Voltammetric detection of sumatriptan in the presence of naproxen using Fe3O4@ZIF-8 nanoparticles modified screen printed graphite electrode

Rapid and naked-eye colorimetric detection of ultra trace sumatriptan in drinking water, saliva, and human urine samples based on the aggregation of gold nanoparticles

In this study, the determination of sumatriptan (SUM) was performed using a simple, rapid, and precise colorimetric method based on the surface plasmon resonance (SPR) feature of gold nanoparticles (AuNPs). By adding SUM, the aggregation was observed in AuNPs with red-to-blue color shifts. The size distribution of NPs was estimated before and after adding SUM via dynamic light scattering (DLS), which was found to be 15.34 and 97.45 nm, respectively. Characterization of AuNPs, SUM, and AuNPs in combination with SUM was investigated using transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Examining the effect of pH, the volume of buffer, the concentration of AuNPs, interaction time, and ionic strength revealed that their optimal values were 6, 100 μL, 5 μM, 14 min, and 12 μg L-1, respectively. The suggested method was able to determine the amount of SUM in a linear range of 10 to 250 μg L-1 with a limit of detection (LOD) and limit of quantification (LOQ) of 0.392 and 1.03 μg L-1, respectively. This approach was successfully applied to determine SUM in drinking water, saliva, and human urine samples with relative standard deviations (RSD) lower than 0.03%, 0.3%, and 1.0%, respectively.

Electro-oxidation sensing of sumatriptan in aqueous solutions and human blood serum by Zn(II)-MOF modified electrochemical delaminated pencil graphite electrode

An electrochemical sensory platform is presented for determination of sumatriptan (SUM) in aqueous solutions and human blood serum. A pencil graphite electrode (PGE) was electrochemically delaminated by cyclic voltammetry technique, and then further modified using nanoparticles of a zinc-based metal-organic framework (Zn(II)-MOF). The fabricated Zn(II)-MOF/EDPGE electrode was utilized for sensitive electrochemical detection of SUM via an electro-oxidation reaction. The Zn(II)-MOF was hydrothermally synthesized and characterized by various techniques. The electrochemical delamination of PGE results in a porous substrate, facilitating the effective immobilization of the modifier. The designed sensor benefits from both enhanced surface area and an accelerated electron transfer rate, as evidenced by the chronocoulogram and Nyquist plots. Under optimized conditions, the developed sensor exhibited a linear response for 0.99-9.52 µM SUM solutions. A short response time of 5 s was observed for the fabricated sensor and the detection limit was found to be 0.29 μM. Selectivity of Zn(II)-MOF/EDPGE towards SUM was evaluated by examining the interference effect of codeine, epinephrine, acetaminophen, ascorbic acid, and uric acid, which are commonly found in biological samples. The developed sensor shows excellent performance with recovery values falling within the range of 96.6 to 111% for the analysis of SUM in human blood serum samples.

A novel nanocomposite containing zinc ferrite nanoparticles embedded in carboxymethylcellulose hydrogel plus carbon nitride nanosheets with multifunctional bioactivity

A novel and biologically active nanobiocomposite is synthesized based on carbon nitride nanosheet (g-C3N4) based carboxymethylcellulose hydrogels with embedded zinc ferrite nanoparticles. Physical-chemical aspects, morphological properties, and their multifunctional biological properties have been considered in the process of evaluation of the synthesized structure. The hydrogels' compressive strength and compressive modulus are 1.98 ± 0.03 MPa and 3.46 ± 0.05 MPa, respectively. Regarding the biological response, it is shown that the nanobiocomposite is non-toxic and biocompatible, and hemocompatible (with Hu02 cells). In addition, the developed material offers a suitable antibacterial activity for both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

Glassy Carbon Electrode Modified with CB/TiO2 Layer for Sensitive Determination of Sumatriptan by Means of Voltammetry and Flow Injection Analysis

