ABSTRACT
The facile sonochemical synthesis is reported of zinc cobalt oxide (ZnCo2O4) composited with carbon nanofiber (CNF). Structural, chemical, and morphological were characterized by X-ray diffraction (XRD), X-ray photoluminescent spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and transmittance electron microscopy (TEM), respectively. ZnCo2O4/CNF-modified GCE was applied to the detection of bisphenol A (BPA). The modified GCE shows enhanced sensing performance towards BPA, which includes a linear range (0.2 to 120 µM L-1) alongside a low limit of detection (38.2 nM L-1), low interference, and good stability. Detection of lower concentrations of BPA enables real sample analysis in the food industries (milk, orange juice, yogurt, tap water, and baby feeding bottles). Surprisingly, the BPA was detected in milk 510 nM L-1, orange juice 340 nM L-1, yogurt 1050 nM L-1, and tap water 140 nM L-1. Moreover, an interaction mechanism between the BPA analyte and ZnCo2O4 was discussed.
Subject(s)
Benzhydryl Compounds , Carbon , Cobalt , Milk , Nanofibers , Phenols , Benzhydryl Compounds/analysis , Phenols/analysis , Phenols/chemistry , Cobalt/chemistry , Carbon/chemistry , Milk/chemistry , Nanofibers/chemistry , Food Contamination/analysis , Animals , Oxides/chemistry , Limit of Detection , Electrochemical Techniques/methods , Fruit and Vegetable Juices/analysis , Green Chemistry Technology/methods , Yogurt/analysisABSTRACT
Zinc sulfide/graphitic Carbon Nitride binary nanosheets were synthesized by using a novel sonochemical pathway with high electrocatalytic ability. The as- obtained samples were characterized by various analytical methods such as Transmission Electron Microscopy (TEM), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS) to evaluate the properties of ZnS@CNS synthesized by this new route. Subsequently, the electrical and electrochemical performance of the proposed electrodes were characterized by using EIS and CV to establish an electroactive ability of the nanocomposites. The complete properties like structural and physical of ZnS@CNS were analyzed. As-prepared binary nanocomposite was applied towards the detection of anticancer drug (flutamide) by various electrochemical methods such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry. The glassy carbon electrode modified with a ZnS@CNS composite demonstrates a remarkable electrocatalytic efficiency for detecting flutamide in a pH 7.0 (PBS). The composite modified electrode shows synergistic effect of ZnS and CNS catalyst. The electrochemical sensing performance of the linear range was improved significantly due to high electroactive sites and rapid electron transport pathways. Crucially, the electrochemical method was successfully demonstrated in biological fluids which reveals its potential real-time applicability in the analysis of drug.
Subject(s)
Antineoplastic Agents , Electrodes , Graphite , Nitrogen Compounds , Sulfides , Ultrasonic Waves , Zinc Compounds , Zinc Compounds/chemistry , Sulfides/chemistry , Antineoplastic Agents/chemistry , Graphite/chemistry , Flutamide/analysis , Flutamide/chemistry , Electrochemical Techniques/methods , Chemistry Techniques, Synthetic , Electrochemistry , Limit of Detection , Catalysis , Nanocomposites/chemistry , Nanostructures/chemistryABSTRACT
The focus of this paper is laid on synthesizing layered compounds of CuMoO4 and Ti3C2Tx using a simple wet chemical etching method and sonochemical method to enable rapid detection of rutin using an electrochemical sensor. Following structural examinations using XRD, surface morphology analysis using SEM, and chemical composition state analysis using XPS, the obtained CuMoO4/Ti3C2Tx nanocomposite electrocatalyst was confirmed and characterized. By employing cyclic voltammetry and differential pulse voltammetry, the electrochemical properties of rutin on a CuMoO4/Ti3C2Tx modified electrode were examined, including its stability and response to variations in pH, loading, sweep rate, and interference. The CuMoO4/Ti3C2Tx modified electrode demonstrates rapid rutin sensing under optimal conditions and offers a linear range of 1 µΜ to 15 µΜ, thereby improving the minimal detection limit (LOD) to 42.9 nM. According to electrochemical analysis, the CuMoO4/Ti3C2Tx electrode also demonstrated cyclic stability and long-lasting anti-interference capabilities. The CuMoO4/Ti3C2Tx nanocomposite demonstrated acceptable recoveries when used to sense RT in apple and grape samples. In comparison to other interfering sample analytes encountered in the current study, the developed sensor demonstrated high selectivity and anti-interference performance. As a result, our research to design of high-performance electrochemical sensors in the biomedical and therapeutic fields.
