Electrochemical Sensor For Simultaneous Determination Research Articles

Rapid, simple, and simultaneous electrochemical determination of cadmium, copper, and lead in Baijiu using a novel covalent organic framework based nanocomposite.

It is of great significance to develop a simple and rapid electrochemical sensor for simultaneous determination of heavy metal ions (HMIs) in Baijiu by using new nanomaterials. Here, graphene (GR) was utilized to combine with covalent organic frameworks (COFs) that was synthesized via the aldehyde-amine condensation between 2, 5-dimethoxyterephthalaldehyde (DMTP) and 1, 3, 5-tris(4-aminophenyl) benzene (TAPB) to prepare a new GR/COFDPTB/GCE sensor for electrochemical sensing multiple HMIs. Compared with the glass carbon electrode (GCE), GR/GCE and COFDPTB/GCE, the developed sensor exhibited excellent electrochemical analysis ability for the simultaneous detection of Cd2+, Pb2+, and Cu2+ owing to the synergistically increased the specific surface area, the periodic porous network and plenty of effective binding sites, as well as the enhanced conductivity. Under the optimized experimental parameters, the proposed sensor showed good linearity range of 0.1-25μM for Cd2+, and both 0.1-11μM for Pb2+ and Cu2+ with the detection limits of Cd2+, Pb2+, and Cu2+ being 0.011μM, 8.747nM, and 6.373nM, respectively. Besides, the designed sensor was successfully applied to the simultaneous detection of the three HMIs in Baijiu samples, suggesting its good practical application performance and a new method for the rapid detection of HMIs being expended.

Flexible electrochemical sensor for simultaneous determination of levodopa and uric acid based on carbon nanotube fibers

Levodopa (L-Dopa) is a widely prescribed drug for treating Parkinson's disease (PD), however, due to its motor complications, dosage management is required during clinical treatment. Uric acid (UA) is an important antioxidant in the body and is believed to have a defensive effect on the development and progression of PD. Therefore, accurate measurement of L-Dopa and UA in PD patients is of great significance. In this study, a flexible electrochemical sensor based on carbon nanotube (CNT) fibers was developed for individual and simultaneous determination of L-Dopa and UA. The electrochemical behavior and detection performance of the sensor were studied by cyclic voltammetry and differential pulse voltammetry. The CNT fibers (CNTF) electrode exhibited a wide detection range of 0.16–2.08 mM and 0.08–0.96 mM for L-Dopa and UA, as well as a high sensitivity of 0.7142 μA μM−1 cm−2 and 1.33 μA μM−1 cm−2, respectively. In addition, the sensor also exhibited good anti-interference, repeatability and bending stability, and has been successfully applied to the detection of L-Dopa and UA in bovine serum samples.

Ruthenium nanoparticles encrusted with nitrogen & sulphur magnetic quantum dots as an efficient electrochemical sensor for simultaneous determination of itraconazole and terbinafine; a dual regimen for black fungus: Magnetic solid phase micro-extraction for urine and plasma analysis

After COVID-19 pandemic, Mucormycosis (black fungus) spreads as one of its related complications, due to the decrease in immunity system after administration of COVID-19 treatment drugs. A combination therapy of Itraconazole (ITR) and Terbinafine (TEB) was proved to be effective for treatment of black fungus. A novel electrochemical sensor was designed for estimation of ITR & TEB simultaneously by square wave voltammetric (SWV) technique. The sensor was fabricated using N&S-codoped magnetic quantum dots (N,S-MQDs) and ruthenium nanoparticles (Ru NPs). The fabricated sensor was characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), powder X ray diffraction (pXRD), Fourier transform-Infrared (FT-IR), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). Full optimization study for various experimental and instrumental parameters, in addition to method validation following International conference on Harmonization (ICH) guidelines was achieved. A good linearity in the range of 0.5–30 μg mL−1 with limit of detection (LOD) 0.24 and 0.19 μg mL−1 for ITR and TEB, respectively were obtained. The sensor was applied for analysis of ITR and TEB simultaneously in human plasma and urine samples without any interferences by applying dispersive magnetic solid phase micro-extraction (dMSPE) technique, where excellent recovery results exceeding 95 % were achieved.

