Fabrication of a novel tantalum boride/vanadium carbide modified screen-printed carbon electrode for voltammetric determination of pimonidazole in bio-fluids.

For the first time, a tumour hypoxia marker detection has been developed using two-dimensional layered composite modified electrodes in biological and environmental samples. The concept of TaB2 and V4C3-based MXene composite materials is not reported hitherto using ball-milling and thermal methods and it remains the potentiality of the present work. The successful formation is confirmed through various characterisation techniques like X-ray crystallography, scanning electron microscopy photoelectron, and impedance spectroscopy. A reliable and repeatable electrochemical sensor based on TaB2@V4C3/SPCE was developed for quick and extremely sensitive detection of pimonidazole by various electroanalytical methods. It has been shown that the modified electrode intensifies the reduction peak current and causes a decrease in the potential for reduction, in comparison with the bare electrode. The proposed sensor for pimonidazole reduction has strong electrocatalytic activity and high sensitivity, as demonstrated by the cyclic voltammetry approach. Under the optimal experimental circumstances, differential pulse voltammetry techniques were utilised for generating the wide linear range (0.02 to 928.51 µM) with a detection limit of 0.0072 µM. The resultant data demonstrates that TaB2@V4C3/SPCE nano-sensor exhibits excellent stability, reliability, and repeatability in the determination of pimonidazole. Additionally, the suggested sensor was successfully used to determine the presence of pimonidazole in several real samples, such as human blood serum, urine, water, and drugs.

Electrocatalytic oxidation and amperometric determination of sulfasalazine using bimetal oxide nanoparticles-decorated graphene oxide composite modified glassy carbon electrode at neutral pH.

Cube-shaped samarium orthovanadate (SmVO4) nanoparticles were interconnected with a graphene oxide sheet (GOS) using a simple and eco-friendly method to generate a SmVO4@GOS nanocomposite. SmVO4 was characterized using various spectroscopic and microscopic techniques, which confirmed the wrapping of GOS around the SmVO4 nanoparticles. SmVO4@GOS was then used to modify a glassy carbon electrode (GCE), which was evaluated for its electrochemical performance toward the assay of sulfasalazine (SSZ), an antibiotic drug. Cyclic voltammetry and amperometry were both used for the assay of SSZ using the SmVO4@GOS-modified GCE at pH 7. The modified amperometric sensor is more sensitive, with a low detection limit (2.16 nM) and wide linear range of 20 nM-667 µM (Ag/AgCl). The electrochemical oxidation of SSZ was tested with blood serum and urine samples at physiological pH with recoveries in the range 96.1-98.6%. It indicates that the modified electrochemical sensor has good sensitivity and practical applicability toward SSZ detection. In the field of non-enzymatic sensors, SmVO4@GOS/GCE provides a highly promising performance. Therefore, the electrochemical sensors have capacity for extensive analytical applications in biomedical devices.

Deep eutectic solvent synthesis of iron vanadate-decorated sulfur-doped carbon nanofiber nanocomposite: electrochemical sensing tool for doxorubicin.

Detection of anticancer drug (doxorubicin) using an electrochemical sensor is developed based on a transition metal vanadate's related carbon composite material. With an environmentally friendly process, we have synthesized a metal oxide composite of iron vanadate nanoparticle assembled with sulfur-doped carbon nanofiber (FeV/SCNF). The FeV/SCNF composite was characterized using XRD, TEM, FESEM with elemental mapping, XPS and EDS. In contrast to other electrodes reported in the literature, a much-improved electrochemical efficiency is shown by FeV/SCNF composite modified electrodes. Amperometric technique has been employed at 0.25 V (vs. Ag/AgCl) for the sensitive detection of DOX within a wide range of 20 nM-542.5 µM and it possesses enhanced selectivity in presence of common interferents. The modified electrochemical sensors show high sensitivity of 46.041 µA µM-1 cm-2. The newly developed sensor could be used for the determination of doxorubicin in both blood serum and drug formulations with acceptable results, suggesting its feasibility for real-time applications.

A nanocomposite consisting of cuprous oxide supported on graphitic carbon nitride nanosheets for non-enzymatic electrochemical sensing of 8-hydroxy-2'-deoxyguanosine.