Subject(s)
Antioxidants , Nanocomposites , Titanium , Chromatography, Gas , RutinABSTRACT
The rapid fabrication is described of binary electrocatalyst based on a highly porous metal-organic framework with zirconium metal core (Zr-MOF) decorated over the graphitic carbon nitride (g-C3N4) nanosheets via facile ultrasonication method. It is used for the robust determination of antipsychotic drug chlorpromazine (CLP) from environmental samples. The electrochemical behaviour of 2D Zr-MOF@g-C3N4 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The crystalline and porous nature of the composite was characterized by XRD and SEM analysis. The functional groups and surface characteristics were investigated by FT-IR, Raman and XPS. The major electrochemical properties of the Zr-MOF@g-C3N4 composite towards CLP detection were analyzed by CV, chronocoulometric (CC), chronoamperometric (CA) and differential pulse voltammetry (DPV) techniques. The composite exhibits a low detection limit (LOD) of 2.45 nM with a linear range of 0.02 to 2.99 µM and attractive sensitivity for CLP. The sensor system shows higher selectivity towards the possible interferences of CLP drug and exhibits better repeatability and stability. Finally, the fabricated sensor system shows a high recovery range varying from 96.2 to 98.9% towards the real samples. The proposed electrochemical probe might be a promising alternative to the prevailing diagnostic tools for the detection of CLP.
Subject(s)
Antipsychotic Agents , Chlorpromazine , Spectroscopy, Fourier Transform Infrared , Dielectric Spectroscopy , ElectrodesABSTRACT
Carbaryl and carbofuran are the carbamate pesticides which have been widely used worldwide to control insects in crops and house. If the pesticides entered in to the food products and drinking water, they could cause serious health effects in humans. Therefore, the development of a rapid, simple, sensitive and selective analytical device for on-site detection of carbamates is crucial to evaluate food and environmental samples. Recently, semiconducting single-walled carbon nanotube-based field effect transistors (s-SWCNT/FETs) have shown several advantages such as high carrier mobility, good on/off ratio, quasi ballistic electron transport, label-free detection and real-time response. Herein, cobalt ferrite (CFO) nanoparticles decorated s-SWCNTs have been prepared and used to bridge the source and drain electrodes. As-prepared CFO/s-SWCNT/FET had been used for the non-enzymatic detection of carbaryl and carbofuran. When used as a sensing platform, the CFO/s-SWCNT hybrid film exhibited high sensitivity, and selectivity with a wide linear range of detection from 10 to 100 fMand the lowest limit of detections for carbaryl (0.11 fM) and carbofuran (0.07 fM) were estimated. This sensor was also used to detect carbaryl in tomato and cabbage samples, which confirmed its practical acceptance. Such performance may be attributed to the oxidation of carbamates by potent catalytic activity of CFO, which led to the changes in the charge transfer reaction on the s-SWCNTs/FET conduction channel. This work presents a novel CFO/s-SWCNT based sensing system which could be used to quantify pesticide residues in food samples.
Subject(s)
Carbofuran , Nanotubes, Carbon , Pesticides , Humans , Carbaryl , Nanotubes, Carbon/chemistry , CarbamatesABSTRACT
Binder-free and efficient electrochemical sensing of levofloxacin (LF) was successfully developed based on the nitrogen-doped carbon nanodots (NCNDs). The NCNDs were synthesized by hydrothermal carbonation (180°C for 12 h), and the heteroatom was embedded in aqueous solution of ammonia (NH3). Spectral and microscopic characteristization techniques were used to analyze the topological, crystallinity, and chemical binding behavior of synthesized biomass functional material. HR-TEM image revealed a uniform spherical dot (2.96 nm), and superior quantum yield efficiency (0.42 Φ). The NCNDs was drop coated on a glassy carbon electrode (GCE) and electrochemical sensing of LF was performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometric i-t curve in phosphate-buffered saline (PBS; pH = 7.0). The NCNDs modified electrode showed a sharp oxidation peak at +0.95 V (vs. Ag/AgCl) with a four-fold higher current response than the bare GC electrode. The NCNDs/GCE surface not only increases the current response, but has lower detection potential, and facilitates electron transfer reaction. Under optimized working parameters, the NCNDs/GCE showed wide linear concentrations range from 200 nM to 2.8 mM and a low detection limit (LOD) of 48.26 nM (S/N = 3). The electrode modified with NCNDs has high electrochemical sensing stability (RSD = 1.284 ± 0.05% over 5 days), and superior reproducibility (RSD = 1.682 ± 0.06% (n = 3)). Finally, the NCNDs modified GC electrode was successfully applied to quantify the concentration of LF in drug and river water samples with acceptable recovery percentages of 96.60-99.20% and 97.20-99.00% (n=3), respectively.
