Fabrication of Mn-TPP/RGO Tailored Glassy Carbon Electrode for Doxorubicin Sensing

Cancer is a long-standing disease, and the use of anticancer drugs can cause many different harmful side effects. Therefore, the quantitative analysis of anticancer drugs is crucial. Among all the analytical techniques that have been utilized for the detection of doxorubicin, electrochemical sensors have drawn exceptional consideration because they are simple, affordable, and highly sensitive. Manganese tetraphenylporphyrin decorated reduced graphene oxide (Mn-TPP/RGO), tetraphenylporphyrin decorated reduced graphene oxide (TPP/RGO), and reduced graphene oxide (RGO) nanostructure based glassy carbon electrodes (GCEs) were fabricated for the detection of doxorubicin (DOX). The synthesized materials were characterized by FTIR, scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV/vis), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Doxorubicin detection was performed using differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Among the prepared electrodes, Mn-TPP/RGO modified GCE gave an optimum peak current at pH 3. The Mn-TPP/RGO modified electrode showed significant linear response range (0.1-0.6 mM); effective sensitivity (112.09 μA mM-1 cm-2); low detection limit (63.5 μM); and excellent stability, selectivity, repeatability, and reproducibility toward doxorubicin. With differential pulse voltammetry, LoD and sensitivity were 27 μM and 0.174 μA μM-1 cm-2, respectively. Real sample analysis was also performed in human serum, and it depicted reasonable recovery results for spiked doxorubicin.

Review of research of nanocomposites based on graphene quantum dots

Graphene quantum dots (GQDs) belong to the vast and versatile family of carbon nanomaterials. Their unique position amongst versatile carbon nanoparticles (NPs) originates from the properties of quantum confinement and edge effects. GQDs are similar to conventional semiconductor QDs due to their tunable band gaps and high photoluminescence activity. However, GQDs have superior characteristics due to their excellent biocompatibility, low toxicity, good water dispersibility, large optical absorptivity, high fluorescence activity and photostability. These properties have generated significant interest in GQDs applications in various fields: nanosensor fabrication, drug delivery, photocatalysis, photovoltaics, and photodynamic therapy. Numerous GQD-based nanocomposites/nanohybrides have been synthesized and/or studied computationally. This review focuses on recent computational studies of various GQD-based nanocomposites/nanohybrides and systems which can be related to them.

Synthesis of three-dimensional nickel ferrite nanospheres decorated activated graphite nanoplatelets for electrochemical detection of vortioxetine with pharmacokinetic insights in human volunteers

An innovative electrochemical nanoprobe was developed for determination of vortioxetine (VORT), a serotonergic antidepressant drug, for the first time. The fabrication of the nanoprobe is based on decoration of a glassy carbon electrode with three-dimensional nickel ferrite nanospheres modified activated graphite nanoplatelets (3D NiFe₂O₄ NS/AGNP/GCE). The morphological characterization of the nanoprobe was carried out via scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, energy dispersive X-ray spectroscopy (EDS), N₂-adsorption-desorption isotherm, and powder X-ray spectroscopy (PXRD). In addition, the electrochemical behavior of the nanoprobe was described using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). A well-defined and irreversible peak at 0.82 V was seen at the surface of 3D NiFe₂O₄ NS/AGNP/GCE. The proposed nanoprobe exhibited outstanding electro-catalytic activity towards VORT oxidation. Under the optimized conditions, the anodic oxidation currents were linearly proportional to VORT concentration at the working range 1.8-90 nM with a LOD of 0.55 nM. The nanoprobe was used to determine VORT in pharmaceutical tablets and human plasma samples. Satisfactory recoveries and RSD percentages were obtained in the range 103.8-107.7% (RSD% = 2.7-3.1%) and 101.4-105.3% (RSD % = 2.8-3.4%) for tablets and plasma samples, respectively. Moreover, the method was used to monitor VORT during a pharmacokinetic study in human volunteers with satisfactory results. The 3D NiFe₂O₄ NS/AGNP/GCE shows excellent sensitivity, reproducibility, and selectivity towards VORT detection. The proposed electrode could be utilized as simple, rapid, and inexpensive sensing tool for routine analysis and during pharmacokinetic/pharmacodynamic investigations. Graphical abstract.

Noncovalently copper-porphyrin functionalized reduced graphene oxide for sensitive electrochemical detection of dopamine

The nanocomposite of an electron-deficient flat tetrakis-(ethoxycarbonyl) porphyrin copper(II) (Cu-TECP) and reduced grapheme oxide (RGO) was prepared and used for electrochemical detection of dopamine (DA). The prepared nanocomposite was characterized by scanning electron microscopy, Raman spectroscopy, FT-IR spectroscopy, ultraviolet-visible spectroscopy and electrochemical impedance spectroscopy. Electrochemical studies of the modified glass carbon electrode (GCE) were carried out by the cyclic voltammetry and differential pulse voltammograms (DPV) methods. The RGO/Cu-TECP/GCE exhibited enhanced electrocatalytic activity towards the detection of dopamine (DA). The detection limit was 0.58 μM, while the linear range was from 2 to 200 μM ([Formula: see text] 0.997).

Innovative Strategy Based on a Novel Carbon-Black-β-Cyclodextrin Nanocomposite for the Simultaneous Determination of the Anticancer Drug Flutamide and the Environmental Pollutant 4-Nitrophenol

In the present work, a noncovalent and eco-friendly approach was proposed to prepare a carbon-black/β-cyclodextrin (CB/β-CD) nanocomposite. CB/β-CD-nanocomposite-modified screen-printed carbon electrodes were applied for the simultaneous determination of the anticancer drug flutamide (Flut) and the environmental pollutant 4-nitrophenol (4-NP). The electrochemical performance of the proposed sensor relied on the conductivity of CB, the different binding strengths of the guests (Flut and 4-NP) to the host (β-CD), and the different reduction potentials of the nitroaromatic compounds. Fascinatingly, the proposed sensor exhibited an excellent electrochemical performance with high sensitivity, selectivity, and reproducibility. The obtained wide linear ranges were 0.05-158.3 and 0.125-225.8 μM for Flut and 4-NP. The low detection limits of 0.016 and 0.040 μM with the higher sensitivities of 5.476 and 9.168 μA μM^-1 cm^-2 were achieved for the determination of Flut and 4-NP, respectively. The practical feasibility of the proposed sensor was studied in tap-water and human-serum samples.

Synthesis, characterization and first application of covalently immobilized nickel-porphyrin on graphene oxide for Suzuki cross-coupling reaction

In this study, nickel(ii)-coordinated 5,10,15,20-tetrakis(aminophenyl)porphyrin (NiTAPP) as a macrocyclic complex was covalently grafted to the edge of graphene oxide (GO) and applied as nanocatalyst in Suzuki cross-coupling reaction.