Graphitic carbon nitrides supported cuprous oxide architecture is reported as an efficient electrode material for supercapacitors, especially due to its high charge-transfer conductivity of the electrochemical devices. Herein, we present an electrochemical sensor to specifically detect 8-hydroxy-2'-deoxyguanosine (8-HDG) oxidative stress biomarker using graphitic carbon nitrides that decorate a cuprous oxide cubes modified electrode. The fabricated electrochemical sensor was characterized and proved by electrochemical methods, EDX, FESEM, and amperometry (i-t). In the presence of 8-hydroxy-2'-deoxyguanosine (8-HDG), the effective interaction between graphitic carbon nitrides and 8-HDG favors the accumulation on the Cu2O/g-C3N4/GCE, which increases the electrocatalytic property and amperometric response. The proposed electrochemical sensor exhibits a wide linear range for 8-HDG in 0.1 M phosphate buffer (pH 7.0) from 25 nM to 0.91 mM, and the limit of detection (LOD) is 4.5 nM. The stability of the Cu2O/g-C3N4/GCE is improved when stored at 4 °C. The repeatability and reproducibility of this electrochemical sensor is good and the sensor retains its  current response for 8-HDG detection also after long time storage. The modified sensor proved high selectivity and sensitivity for 8-HDG, which made it possible to determine 8-HDG in biological samples. Furthermore, the Cu2O/g-C3N4/GCE offered a favorable electron transfer between the Cu2O/g-C3N4 and the electrode interface compared to Cu2O/GCE, g-C3N4/GCE, and unmodified GCE. Graphical abstract Electrochemical detection of oxidative stress marker based on Cu2O@g-C3N4 materials modified electrode.

Determination of the antioxidant propyl gallate in meat by using a screen-printed electrode modified with CoSe2 nanoparticles and reduced graphene oxide.

A voltammetric sensor is described for the quantitation of propyl gallate (PG). A screen-printed carbon electrode (SPCE) was modified with reduced graphene sheets that were decorated with cobalt diselenide nanoparticles (CoSe2@rGO). The material was hydrothermally prepared and characterized by several spectroscopic techniques. The modified SPCE displays excellent electrocatalytic ability towards PG. Differential pulse voltammetry, with a peak voltage at 0.34 V (vs. Ag/AgCl) has a sensitivity of 12.84 µA·µM-1·cm-2 and a detection limit as low as 16 nM. The method is reproducible, selective, and practical. This method was applied to the determination of PG in spiked meat samples, and the result showed an adequate recovery. Graphical abstract Schematic of a new method for fast and sensitive electrochemical determination of the food additive propyl gallate in meat.

Optimization of Electrochemical Sensitivity in Anticancer Drug Quantification through ZnS@CNS Nanosheets: Synthesis via Accelerated Sonochemical Methodology.

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.

A sonochemical synthesis of SrTiO3 supported N-doped graphene oxide as a highly efficient electrocatalyst for electrochemical reduction of a chemotherapeutic drug.

A sonochemical based green synthesis method playa powerful role in nanomaterials and composite development. In this work, we developed a perovskite type of strontium titanate via sonochemical process. SrTiO3 particles were incorporated with nitrogen doped graphene oxide through simple ultrasonic irradiation method. The SrTiO3/NGO was characterized by various analytical methods. The nanocomposite of SrTiO3/NGO was modified with laser-induced graphene electrode (LIGE). The SrTiO3/NGO/LIGE was applied for electrochemical sensor towards chemotherapeutic drug detection (nilutamide). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques have been used to examine the electrochemical performance of nilutamide (anti-cancer drug). DPV was found to be more sensitive and found to exhibit a sensitivity 8.627 µA µM-1 cm-2 for SrTiO3/NGO/LIGE with a wide linear range (0.02-892 µM) and low Limit of detection (LOD: 1.16 µM). SrTiO3/NGO/LIGE has been examined for the detection of nilutamide in blood serum and urine samples and obtained a good recovery in the range of 97.2-99.72 %. The enhanced stability and selectivity and practical application results indicates the suitability of SrTiO3/NGO/LIGE towards the detection of nilutamide drug in pharmaceutical industries.

Sonochemical construction of hierarchical strontium doped lanthanum trisulfide electrocatalyst: An efficient electrode for highly sensitive detection of ecological pollutant in food and water.