Subject(s)
Carbon , Levofloxacin , Nitrogen , Reproducibility of Results , Biomass , Pharmaceutical Preparations , WaterABSTRACT
In the present study, we have improvised a biogenic method to fabricate zinc oxide nanoparticles (ZnO NPs) using chitosan and an aqueous extract of the leaves of Elsholtzia blanda. Characterization of the fabricated products was carried out with the help of ultraviolet-visible, Fourier transform infrared, X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and energy-dispersive X-ray analyses. The size of the improvised ZnO NP measured between 20 and 70 nm and had a spherical and hexagonal shape. The ZnO NPs proved to be highly effective in the antidiabetic test as the sample showed the highest percentage of enzyme inhibition at 74% ± 3.7, while in the antioxidant test, 78% was the maximum percentage of 2,2-diphenyl-1-picrylhydrazyl hydrate scavenging activity. The cytotoxic effect was investigated against the human osteosarcoma (MG-63) cell line, and the IC50 value was 62.61 µg/mL. Photocatalytic efficiency was studied by the degradation of Congo red where 91% of dye degradation was observed. From the various analyses, it can be concluded that the as-synthesized NPs may be suitable for various biomedical applications as well as for environmental remediation.
ABSTRACT
Alzheimer's disease (AD) is generally diagnosed using advanced imaging, but recent research suggests early screening using biomarkers in peripheral blood is feasible; among them, plasma tau proteins phosphorylated at threonine 231, threonine 181, and threonine 217 (p-tau217) are potential targets. A recent study indicates that the p-tau217 protein is the most efficacious biomarker. However, a clinical study found a pg/ml threshold for AD screening beyond standard detection methods. A biosensor with high sensitivity and specificity p-tau217 detection has not yet been reported. In this study, we developed a label-free solution-gated field effect transistor (SGFET)-based biosensor featuring a graphene oxide/graphene (GO/G) layered composite. The top layer of bilayer graphene grown using chemical vapor deposition was functionalized with oxidative groups serving as active sites for forming covalent bonds with the biorecognition element (antibodies); the bottom G could act as a transducer to respond to the attachment of the target analytes onto the top GO conjugated with the biorecognition element via π-π interactions between the GO and G layers. With this unique atomically layered G composite, we obtained a good linear electrical response in the Dirac point shift to p-tau217 protein concentrations in the range of 10 fg/ml to 100 pg/ml. The biosensor exhibited a high sensitivity of 18.6 mV/decade with a high linearity of 0.991 in phosphate-buffered saline (PBS); in human serum albumin, it showed approximately 90% of the sensitivity (16.7 mV/decade) in PBS, demonstrating high specificity. High stability of the biosensor was also displayed in this study.
Subject(s)
Alzheimer Disease , Biosensing Techniques , Graphite , Humans , Alzheimer Disease/diagnosis , tau Proteins , Biosensing Techniques/methods , Graphite/chemistry , BiomarkersABSTRACT
Till to date, the application of sulfur-doped graphitic carbon nitride supported transition metal carbide interface for electrochemical sensor fabrication was less explored. In this work, we designed a simple synthesis of molybdenum carbide sphere embedded sulfur doped graphitic carbon nitride (Mo2C/SCN) catalyst for the nanomolar electrochemical sensor application. The synthesized Mo2C/SCN nanocatalyst was systematically characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with elemental mapping. The SEM images show that the porous SCN network adhered uniformly on Mo2C, causing a loss of crystallinity in the diffractogram. The corresponding elemental mapping of Mo2C/SCN shows distinct peaks for carbon (41.47%), nitrogen (32.54%), sulfur (1.37%), and molybdenum (24.62%) with no additional impurity peaks, reflecting the successful synthesis. Later, the glassy carbon electrode (GCE) was modified by Mo2C/SCN nanocatalyst for simultaneous sensing of uric acid (UA) and folic acid (FA). The fabricated Mo2C/SCN/GCE is capable of simultaneous and interference free electrochemical detection of UA and FA in a binary mixture. The limit of detection (LOD) calculated at Mo2C/SCN/GCE for UA and FA was 21.5 nM (0.09 - 47.0 µM) and 14.7 nM (0.09 - 167.25 µM) respectively by differential pulse voltammetric (DPV) technique. The presence of interferons has no significant effect on the sensor's performance, making it suitable for real sample analysis. The present method can be extended to fabricate an electrochemical sensor for various molecules.