Electrochemical sensor for simultaneous determination of antiviral favipiravir drug, paracetamol and vitamin C based on host–guest inclusion complex of β-CD/CNTs nanocomposite

Favipiravir (FVI) is extensively used as an effective medication against several diverse infectious RNA viruses. It is widely administered as an anti-influenza drug. Combination therapy formed from FVI, paracetamol (PAR) and vitamin C (VC) is needed for treating patients diseased by RNA viruses. Thus, an efficient electrochemical sensor is developed for detecting FVI in human serum samples. The sensor is fabricated by casting a thin layer of carbon nanotubes (CNTs) over a glassy carbon (GC) electrode surface followed by electrodeposition of another layer of β-cyclodextrin (β-CD). Under optimized conditions, the sensor shows excellent catalytic effect for FVI, PAR and VC oxidation in the concentration ranges (0.08 µM → 80 µM), (0.08 µM → 50 µM) and (0.8 µM → 80 µM) with low detection limits of 0.011 μM, 0.042 μM and 0.21 μM, respectively. The combined effect of host–guest interaction ability of β-CD for the drugs, and a large conductive surface area of CNTs improves the sensing performance of the electrode. The sensor exhibits stable response over 4 weeks, good reproducibility, and insignificant interference from common species present in serum samples. The reliability of using the sensor in serum samples shows good recovery of FVI, PAR and VC.

A covalent organic frameworks@gold nanoparticles@graphene nanocomposite based electrochemical sensor for simultaneous determination of trace Cd2+, Pb2+ and Cu2+

It's very exciting to develop an electrochemical sensor for simple, rapid and simultaneous determination of heavy metal ions in Baijiu by applying new nanocomposites. Herein, a novel COFDPTB@gold nanoparticles (AuNPs)@graphene (GR) was obtained via combining COFDPTB synthesized using the Schiff-base condensation between 2, 5-dimethoxyterephthalaldehyde and 1, 3, 5-tris(4-aminophenyl) benzene with AuNPs and GR. Owing to the high porosity and abundant adsorption sites of COFDPTB, the outstanding electrical conductivity of AuNPs and GR, as well as the high specific area and synergy of COFDPTB, AuNPs and GR, the proposed sensor exhibited excellent analysis performance for the detection of Cd2+, Pb2+ and Cu2+. Under optimized conditions, the sensor showed good linearity range of 0.5–18 μM for Cd2+, and both 0.5–6.0 μM for Pb2+ and Cu2+ with the detection limits of 3.025 nM, 5.849 nM and 9.993 nM, respectively. In addition, the recovery measurement suggested the practicality of the prepared sensor.

Eco-friendly synthesized silver-magnetic nanocomposite supported on nanocellulose modified glassy carbon electrode as an electrochemical sensor for simultaneous determination of dopamine and acetaminophen

Herein, a novel and eco-friendly synthesis of electrochemical sensor for simultaneous determination of dopamine (DA) and acetaminophen (AC) based on silver-magnetic nanocomposite supported on nanocellulose modified glassy carbon electrode (Ag-Fe3O4/NC/GCE). The synthesized nanomaterials have been characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDX). Important parameters such as scan rate and pH effects were studied to achieve the ideal conditions. The linearity ranges and the detection limits of DA and AC were 0.01–10.0 μM, 0.05–15.0 μM, 6.0 and 8.0 nM, respectively. The developed sensor was applied to real samples for the simultaneous determination of DA and AC.