Herbicides are used constantly in agriculture to enhance productivity across the globe. This herbicide monitoring requires utmost importance since its high dose leads to ecological imbalance and a negative impact on the environment. Moreover, a quantification of toxic herbicide is one of the important problems in the food analysis. In this work, deals with the development of a simple, and facile one-pot sonochemical synthesis of strontium doped La2S3 (Sr@La2S3). Morphological and structural characterization confirms the doping of Sr@La2S3 to generate a hierarchical layered structure. The electrochemical performance of modified with rotating disk electrode (RDE) using Sr@La2S3 composite is high, compared to La2S3 and bare electrodes towards the quantitative detection of mesotrione (MTO) in phosphate buffer. Sr@La2S3/RDE showed good sensitivity for MTO detection and it exhibit a range of 0.01-307.01 µM and limit of detection of 2.4 nM. Besides, the selectivity of fabricated electrode is high as it can electrochemically reduce MTO particularly, even in the presence of other chemicals, biological molecules and inorganic ions. The repeatability of MTO detection is high even after 30 days with a lower RSD values. Hence, simple fabrication of Sr@La2S3/RDE could be a novel electrode for the sensitive, selective, and reproducible determination of herbicides in real-time applications.

Bismuth telluride decorated on graphitic carbon nitrides based binary nanosheets: Its application in electrochemical determination of salbutamol (feed additive) in meat samples.

The design and fabrication of effective electrochemical sensor for ultrasensitive detection of feed additive and multidrug are highly significant in food analysis. In this work, we explored to develop the possibility for rapid detection of feed additive drug using bismuth telluride (Bi2Te3) decorated graphitic carbon nitrides (GCN) nanostructures as a modified electrode for electrochemical sensing. Herein, the modified electrode was focused on the development of electrocatalytic performances for the determination of salbutamol in food products. The electrochemical sensors are developed by bismuth telluride sheets interconnected with graphitic carbon nitrides sheets (Bi2Te3/GCN) on to a screen-printed carbon electrode. The binary nanosheets of Bi2Te3/GCN exhibited an enhanced electrocatalytic ability towards salbutamol detection owing to their selective adsorption, by the combination of electrostatic interaction of binary nanosheets and the formation of charge assisted interactions between salbutamol and Bi2Te3/GCN surfaces. A nanomolar limit of detection (1.36 nM) was calculated in 0.05 M phosphate buffer (PB) supporting electrolyte (pH 7.0) using differential pulse voltammetry. The linear dynamic ranges with respect to salbutamol concentration were 0.01-892.5 µM, and the sensitivity of the sensor was 36.277 µA µM-1 cm-2. The sensor stability and reproducibility performances were observed. However, the obtained results are highly satisfactory which suggest the application of binary nanosheets in real-time food analysis.

Design and Fabrication of Yttrium Ferrite Garnet-Embedded Graphitic Carbon Nitride: A Sensitive Electrocatalyst for Smartphone-Enabled Point-of-Care Pesticide (Mesotrione) Analysis in Food Samples.

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.

A simple sonochemical assisted synthesis of NiMoO4/chitosan nanocomposite for electrochemical sensing of amlodipine in pharmaceutical and serum samples.

In this investigation, a facile sonochemical route has been developed for the preparation of porous nickel molybdate nanosheets/chitosan nanocomposite (NiMoO4/CHIT) by using ammonium molybdate and nickel(II) acetate tetrahydrate and as nickel and molybdate precursor, respectively (ultrasonic power 60 W/cm2 and frequency 20 kHz). The ultrasonic based materials preparation as a fast, convenient and economical approach has been widely used to generate novel nanomaterials. Herein, we report an efficient voltammetric sensor for amlodipine drug by using porous nickel molybdate nanosheets/chitosan nanocomposite (NiMoO4/CHIT). Its structure and properties were characterized by x-ray diffraction pattern, scanning electron microscope, transmission electron microscope, elemental analysis and mapping. The electrochemical studies are indicated the NiMoO4/CHIT modified glassy carbon electrode (GCE) exhibited the good performance towards electrocatalytic sensing of amlodipine drug. Consequently, a linear correlation between the anodic peak current with sensor concentration 0.025-373.6 µM with a detection limit and sensitivity of 4.62 nM and 4.753 µA·µM-1·cm-2, respectively. A voltammetry based drug analysis was found to be high sensitive and reproducible, which able to detect nanomolar concentration. Furthermore, the fabricated electrochemical sensor was applied in drug and biological samples.