Subject(s)
Folic Acid , Uric Acid , Uric Acid/analysis , Electrochemical Techniques/methods , Carbon/chemistry , Electrodes , Limit of Detection , SulfurABSTRACT
Schematic illustration of 2D materials based sensors for the detection of various analytes.
ABSTRACT
A chemiresistive biosensor is described for simple and selective detection of miRNA-21. We developed chemical vapor deposition (CVD) and low-damage plasma treatment (LDPT)-treated bilayer graphene composite of graphene oxide/graphene (GO/GR) for the determination of a reliable biomarker. We have successfully overcome the self-limiting growth mechanism by using CVD method to grow more than one layer of graphene on copper foil. In addition, LDPT can be used to form GO/GR structures for chemiresistive biosensor applications. Due to the direct formation of BLGR (bilayer graphene), the coupling between graphene layers is theoretically superior to that of stacked BLGR, which is also confirmed by the blue shift of the characteristic peak of graphene in Raman spectroscopy. The shift is about double compared with that of stacked BLGR. Based on the results, the limit of detection for the target miRNA-21 was calculated to be 5.20 fM and detection rage is calculated as 100 fM to 10 nM, which is obviously better performance. Compared with previous work, this chemiresistive biosensor has good selectivity, and stability towards detection of miRNA-21. The ability to detect miRNA-21 in different biological fluids was almost identical to that in pH 7.4 phosphate-buffered saline (PBS). Thus, the proposed bilayer GO/GR of modified chemiresistive biosensor may potentially be applied to detect cancer cells in clinical examinations.
Subject(s)
Biosensing Techniques , Graphite , MicroRNAs , Neoplasms , Biomarkers, Tumor , Biosensing Techniques/methods , Gases/chemistry , Graphite/chemistry , Neoplasms/diagnosisABSTRACT
A novel electrochemical method has been developed for determination of nitrite using La-based perovskite-type lanthanum aluminate nanorod-incorporated graphene oxide nanosheets (LaAlO3@GO). Morphological and structural analyses of the prepared perovskite-type electrocatalyst, with and without a glassy carbon electrode (GCE) surface, were performed using various techniques, including transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry, Raman spectroscopy, and electrochemical impedance spectroscopy. Under optimal conditions, the LaAlO3@GO composite-modified GCE (LaAlO3@GO/GCE) exhibited excellent electrocatalytic performance toward the electrooxidation of nitrite (pH = 7.0), with a significant increase in anodic peak currents compared with the bare GCE. Using amperometry, the fabricated sensor exhibited a wide nitrite determination range from 0.01 to 1540.5 µM, with a detection limit of 0.0041 µM. Notably, the proposed LaAlO3@GO/GCE electrode demonstrated a good nitrite detection performance in different meat and water samples. In addition, the LaAlO3@GO/GCE electrode displayed excellent selectivity, repeatability, reproducibility, storage, and operational stability toward nitrite detection.