Optimization of voltammetric parameters for sensitive and simultaneous determination of ferulic acid and vanillin using a glassy carbon electrode based on 2-aminonicotinic acid in the presence of surfactant media

The electrochemical sensor for simultaneous determination of ferulic acid (FA) and vanillin (VA) was prepared by electrochemical deposition of 2-aminonicotinic acid (2-ANA) on the glassy carbon (GC) electrode. The voltammetric determination of FA and VA was performed in the BR buffer solution in the presence of sodium dodecyl sulfate as a surfactant with SWV. The parameters of the SWV technique were optimized by response surface methodology experimental design. Under optimized conditions, the 2-ANA/GC modified electrode presented a linear working range of 2.8 × 10−8 M to 7.50 × 10−6 M and 7.50 × 10−6 M to 2.45 × 10−5 M for FA, 3.06 × 10−8 M to 1.27 × 10−5M for VA. The detection limit (LOD) values for FA and VA were 6.87 nM and 9.23 nM, respectively. Using the 2-ANA/GC sensor, concentrations of FA and VA in instant coffee and milk samples were determined with %recovery values between 103.40 and 97.07 and %RSD values between 0.76 and 4.40.

Highly sensitive and selective electrochemical sensor for simultaneous determination of gallic acid, theophylline and caffeine using poly(l-proline) decorated carbon nanotubes in biological and food samples

In this work, a novel, simple and reproducible poly(l-proline)/functionalized multi-walled carbon nanotube composite on glassy carbon electrode (poly(PRO)-MWCNTs/GCE) was developed as an electrochemical sensor for the simultaneous determination of gallic acid (GA), theophylline (TP) and caffeine (CAF) by differential pulse voltammetry (DPV).The sensing platform was optimized by experimental design and response surface methodology, using various factors affecting polymerization and detection, such as electropolymerization time and potential, and pH, respectively. As a result, the dispersion conditions were the mixing of 1.78 mg MWCNTs with 1.00 mL l-proline solution to 4.14 mg mL−1 (in SDBS 0.5%), followed by 21 min of sonication with electropolymerization by 16 cyclic scans. In addition, the final analysis was performed at a pH of 3.00 and prior accumulation at 0.350 V for 40 s.The electrochemical behavior of GA, TP and CAF on the optimized sensor was investigated. As a result, the electrode preserves and synergistically combines the properties of each modifier. This new electrochemical sensor showed superior electrocatalytic properties for the oxidation of GA, TP and CAF, which significantly improved the sensitivity of the three compounds.Under the optimized experimental conditions, the detection limits achieved by S/N were 0.03, 0.04 and 0.11 μmol L−1 for GA, TP and CAF, respectively. The analysis of real samples was successfully performed in human breast milk, tea, infusion of yerba mate, coffee, Coca-Cola zero and energy drink, showing good recoveries, ranged between 87 and 108%. The proposed sensor also showed good selectivity, repeatability and reproducibility, indicating feasibility and reliability.This is the first time that the l-proline monomer is used as a dispersant for MWCNTs and as a precursor for the in-situ polymerization of the proline polymer. Previously, the electropolymerizations were carried out with the monomer in solution rather than as an exfoliant of MWCNTs, where the polymer is electrosynthesized between MWCNTs rather than on them. In this way, the large specific surface area and strong adsorption ability of the nanomaterial are enhanced, and the ability to promote electron transfer reaction is increased, which provides enough effective reaction sites.

Ultra-sensitive electrochemical sensors for simultaneous determination of dopamine and serotonin based on titanium oxide-gold nanoparticles-poly Nile blue (in deep eutectic solvent)

Determining blood serum levels of dopamine (DA) and serotonin (SE), which are important neurotransmitters, is of great importance in diagnosing and treating many diseases. In this work, a new disposable sensor was developed for the simultaneous determination of DA and SE. First, titanium oxide nanoparticles (TiO2NP) were modified on the screen-printed carbon electrodes (SPCE) by physical adsorption. Then, AuNP was coated on SPCE/TiO2NP by cyclic voltammetry (CV). Finally, a deep eutectic solvent (DES) appropriate for green chemistry, ethylene glycol/choline chloride, was used to electro-polymerize Nile blue (NB) on SPCE/TiO2NP/AuNP. The materials of TiO2NP, AuNP, and PNBDES were characterized by FE-SEM-EDX, XRD, and FTIR. The effects of TiO2NP, AuNP, and PNBDES modification order on the electrode surface on the separation of differential pulse voltammetry (DPV) peaks of DA and SE were investigated. DPV analysis conditions (deposition time and potential) and pH effect were examined. Analytical parameters of the prepared sensor were determined for both individual and simultaneous determination of DA and SE. The detection limits (3 σ/m) for simultaneous detection are 1.39 nM and 2.47 nM for DA and SE, respectively. The sensor's repeatability, reproducibility, and reusability were examined for the simultaneous determination of DA and SE. Application stability of the developed sensor was determined as 20 days and storage stability as 4 weeks. The selectivity of the DA and SE sensor in the presence of ascorbic acid, uric acid, glucose, and citric acid was investigated, and it was observed that the selectivity of the sensor was satisfactory. The disposable sensor simultaneously determined DA and SE in blood serum samples, and high recoveries were acquired. A new disposable sensor with great repeatability and reproducibility was created for the quick, practical, selective, and simultaneous analysis of DA and SE at low concentrations.