Two-dimensional binary nanosheets (Bi2Te3@g-C3N4): Application toward the electrochemical detection of food toxic chemical.

Bismuth telluride is considered as an efficient and super-active electrocatalyst in the sector of electrochemical application. Herein, we prepared binary nanosheets (Bi2Te3) through simple solvothermal and hydrothermal method. Furthermore, to enhance the electrocatalytic activity, graphitic carbon nitrides nanosheets (g-C3N4) were used to prepare the composition of Bi2Te3/g-C3N4 binary nanosheets (BNs) with help of hydrothermal energy. Moreover, Bi2Te3/g-C3N4 hybrid was characterized by various techniques (XRD, XPS, SEM, TEM, EDS and EIS analysis). The electrochemical performance of Bi2Te3/g-C3N4 BNs modified GCEs were analyzed by electrochemical technique (DPV, EIS and CV methods). As modified the Bi2Te3/g-C3N4 BNs modified electrode exhibits excellent electrochemical activity towards food toxic ractopamine (RAC) with high-sensitive and nano-molar detection limit (LOD). Besides, the practical ability was analyzed to detect the RAC in meat samples using Bi2Te3/g-C3N4 BNs modified GCE.

Sonochemical synthesis and fabrication of perovskite type calcium titanate interfacial nanostructure supported on graphene oxide sheets as a highly efficient electrocatalyst for electrochemical detection of chemotherapeutic drug.

In green approaches for electrocatalyst synthesis, sonochemical methods play a powerful role in delivering the abundant surface areas and nano-crystalline properties that are advantageous to electrocatalytic detection. In this article, we proposed the sphere-like and perovskite type of bimetal oxides which are synthesized through an uncomplicated sonochemical procedure. As a yield, the novel calcium titanate (orthorhombic nature) nanoparticles (CaTiO3 NPs) decorated graphene oxide sheets (GOS) were obtained through simple ultrasonic irradiation by a high-intensity ultrasonic probe (Titanium horn; 50 kHz and 60 W). The GOS/CaTiO3 NC were characterized morphologically and chemically through the analytical methods (SEM, XRD, and EDS). Besides, as-prepared nanocomposites were modified on a GCE (glassy carbon electrode) and applied towards electrocatalytic and electrochemical sensing of chemotherapeutic drug flutamide (FD). Notably, FD is a crucial anticancer drug and also a non-steroidal anti-androgen chemical. Mainly, the designed and modified sensor has shown a wide linear range (0.015-1184 µM). A limit of detection was calculated as nanomolar level (5.7 nM) and sensitivity of the electrode is 1.073 µA µM-1 cm-2. The GOS/CaTiO3 modified electrodes have been tested in human blood and urine samples towards anticancer drug detection.

Sonochemical preparation of carbon nanosheets supporting cuprous oxide architecture for high-performance and non-enzymatic electrochemical sensor in biological samples.

Copper (Cu) based metal oxides have high electrocatalytic ability. In this work, we are synthesized stone-like cuprous oxide particles (Cu2O SNPs) covered on acid functionalized graphene oxide (GOS) sheets using ultrasonic process (50 kHz and 100 W). Besides, the chemical structural and crystalline analyses of Cu2O SNPs@GOS composites were characterized by transmission electron microscopy, X-ray crystallography and energy-dispersive X-ray spectroscopy. The Cu2O SNPs@GOS nanomaterials were tested towards detection of 8-hydroxydeoxyguanosine (8-OHdG) in biological samples. As expected Cu2O SNPs@GOS catalyst modified electrodes performed an outstanding catalytic ability on 8-hydroxydeoxyguanosine oxidation. 8-OHdG is oxidative stress biomarker. Further, it is noted that the detection performance of Cu2O SNPs@GOS coated electrodes and it's highly enhanced due to the synergistic effect of Cu2O SNPs and GOS. Besides, the modified materials provide more electro-active faces and as well as rapid electron transport pathway and shorten diffusion. Moreover, oxidation of 8-OHdG sensor is exploring a long linear or working range of 0.02-1465 µM and high sensitivity (8.75 nM). The viability of the Cu2O SNPs@GOS proposed electrochemical methods have tested, to find out 8-OHdG concentrations in biological fluids (blood serum and urine) with a satisfying recovery ranges.