Subject(s)
Drinking Water , Nitrites , Calcium Compounds , Carbon/chemistry , Drinking Water/analysis , Graphite , Lanthanum , Limit of Detection , Meat/analysis , Nitrites/analysis , Oxides , Plant Extracts , Reproducibility of Results , TitaniumABSTRACT
Glucose is one of the most important monosaccharides found in the food, as a part of more complex structures, which is a primary energy source for the brain and body. Thus, the monitoring of glucose concentration is more important in food and biological samples in order to maintain a healthy lifestyle. Herein, an electrochemical glucose biosensor was fabricated by immobilization of glucose oxidase (GOX) onto poly(3,4-ethylenedioxythiophene):4-sulfocalix [4]arene (PEDOT:SCX)/MXene modified electrode. For this purpose, firstly, PEDOT was synthesized in the presence of SCX (counterion) by the chemical oxidative method. Secondly, MXene (a 2D layered material) was synthesized by using a high-temperature furnace under a nitrogen atmosphere. After that, PEDOT:SCX/MXene (1:1) dispersion was prepared by ultrasonication which was later utilized to prepare PEDOT:SCX/MXene hybrid film. A successful formation of PEDOT:SCX/MXene film was confirmed by HR-SEM, Fourier transform infrared (FT-IR), and Raman spectroscopies. Due to the biocompatibility nature, successful immobilization of GOX was carried out onto chitosan modified PEDOT:SCX/MXene/GCE. Moreover, the electrochemical properties of PEDOT:SCX/MXene/GOX/GCE was studied through cyclic voltammetry and amperometry methods. Interestingly, a stable redox peak of FAD-GOX was observed at a formal potential of -0.435 V on PEDOT:SCX/MXene/GOX/GCE which indicated a direct electron transfer between the enzyme and the electrode surface. PEDOT:SCX/MXene/GOX/GCE also exhibited a linear response against glucose concentrations in the linear range from 0.5 to 8 mM. The effect of pH, sensors reproducibility, and repeatability of the PEDOT:SCX/MXene/GOX/GCE sensor were studied. Finally, this new biosensor was successfully applied to detect glucose in commercial fruit juice sample with satisfactory recovery.
ABSTRACT
In the present research, we aimed to develop a novel electrochemical method based on transition metal tungstate nanorods incorporated sulfur doped carbon nitrides matrix (Ag2WO4@SGCN) for determination of antibiotic drug. The morphological and structural analysis of the prepared Ag2WO4@SGCN were performed by various techniques including SEM, EDS, XRD, and EIS. Under the optimal conditions of the sensor, the Ag2WO4@SGCN modified electrode showed outstanding electrocatalytic performance toward the electro-reduction of nitrofurantoin (NFT) with a significant increase in cathodic peak currents in comparison with the bare electrode. By differential pulse voltammetric (DPV) method the fabricated nitrofurantoin sensor gave linear response in the concentration range from 0.005 to 935 µM with detection limit (3Sb/m) of 0.0013 µM. Importantly, the practically of the proposed Ag2WO4@SGCN modified electrode was demonstrated in different biological samples. In addition, Ag2WO4@SGCN electrode displayed excellent anti-interfering ability and repeatability, reproducibility, storage and operational stability has been successfully demonstrated for detection of NFT.
Subject(s)
Nitrofurans , Silver , Limit of Detection , Nitriles , Reproducibility of Results , Tungsten CompoundsABSTRACT
As the use of pesticides in agriculture is increasing at an alarming rate, food contamination by pesticide residues is becoming a huge global problem. It is essential to develop a sensitive and user-friendly sensor device to quantify trace levels of pesticide and herbicide residues in food samples. Herein, we report an electrocatalyst made up of yttrium iron garnet (Y3Fe5O12; YIG) and graphitic carbon nitride (GCN) to attain picomolar-level detection sensitivity for mesotrione (MTO), which is a widely used herbicide in agriculture. First, YIG was prepared by a hydrothermal route; then, it was loaded on GCN sheets via a calcination method. The surface structures, composition, crystallinity, and interfacial and electrocatalytic properties of the YIG and YIG/GCN were analyzed. As the YIG/GCN displayed better surface and catalytic properties than YIG, YIG/GCN was modified on a screen-printed carbon electrode to fabricate a sensor for MTO. The YIG/GCN-modified electrode displayed a detection limit of 950 pM for MTO. The method was demonstrated in (spiked) fruits and vegetables. Then, the modified electrode was integrated with a miniaturized potentiostat called KAUSTat, which can be operated wirelessly by a smartphone. A first smartphone-based portable sensor was demonstrated for MTO that is suitable for use in nonlaboratory settings.
Subject(s)
Cyclohexanones/analysis , Ferric Compounds/chemistry , Food Contamination/analysis , Graphite/chemistry , Nitrogen Compounds/chemistry , Pesticides/analysis , Point-of-Care Systems , Smartphone , Yttrium/chemistry , Electrochemical Techniques , Microscopy, Electron, Transmission , Reproducibility of Results , Spectroscopy, Fourier Transform Infrared , X-Ray DiffractionABSTRACT
A sensitive voltammetric sensor has been developed for hazardous methyl parathion detection (MP) using graphene oxide@Ce-doped TiO2 nanoparticle (GO@Ce-doped TiO2 NP) electrocatalyst. The GO@Ce-doped TiO2 NPs were prepared through the sol-gel method and characterized by various physicochemical and electrochemical techniques. The GO@Ce-doped TiO2 NP-modified glassy carbon electrode (GCE) addresses excellent electrocatalytic activity towards MP detection for environmental safety and protection. The developed strategy of GO@Ce-doped TiO2 NPs at GCE surfaces for MP detection achieved excellent sensitivity (2.359 µA µM-1 cm-2) and a low detection limit (LOD) 0.0016 µM with a wide linear range (0.002 to 48.327 µM). Moreover, the fabricated sensor shows high selectivity and long-term stability towards MP detection; this significant electrode further paves the way for real-time monitoring of environmental quantitative samples with satisfying recoveries.