Electrochemical sensor for simultaneous determination of paracetamol, propyphenazone, and caffeine – Electrodes based on poly(L-cystine)/gold nanoparticles plating on pencil graphite

An electrode based on pencil leads (PGE) coated with gold nanoparticles (AuNPs) and poly(L-cystine) (P(L-cyst)) was devised and used for the simultaneous analysis of ternary drug combinations, namely, paracetamol (PA), propyphenazone (PRO) and caffeine (CA). The sensor is designed step-by-step by electro-polymerization: P(L-cyst) plating on the surface of PGE and then electrodeposition of AuNPs. The electrode performance was investigated using cyclic voltammetry (CV). Changes on the electrode surface were elucidated by electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FE-SEM), and Energy Dispersive X-ray analysis (EDX). Compared to bare PGE, the modified sensor proved to be better in electrochemical current density for the analytes. The improvement was attributed to the synergistic effects of AuNPs and the organic matrix. The linear ranges were 0.023–90.0 µM (for PA), 0.009 – 30.0 µM (for PRO), and 0.454–600.0 µM (for CA). Trial studies were also done on real samples to reveal the accuracy and reproducibility of the method.

Development of an electrochemical sensor for simultaneous determination of glucose and insulin: Application for accurate classification of diabetes mellitus

Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels, resulting from defects in insulin secretion, insulin action, or both. Accurate and sensitive detection of glucose and insulin concentrations is crucial for the effective management and diagnosis of diabetes. Current techniques for glucose and insulin detection, such as enzyme-linked immunosorbent assay (ELISA) and glucose oxidase-based methods, have limitations including complex procedures, high costs, and insufficient selectivity. In this paper, we report the development of a coupled electrochemical sensor for the simultaneous detection of glucose and insulin concentrations, enabling classification of diabetes mellitus. The sensor is based on a modified electrode, NC-A/GCE, which demonstrates high sensitivity and selectivity towards both analytes. We utilize differential pulse voltammetry (DPV) and chronoamperometry techniques for quantitative analysis and demonstrate the sensor's potential for accurate diabetes classification through a large dataset of detection data.

Bismuth Metal–Organic Framework/Carbon Nanosphere Composites for Ultrasensitive Simultaneous Electrochemical Detection of Lead and Cadmium

An amino-functionalized bismuth metal–organic framework (Bi-BDC-NH2) composited with nitrogen-doped mesoporous carbon nanosphere (NMCS) was prepared to fabricate a Bi-BDC-NH2@NMCS electrochemical sensor for simultaneous determination of Pb(II) and Cd(II). The synthesized Bi-BDC-NH2 was granular, amorphous, and loosely aggregated to form a porous structural composition where NMCS was embedded. The large specific area and exposed sites of Bi-BDC-NH2@NMCS copromote the adsorption and electron transfer of metal ions on the electrode surface. Compared with the traditional bismuth film electrode, the Bi-BDC-NH2@NMCS electrode can improve the charge transfer, stability, and conductivity. The developed method exhibited superior stripping performance with a detection limit of 0.36 ng mL–1 for Pb(II) and 0.44 ng mL–1 for Cd(II), respectively, and a linear range of 1.0–1500 ng mL–1. It was applied to detect Pb(II) and Cd(II) in liver, fish, and shrimp samples with recoveries of 93.6–99.7% and 94.4–103.2%, respectively.