Developing green sonochemical approaches towards the synthesis of highly integrated and interconnected carbon nanofiber decorated with Sm2O3 nanoparticles and their use in the electrochemical detection of toxic 4-nitrophenol.

Highly integrated and interconnected carbon nanofiber hybrid nanofibers decorated with samarium(III) oxide (Sm2O3 NPs) nanoparticles was synthesized by ultrasound assisted method and characterized using X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), energy dispersive x-rays (EDX), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The electrocatalytic activity (ECA) was monitored by detection of toxic 4-nitrophenol under phosphate buffer (pH 7.0). The sonochemical route employed was efficient to prepare Sm2O3 NPs modified electrode and this class of catalysts might be active electrocatalyst for the detection of 4-nitrophenol in drinking water. The screen-printed carbon electrode (SPCE) modified with Sm2O3 NPs@f-CNFs was fabricated in a facile way for the sensitively electrochemical determination of 4-nitrophenol. Under optimized preparation conditions, the electrochemical testing (differential pulse voltammetry) of 4-nitrophenol exhibited a reduction peak at -0.64 V. Compared with bare SPCE, Sm2O3 NPs, f-CNFs, Sm2O3 NPs@f-CNFs modified SPCE showed highest current response. The reduction peaks current vs the concentration of 4-nitrophenol exhibits a linear relation with the concentration range from 0.02 to 387.2 µM and the limit of detection was determined to be M (S/N = 3). In addition, Sm2O3 NPs@f-CNFs was contributed to detecting 4-nitrophenol in drinking water and river water samples with the recover ranging from 95.6% to 98.2%.

Rapid sonochemical synthesis of silver nano-leaves encapsulated on iron pyrite nanocomposite: An excellent catalytic application in the electrochemical detection of herbicide (Acifluorfen).

Herein, we developed a silver nanoparticles decorated iron pyrite flowers (FeS2@Ag NL) based nanocomposite was prepared by a sonochemical method. The formation of FeS2@Ag NL nanocomposite was confirmed by XRD, XPS, HR-TEM and analytical techniques. The FeS2@Ag NL/SPCE was potentially applied towards electrochemical detection of toxic herbicide (acifluorfen-AFF). This provided an efficient sensor platform anchoring FeS2@Ag NL on its surface. Under optimized conditions of differential pulse voltammetric transduction, a linear relationship between the current and the concentration was obtained in the range of 0.05-1126.45 µM for Acifluorfen. The detection limit was observed to be 0.0025 µM. the modified sensor exhibits excellent electrochemical performance, including good linear range, nanomolar detection limit, high sensitivity, and desirable stability. Particularly, the practical applicability was revealed by quantifying the AFF concentration in biological samples.

A relative study on sonochemically synthesized mesoporous WS2 nanorods & hydrothermally synthesized WS2 nanoballs towards electrochemical sensing of psychoactive drug (Clonazepam).

In this paper, mesoporous tungsten sulfide electrocatalyst (MP-WS2) were developed through a facile sonochemical technique (SC) and utilized as an electrocatalyst for the sensitive electrochemical detection of Psychoactive drug. The as-prepared SC-MP-WS2 NRs and HT-WS2 NPs (hydrothermally synthesized) were characterized using XRD, Raman, XPS, FESEM, HRTEM, BET, EDX, and electrochemical analysis, which exposed the formation of WS2 in the form of mesoporous nanorods in shape. Further, the use of the as-developed SC-MP-WS2 NRs and HT-WS2 NPs as an electrocatalyst for the detection of clonazepam (CNP). Interestingly, the SC-MP-WS2 NRs modified screen-printed carbon electrode (SC-MP-WS2 NRs/SPCE) exhibited an excellent electrocatalytic performance, and enhanced reduction peak current when compared to HT-WS2 NPs with unmodified electrode. Moreover, as-prepared SC-MP-WS2 NRs/SPCE displayed wide linear response range (10-551 µM), lower detection limit (2.37 nM) and high sensitivity (24.32 µAµM-1cm-2). Furthermore, SC-MP-WS2 NRs/SPCE showed an excellent selectivity even in the existence of potentially co-interfering compounds. The proposed sensor was successfully applied for the determination of CNP in biological and drug samples with acceptable recovery.

Ultrasound-assisted synthesis of α-MnS (alabandite) nanoparticles decorated reduced graphene oxide hybrids: Enhanced electrocatalyst for electrochemical detection of Parkinson's disease biomarker.