Subject(s)
Electrochemical Techniques/methods , Graphite/chemistry , Methyl Parathion/analysis , Nanocomposites/chemistry , Carbon/chemistry , Catalysis , Cerium/chemistry , Electrodes , Insecticides/analysis , Limit of Detection , Metal Nanoparticles/chemistry , Reproducibility of Results , Titanium/chemistryABSTRACT
The current work reports the photocatalytic and antibacterial performance of tin (Sn) doped zinc oxide (ZnO) nanoparticles synthesized via ultrasonic aided co-precipitation technique. The increase of Sn concentration decreased the lattice parameter and increased the crystallite size without changing the ZnO structure. The hexagonal shaped particles and sheets obtained for 3% and 5% Sn substituted ZnO, respectively. The increase of dopant concentration reduced the reflectance and optical band gap energy of Sn doped ZnO. The vibrational band present at 1443 cm-1 confirmed the successful bond formation of Sn-O-Zn. The 5% Sn doped ZnO nanoparticles exhibited greater dye elimination rate of methylene blue compared to 3% Sn. The antibacterial activity of Sn doped ZnO showed the higher zone of inhibition about 14 mm against different pathogens. The 5% Sn doped ZnO photocatalyst improve the transfer rate of photo excite carrier and decrease the rate of recombination which greatly influence on the photocatalytic and antibacterial performance.
Subject(s)
Nanoparticles , Zinc Oxide , Anti-Bacterial Agents/pharmacology , Methylene BlueABSTRACT
In this study, 2D/2D/2D heterostructured r-GO/LTH/ZnO/g-C3N4 nanohybrid were synthesized through hydrothermal method. The strong electrostatic interaction between the negatively charged g-C3N4 and r-GO nanosheets with positively charged layered triple hydroxide (LTH) nanosheets are effectively influences the successful formation of heterojunction. The LTH nanosheets are well spread on the g-C3N4 nanosheets combined with r-GO. In particular, the as prepared heterojunction shows a better photocatalytic degradation activity compared to pristine samples and the significant enhancement in the photocatalytic performance is mainly accredited to the large interfacial charge transition of photogenerated charge carriers under the visible light irradiation. Although the 2D/2D/2D heterojunction effectively hinders the charge carrier recombination resulting high photocatalytic activity with good stability. In addition, the r-GO supported LTH/ZnO/g-C3N4 heterojunction shows high photo-stability after sequential experimental runs with no obvious change in the dye degradation process. Consequently, the role of active species was investigated over the r-GO/LTH/ZnO/g-C3N4 heterojunction with the help of different scavengers.
Subject(s)
Zinc Oxide , Catalysis , Graphite , Hydroxides , LightABSTRACT
An electrocatalyst modified electrode has been investigated to develop the rapid detection of antibiotics. The modified electrocatalyst was intended for the determination of sulfadiazine (SFZ) in biological fluids by electrochemical methods. Nanocube of zinc manganite (ZnMn2O4-NC) is prepared by hydrothermal method and a glassy carbon electrode (GCE) has been modified with the zinc manganite. The ZnMn2O4/GCE exhibit enhanced detection performances towards SFZ drug owing to their selective adsorption ability and the combination of electrostatic attraction of nanocube with SFZ. The modified electrocatalyst shows excellent electrocatalytic interactions with antibiotic drug. Besides, the modified sensors exhibit nanomolar detection limit (0.0021 µM) in 0.05 M phosphate buffer (pH = 7.0) using differential pulse voltammetric method. The working range of the modified electrode is 0.008-1264 µM, and the sensitivity of the SFZ sensor is 11.44 µA µM-1 cm-2. The modified sensor stability and reproducibility performances have been examined by electrochemical method. In addition, the obtained results of real sample analysis with different concentrations of SFZ in biological fluids are satisfactory with good recovery.