A voltammetric sensor based on mixed proton-electron conducting composite including metal-organic framework JUK-2 for determination of citalopram

Abstract

A voltammetric sensor has been developed based on glassy carbon electrode (GCE) modification with nanocomposite consisting of manganese-based metal-organic framework (JUK-2), multi-walled carbon nanotubes (MWCNTs), and gold nanoparticles (AuNPs) for detection of citalopram (CIT). The composition and morphology of JUK-2-MWCNTs-AuNPs/GCE were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy dispersion spectroscopy (EDS), and scanning electron microscopy (SEM). The electrochemical properties investigated using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) indicated that the fabricated hybrid material exhibits the properties of mixed ion-electron conductor (MIEC). Using staircase voltammetry (SCV), under optimized conditions, the fabricated sensor shows a linear response in three CIT concentration ranges, 0.05–1.0, 1.0–10.0 and 15.0–115.0 μmol L−1, with a detection limit of 0.011 μmol L−1. The JUK-2-MWCNTs-AuNPs/GCE was successfully employed for the determination of CIT in pharmaceutical, environmental waters, and biological samples with satisfactory recoveries (98.6–104.8%). Graphical abstract

Electrochemical Characterization of Modified Glassy Carbon Electrodes for Non-Enzymatic Glucose Sensors

“…The heterogenic rate constant of the electrode reaction k was determined using Equation (3) [ 20 ]: where D O/R is the diffusion coefficient for [Fe(CN) 6 ] 3−/4− redox species ( D O/R = 7.2 × 10 −6 cm 2 /s).…”

“…In the case of chitosan- and Nafion-based electrodes, these polymers blocked some of them, as also indicated by decreased values of EASA and higher Warburg impedance modulus [ 14 , 46 ]. The small background current reducing LOD and LOQ for Cu-PVP/GCE may be explained by its lower CPE CT compared to that of other electrodes [ 20 ].…”

“…This technique offers the possibility of studying the state of the electrode during various processes that occur in electrochemical experiments, such as adsorption, charge, and mass transport [ 12 , 13 , 14 , 15 ]. Moreover, the changes introduced by the modification of the substrate electrode with various conductive or nonconductive materials can be assessed using this technique [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Another field of application of EIS is the direct investigation of the sensors’ analytical response [ 15 , 16 , 17 , 18 , 19 ].…”

Computational Modelling and Sustainable Synthesis of a Highly Selective Electrochemical MIP-Based Sensor for Citalopram Detection

“…Its mechanism of action is based on blocking the reuptake of the neurotransmitter serotonin into nerve terminals of donor cells, thereby potentiating the serotonergic activity [ 11 , 12 ]. This compound is a racemic mixture of R(−) and S(+) enantiomers, but its desired pharmacological effect appears to reside mainly in the S-enantiomer [ 13 , 14 ]. In comparison with the previously introduced tricyclic antidepressants, CTL offers advantages owing to its therapeutic profile, superior acceptability, and safety, which justifies its popularity in the treatment of major depressive disorders [ 3 , 15 , 16 ].…”

The Use of an Acylhydrazone-Based Metal-Organic Framework in Solid-Contact Potassium-Selective Electrode for Water Analysis

“…However, some of the strategies for the improvement of the electric conductivity of MOFs are known. They include procedures such as the incorporation of ionic guest species, modification of the material with the use of redox-active or conductive compounds [22][23][24]. The use of MOFs in potentiometry is rare and only a few publications on this topic can be found in the literature.…”