Herein, novel manganese sulfide nanoparticles (MnS NPs) decorated reduced graphene oxide (rGOS) nanocomposite have been designed through a facile ultrasound-assisted method and followed by a sonication process. After then, as-synthesized α-MnS@rGOS was characterized by HRTEM, FESEM, XPS, XRD and EIS. Furthermore, the α-MnS@rGOS nanocomposite modified SPCE (screen-printed carbon electrode) shows excellent electrochemical sensing performance towards Parkinson's disease biomarker of dopamine (DA). Moreover, the fabricated sensor showed a wide linear range for dopamine between 0.02 and 438.6 µM and nanomolar detection limit (3.5 nM). In addition, the α-MnS@rGOS modified SPCE showed selectivity towards the detection of dopamine in presence of a 10-fold higher concentration of other important biomolecules. The nanocomposite film modified SPCE sensor was good stable and reproducible towards the detection of Parkinson's disease biomarker. Furthermore, the as-synthesized α-MnS@rGOS nanocomposite modified SPCE has been applied to the determination of dopamine in human serum, rat serum and pharmaceutical samples with acceptable recoveries.

Facile synthesis of mesoporous WS2 nanorods decorated N-doped RGO network modified electrode as portable electrochemical sensing platform for sensitive detection of toxic antibiotic in biological and pharmaceutical samples.

We report a facile and ultrasound assisted sonochemical synthesis of a Tungsten disulfide nanorods decorated nitrogen-doped reduced graphene oxide based nanocomposite. The WS2 NRs/N-rGOs nanocomposite was characterized by FESEM, HRTEM, XRD, XPS and electrochemical methods and its application towards the electrochemical detection of organo-arsenic drug (coccidiostat). The WS2 NRs/N-rGOs modified SPCE was used for the electrochemical reduction of roxarsone (ROX) and it showed superior electrocatalytic performance in terms of reduction peak current and shift in overpotential when compared to those of WS2 NRs/SPCE, N-rGOs/SPCE and based SPCE. The WS2 NRs/N-rGOs modified SPCE showed an excellent sensing ability towards ROX in nitrogen saturated phosphate buffer (PB) then the other controlled modified and unmodified electrodes. The WS2 NRs/N-rGOs/SPCE displays high sensitive response towards ROX and gives wide linearity in the range of 0.1-442.6 µM ROX in neutral phosphate buffer (pH 7.0) and the sensitivity of the sensor is calculated as 14.733 µA µM-1 cm-2. The WS2 NRs/N-rGOs nanocomposite modified sensor also exhibits valuable ability of anti-interference to electroactive analytes. Furthermore, the as-prepared WS2 NRs/N-rGOs/SPCE has been applied to the determination of ROX in biological and pharmaceutical samples.

Facile synthesis of copper(II) oxide nanospheres covered on functionalized multiwalled carbon nanotubes modified electrode as rapid electrochemical sensing platform for super-sensitive detection of antibiotic.

Herein, we report a super-active electrocatalyst of copper(II) oxide nanoparticles (CuO NPs) decorated functionalized multiwalled carbon nanotubes (CuO NPs@f-MWCNTs) by the ultrasonic method. The as-synthesized CuO NPs@f-MWCNTs was characterized through the FESEM, XPS, XRD and electrochemical impedance spectroscopy (EIS). The combination of highly active CuO NPs and highly conductive f-MWCNTs film with rapid detection enables this nanohybrid to display excellent electrochemical performance towards anesthesia drug. Furthermore, the hybrid electrocatalyst modified SPCE was developed for the determination of flunitrazepam (FTM) for the first time. FTM is important anesthesia drug with high adverse effect in human body. Benefiting from the synergistic reaction of CuO NPs and f-MWCNTs, this nanohybrid exhibited high sensitivity and specificity towards FTM electro-reduction. The CuO NPs@f-MWCNTs film modified SPCE exhibits outstanding electrochemical activity including excellent reproducibility, wide linear range from 0.05 to 346.6 µM with nanomolar limit of detection for FTM detection. Further, the as-modified CuO NPs@f-MWCNTs/SPCE has been applied to determination of FTM in biological and drug samples with satisfactory recovery results, thereby showing a notable potential for extensive (bio) sensor applications.