B-type zinc phthalocyanine was synthesized as a result of the ring-opening polymerization of epsilon-caprolactone (epsilon-CL), in which A3B-type zinc phthalocyanine (5) prepared by condensation method of two different phthalonitrile precursor molecules, 4-(3-hydroxypropylmercapto)phthalonitrile (3) and 4-tert-butylphthalonitrile (4), in 3:1 molar ratios used as the initiator. (6) was synthesized in three stages; the synthesis of 4-(3-hydroxypropylmercapto)phthalonitrile (3) (i), novel A3B-type zinc phthalocyanine (ii), PCL-based polymer (6) containing A3B-type zinc phthalocyanine (iii). The novel compounds (5) and (6) were characterized by spectroscopic (FTIR, 1H NMR. 13C NMR and UV-vis), DSC and chromatographic (GPC) methods. After that, a new generation hybrid material (PcY-MWCNTP and PcX-MWCNTP) was developed by treating bare Pc (PcX) and polymer-based Pc (PcY) with carboxyl-functionalized multi-walled nanocarbon tube powders (COOH-MWCNTPs). This new nanomaterial was also coated on the glassy carbon electrode (GCE) surface using the drip-dry technique. The sensitivities of the developed both nanosensor in the determination of rifaximin were investigated at first time. Compared to the other electrode, PcX-MWCNTP/GCE significantly increased the anodic signal of rifaximin (approximately 5-fold) and shifted the peak potential to the less positive region. A wide working range from 0.25 mg/L to 10.0 mg/L was obtained, and the limit of detection (LOD) was calculated as 48 mu g/L by differential pulse voltammetry (DPV). Finally, the electrochemical method was successfully applied analytically in natural samples to test its accuracy and precision by using PcX-MWCNTP/GCE.