Novel decorated aluminium(iii) phthalocyanine complex with the application of MWCNTs on electrodes: electrochemical non-enzymatic oxidation and reduction of glucose and hydrogen peroxide

Abstract

In this study, we performed the physicochemical and electrochemical characterization of a decorated macrocyclic aluminium(III) phthalocyanine complex (AlTMQNCAPc). Subsequently, the AlTMQNCAPc@MWCNT/GC electrode was used for the electrochemical detection of glucose and hydrogen peroxide (H₂O₂) by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA). Moreover, the limit of detection, linear range, and sensitivity for glucose and H₂O₂ were investigated (CV: 2.5 nM L⁻¹ and 25 nM L⁻¹, 50–500 μM, 0.052 and 0.072 μA μmol cm⁻²; DPV: 3.1 nM L⁻¹ and 18 nM L⁻¹, 50–500 μM, 0.062 and 0.066 μA μmol cm⁻² and CA: 10 nM L⁻¹ and 20 nM L⁻¹, 50–500 μM, 0.098 and 0.07 μA μmol cm⁻², respectively). In addition, the AlTMQNCAPc@MWCNT/GC electrode showed good selectivity for the detection of glucose and H₂O₂ in the presence of common interfering substances, such as AA, DA, UA, glycine, L-cysteine, nitrite, Pb(II), Cd(II), Cu(II), Co(II), Hg(II), Zn(II), and glucose. For the detection of glucose and H₂O₂, the kinetic parameters, including the electron transfer coefficient and catalytic reaction rate constant, were also established. Finally, for usage in practical applications, the modified electrode was employed to achieve the quantitative detection of glucose and H₂O₂ in human urine and commercial samples of 3% H₂O₂, respectively.