A flexible electrochemical sensor for simultaneous determination of glucose (Glu) and ethanol (Eth) using ZnO and Pd nanoparticles

A flexible electrochemical sensor for simultaneous determination of glucose (Glu) and ethanol (Eth) using ZnO and Pd nanoparticles

Graphene Oxide-PAMAM Nanocomposite and Ionic Liquid Modified Carbon Paste Electrode: An Efficient Electrochemical Sensor for Simultaneous Determination of Catechol and Resorcinol.

In this paper, a simple strategy was proposed for the analysis of catechol by a carbon paste electrode (CPE) modified with graphene oxide-third generation of poly(amidoamine) dendrimer (GO/G3-PAMAM) nanocomposite and ionic liquid (IL). The synthesis of GO-PAMAM nanocomposite was confirmed using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared spectroscopy (FT-IR) techniques. The prepared modified electrode (GO-PAMAM/ILCPE) exhibited good performance to detect catechol with a notable decrease in overpotential and increase in current compared with an unmodified CPE. Under optimum experimental conditions, GO-PAMAM/ILCPE electrochemical sensors indicated a lower limit of detection (LOD) of 0.034 μM and a linear response in the concentration range of 0.1 to 200.0 µM for the quantitative measurement of catechol in aqueous solutions. In addition, GO-PAMAM/ILCPE sensor exhibited an ability to simultaneously determine catechol and resorcinol. It can be found that catechol and resorcinol could be completely separated on the GO-PAMAM/ILCPE with the differential pulse voltammetry (DPV) technique. Finally, a GO-PAMAM/ILCPE sensor was utilized to detect catechol and resorcinol in water samples with recoveries of 96.2% to 103.3% and relative standard deviations (RSDs) of less than 1.7%.

A highly sensitive and ecofriendly assay platform for the simultaneous electrochemical determination of rifampicin and isoniazid in human serum and pharmaceutical formulations

Simple fabrication of an electrochemical sensor for simultaneous determination of rifampicin and isoniazid based on electrochemical modification of SPCE surface with reduced graphene oxide and nickel hydroxide film (Ni(OH)2/rGO/SPCE) without using toxic chemical agents.

Electrochemical sensor for simultaneous determination of trifluoperazine and dopamine in human serum based on graphene oxide-carbon nanotubes/iron-nickel nanoparticles.

Trifluoperazine (TFLP) is an important psychiatric medication that balances the dopamine (DA) level in the brain for patients suffering from neurological disorder diseases. An efficient electrochemical sensor is developed for detecting TFLP in real human serum samples. The sensor is fabricated by casting the GC surface with two consecutive thin layers, namely a graphene oxide-carbon nanotubes mixture (GRO-CNT), and iron-nickel nanoparticles (Fe-Ni). The diffusion-controlled oxidation process of TFLP at the composite surface includes one electron transfer process. Under optimized conditions, the sensor in human serum shows excellent catalytic effect for simultaneous determination of TFLP and dopamine (DA) in the same concentration range (0.5 μM to 18 μM) with low detection limits of 0.13 μM and 0.32 μM respectively. The combined effect of a large conductive surface area and the excellent catalytic activity of the nanocomposite improves the sensor's performance. The sensor exhibits a stable current response over four weeks, excellent reproducibility, and insignificant interference from common species present in human serum samples. The reliability test of using the sensor in serum samples shows good recovery of TFLP.

Dual-template imprinted polymer electrochemical sensor for simultaneous determination of malathion and carbendazim using graphene quantum dots.

