Poly-Phthalocyanine–Doped Graphene Oxide Nanosheet Conjugates for Electrocatalytic Oxidation of Drug Residues

Abstract

Donor and acceptor phthalocyanine molecules were copolymerized and linked to graphene oxide nanosheets through amidation to yield electrocatalytic platforms on glassy carbon electrodes. The platforms were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, UV/Vis spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The fabricated electrochemical catalytic surfaces were then evaluated toward electrocatalytic detection of ascorbic acid and tryptophan. These were characterized by a wide linear dynamic range and low limits of detection and quantification of 2.13 and 7.12 µM for ascorbic acid and 1.65 and 5.5 µM for tryptophan, respectively. The catalytic rate constant was 1.86 × 104 and 1.51 × 104 M−1s−1 for ascorbic acid and tryptophan, respectively. The Gibbs energy for catalytic reactions was −17.45 and −14.83 kJ mol−1 depicting a spontaneous reaction on the electrode surface. The sensor platform showed an impressive recovery when applied in real samples such as fresh cow milk, in the range 91.71–106.73% for both samples. The developed sensor therefore shows high potential for applicability for minute quantities of the analytes in real biological samples.

Graphene quantum dot-porphyrin/phthalocyanine multifunctional hybrid systems: from interfacial dialogue to application

“…71,[152][153][154] These problems can be easily circumvented by constructing a hybrid system of GQDs-Pp/Pc via interface engineering, overcoming the inherent problems associated with porphyrinic compounds and enhancing the efficacy of GQDs for various applications. 131,[155][156][157][158]193 The functionalization of GQDs is an efficient strategy to enhance the basic properties of nanocomposites, resulting in several additional optico-physicochemical properties for wider applications. 1,42,43,85,103,159,160 Currently, porphyrins are applied in optics and medicine, such as nonlinear absorbers or PDT, which increasingly require the use of far-red absorbing dyes.…”