Sumatriptan is an organic chemical compound from the tryptamine group. It is used as a medicine for migraine attacks and in the treatment of cluster headaches. In this work, a new voltammetric method is proposed for highly sensitive SUM determination, using glassy carbon electrodes modified with carbon black and titanium dioxide suspension. The novelty of the presented work is the usage of the mixture of carbon black and TiO₂ as glassy carbon electrode modifier for the first time for SUM determination. The mentioned sensor was characterized by great repeatability and sensitivity of measurements, which resulted in the obtention of a wide range of linearity and a low detection limit. The electrochemical properties of the CB-TiO₂/GC sensor was characterized using the LSV and EIS method. The effect of different factors on the SUM peak, such as supporting electrolyte type, preconcentration time and potential, or influence of interferents, were tested using the square wave voltammetry technique. The linear voltammetric response for the analyte was obtained in the concentration range of 5 nmol L^-1 to 150 μmol L^-1 with a detection limit of 2.9 nmol L^-1 for a preconcentration time of 150 s in the 0.1 mol L^-1 phosphate buffer pH 6.0. The proposed method was successfully applied for highly sensitive sumatriptan determination in complex matrices, such as tablets, urine, and plasma, with a good recovery parameter (94-105%). The presented CB-TiO₂/GC electrode is characterized by great stability, it was used for 6 weeks without significant changes in the SUM peak current. Amperometric and voltammetric measurements of SUM under the flow injection conditions were also performed to indicate the possibility of its fast and accurate determination with a time of single analysis of approx. 30 s.

Magnetic carboxymethyl cellulose-silk fibroin hydrogel: a ternary nanobiocomposite exhibiting excellent biological activity and in vitro hyperthermia of cancer therapy

In this work, a magnetic nanobiocomposite scaffold based on carboxymethylcellulose (CMC) hydrogel, silk fibroin (SF), and magnetite nanoparticles was fabricated. The structural properties of this new magnetic nanobiocomposite were characterized by various analyses such as FT-IR, XRD, EDX, FE-SEM, TGA and VSM. According to the particle size histogram, most of the particles were between 55-77nm and the value of saturation magnetization of this nanobiocomposite was reported 41.65emu.g^{- 1}. Hemolysis and MTT tests showed that the designed magnetic nanobiocomposite was compatible with the blood. In addition, the viability percentage of HEK293T normal cells did not change significantly, and the proliferation rate of BT549 cancer cells decreased in its vicinity. EC50 values for HEK293T normal cells after 48h and 72h were 3958 and 2566, respectively. Also, these values for BT549 cancer cells after 48h and 72h were 0.4545 and 0.9967, respectively. The efficiency of fabricated magnetic nanobiocomposite was appraised in a magnetic fluid hyperthermia manner. The specific absorption rate (SAR) of 69W/g (for the 1mg/mL sample at 200kHz) was measured under the alternating magnetic field (AMF).

A new copper-supported zinc ferrite as a heterogeneous magnetic nanocatalyst for the synthesis of bis(pyrazolyl)methanes and oxidation of sulfides

In this paper, we report the synthesis of ZnFe₂O₄@SiO₂@APTES@DHBS-Cu as a novel magnetic nanocatalyst, in a mild and green environment. The structure of the described magnetic compound was characterized by different physicochemical techniques including XRD, EDS, AAS, SEM, FT-IR, X-ray elemental mapping, TGA, and VSM analyses. The prepared magnetic nanoparticles exhibit excellent catalytic activity in synthesizing bis (pyrazolyl)methanes and oxidation of sulfide derivatives under green conditions. The heterogeneous nature of the catalyst was confirmed via the hot filtration experiment. Further, ZnFe₂O₄@SiO₂@APTES@DHBS-Cu showed high efficiency and reusability that could be reused for at least five consecutive runs.

Glassy Carbon Electrode Modified with N-Doped Reduced Graphene Oxide Sheets as an Effective Electrochemical Sensor for Amaranth Detection

Amaranth is one of the synthetic azo colorants used to improve the appearance and to increase the appeal of some foods and soft drinks. The excessive consumption of amaranth can be associated with health side effects, emphasizing the need to monitor this food dye. Accordingly, the present study aimed to introduce an electrochemical sensor of glassy carbon electrode (GCE) modified with N-doped reduced graphene oxide (N-rGO), N-rGO/GCE, to detect the amaranth sensitively and rapidly. Several electrochemical techniques such as differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), chronoamperometry (CHA), and cyclic voltammetry (CV) are exploited for the evaluation of the efficiency of the developed electrode for the detection of amaranth. We found that N-rGO/GCE enhanced amaranth oxidation, thus significantly elevating the current signal. Amaranth showed that calibration curves ranged from 0.1 to 600.0 µM, and the limit of detection (LOD) (S/N = 3) was 0.03 μM. Finally, the developed sensor was effectively applied for real samples (tap water, apple juice, and orange juice) with acceptable recovery values from 96.0 to 104.3%.