Malathion (MAL) and carbendazim (CBZ) are organophosphate pesticides and fungicides, respectively. They are often used simultaneously in agriculture, and both have been shown to have harmful effects on humans and animals. Therefore, it is important to be able to measure both of these toxins simultaneously in order to assess their potential risks. This study aims to design a dual template electrochemical sensor using a cost-effective graphite-epoxy composite electrode (GECE) modified with molecularly imprinted polymers (MIPs) coated on graphene quantum dots (GQDs) for simultaneous detection of MAL and CBZ in real samples. GQDs were synthesized initially, and their surface was coated with MIPs that were formed using MAL and CBZ as the template molecules, ethylene glycol dimethyl acrylate as the cross-linker, and methacrylic acid as the functional monomer. The GQDs@MIP were characterized using Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and X-ray scattering spectroscopy. Parameters affecting the sensor response, such as the percentage of GQDs@MIP in the fabricated electrode, the pH of the rebinding solution and analysis solution, and the incubation time, were optimized. The optimum pH values of the rebinding solution were verified using density functional theory (DFT) calculations. Under the optimized conditions, differential pulse voltammetry (DPV) response calibration curves of MAL and CBZ were generated, and the results showed that the sensor had a linear response to MAL in the range of 0.02-55.00 μM with a limit of detection (LOD) of 2 nM (S/N = 3) and to CBZ in the range of 0.02-45.00 μM with a low LOD of 1 nM (S/N = 3). The results also demonstrated the proposed sensor's long-term stability and anti-interference capability. The practical applicability of the fabricated electrode was evaluated for real sample analysis, and good recovery values were obtained.

PdNPs/carbon dots/silica hybrid nanostructures: the development of an electrochemical sensor for simultaneous determination of dopamine and serotonin in real samples

PdNPs/carbon dots/silica hybrid nanostructures: the development of an electrochemical sensor for simultaneous determination of dopamine and serotonin in real samples

Fabrication of niobium metal organic frameworks anchored carbon nanofiber hybrid film for simultaneous detection of xanthine, hypoxanthine and uric acid

Early determination of abnormal levels of uric acid (UA), xanthine (XA), and hypoxanthine (HXA) in the body fluid and food stuff could be useful in preventing various diseases. In this paper, we have fabricated a self-standing hybrid film based on niobium (benzene 1,3,5-tricarboxylic acid) MOFs (Nb(BTC)MOFs) and carbon nanofibers (CNFs) and explored as an enzyme-free electrochemical sensor for simultaneous determination of these analytes in phosphate buffer (pH = 7). As-developed hybrid film has a high specific surface area that permits faster transport of analyte molecules across the electrode-electrolyte interfaces, whereas a large number of active oxygen functionalities in MOF matrix could promote the sensitivity of the hybrid sensor. The Nb(BTC)MOF@CNF modified glassy carbon electrode (GCE) sensor demonstrated excellent electrochemical responses to these purine derivatives. The diffusion-controlled electrooxidation reactions of these three analytes were noticed. The hybrid sensor exhibited a wide linear range of 5 to 2000 µM along with a low LOD of 70 nM, 76 nM, and 68 nM for UA, XA, and HXA, respectively. The present interference-free sensor showed high selectivity and good storage stability (40 days). Finally, the sensing performances of the Nb(BTC)MOF@CNF/GCE toward UA, XA, and HXA in real samples were found to comparable to those of high-performance liquid chromatography (HPLC) results.

Electrochemical Sensor Based on Multi-Walled Carbon Nanotubes and N-Doped TiO2 Nanoparticles for Voltametric Simultaneous Determination of Benserazide and Levodopa

An electrochemical sensor for simultaneous determination of Benserazide (BEZ) and levodopa (L-dopa) was successfully developed using a glassy carbon electrode (GCE) modified with multi-walled carbon nanotube and nitrogen-doped titanium dioxide nanoparticles (GCE/MWCNT/N-TiO2). Cyclic voltammetry and square wave voltammetry were employed to investigate the electrochemical behavior of different working electrodes and analytes. In comparison with unmodified GCE, the modified electrode exhibited better electrocatalytic activity towards BEZ and L-dopa and was efficient in providing a satisfactory separation for oxidation peaks, with a potential difference of 140 mV clearly allows the simultaneous determination of these compounds. Under the optimized conditions, linear ranges of 2.0-20.0 and 2.0-70.0 μmol L-1 were obtained for BEZ and L-dopa, respectively, with a limit of detection of 1.6 µmol L-1 for BEZ and 2.0 µmol L-1 for L-dopa. The method was applied in simultaneous determination of the analytes in pharmaceutical samples, and the accuracy was attested by comparison with HPLC-DAD as the reference method, with a relative error lower than 4.0%.