Application of MnO2 Nanorod–Ionic Liquid Modified Carbon Paste Electrode for the Voltammetric Determination of Sulfanilamide

The current work introduced a convenient single-phase hydrothermal protocol to fabricate MnO₂ nanorods (MnO₂ NRs). Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) and field-emission scanning electron microscopy (FE-SEM) were used to determine the characteristics of MnO₂ NR. Then, ionic liquid (IL) and MnO₂ NRs were utilized to modify a carbon paste electrode (CPE) surface (MnO₂NR-IL/CPE) to voltammetrically sense the sulfanilamide (SAA). An enhanced voltammetric sensitivity was found for the as-developed modified electrode toward SAA when compared with a bare electrode. The optimization experiments were designed to achieve the best analytical behavior of the SAA sensor. Differential pulse voltammetry (DPV) in the optimized circumstances portrayed a linear dependence on various SAA levels (between 0.07 and 100.0 μM), possessing a narrow detection limit (0.01 μM). The ability of the modified electrode to be used in sensor applications was verified in the determination of SAA present in the actual urine and water specimens, with impressive recovery outcomes.

Tandem oxidative amidation of benzylic alcohols by copper(II) supported on metformin-graphitic carbon nitride nanosheets as an efficient catalyst

In this research, an efficient heterogeneous catalyst based on graphitic carbon nitride nanosheets (CN) has been reported. The CN was functionalized by 1,3-dibromopropane as a linker (CN-Pr-Br) and subsequently modified with metformin (CN-Pr-Met). Furthermore, the copper(II) was coordinated on modified CN (CN-Pr-Met-Cu(II)) and during this process, 7.94% copper(II) was loaded into the catalyst structure. The synthesized catalyst was evaluated by various techniques including fourier-transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and inductively coupled plasma atomic emission spectroscopy (ICP-OES). CN-Pr-Met-Cu(II) was used as a catalyst in the synthesis of amides via the oxidation of benzyl alcohols. The conditions of this reaction were optimized in terms of temperature, time, amount of catalyst, type of base, oxidant, and solvent. Moreover, a variety of amides with an efficiency of 75-95% were synthesized. The reaction was carried out in the presence of benzyl alcohols, amine hydrochloride salts, tert-butyl hydroperoxide (TBHP), CaCO3, and CN-Pr-Met-Cu(II) at 80 °C of acetonitrile solvent. The synthesized catalyst can be easily separated from the reaction medium and reused for 7 consecutive runs without a significant reduction in reaction efficiency.

A high-performance electrochemical aptasensor based on graphene-decorated rhodium nanoparticles to detect HER2-ECD oncomarker in liquid biopsy

Evaluation of extracellular domain of human epidermal growth factor receptor-2 (HER2-ECD) oncomarker status is an impressive factor in screening, diagnosing and monitoring early-stage breast cancer (BC). Electrochemical aptamer-based nanobiosensor with high sensitivity and selectivity for quantitative and qualitative measurement of HER2-ECD oncomarker was developed. In this study, the nanocomposite made by distinct materials included reduced graphene oxide nano-sheets (rGONs) and rhodium nanoparticles (Rh-NPs) on the graphite electrode (GE) surface. This structure resulted in amplified electrochemical activity, high surface area, stability, and bio-compatibility. Each of the steps of preparing nanomaterials and setting up biosensor were carefully examined by analytical and electrochemical techniques. Various modified electrodes were constructed and analyzed in terms of electrochemical performance, morphology, size, and shape of nanomaterials. The GE-based aptasensor had a noteworthy and conducive results against HER2-ECD with a wide dynamic range of 10.0-500.0 ng/mL, a low limit of detection (LOD) of 0.667 ng/mL (significantly less than the clinical cut-off), and a low limit of quantification (LOQ) of 2.01 ng/mL. The benefits provided by this aptasensor such as broad dynamic range, high sensitivity, selectivity, stability, reproducibility, and low cost suggest tremendous potential for non-invasive detection and monitoring of the HER2-ECD levels of BC care and clinical diagnosis.