Fabrication of hierarchical NiCo2S4@CoS2 nanostructures on highly conductive flexible carbon cloth substrate as a hybrid electrode material for supercapacitors with enhanced electrochemical performance

A feasible sonochemical approach to synthesize CuO@CeO2 nanomaterial and their enhanced non-enzymatic sensor performance towards neurotransmitter

A nanostructured and high conductive cupric oxide (CuO NPs) with hierarchical CeO₂ sheets-like structure was synthesized by a facile sonochemical approach. Furthermore, CuO/CeO₂ nanostructure is synthesized by high-intensity ultrasonic probe (Ti-horn, 50 kHz and 100 W) at ambient air. Moreover, the synthesized CuO/CeO₂ material was characterized by various analytical techniques including FESEM, EDX, XRD and electrochemical methods. Then, the synthesized CuO/CeO₂ composite was applied for the electrocatalytic detection of dopamine using CV and DPV techniques. In addition, the CuO/CeO₂ modified electrode has good electrocatalytic performance with high linear range from 0.025 to 98.5 µM towards the determination of dopamine drug and high sensitivity of the CuO/CeO₂ modified drug sensor was calculated as 16.34 nM and 4.823 μA·µM^-1·cm^-2, respectively. Moreover, a repeatability, reproducibility and stability of the CuO@CeO₂ mixture modified electrode were analyzed towards the determination of dopamine biomolecule. Interestingly, the real time application of CuO@CeO₂ modified electrode was established in different serum and drug samples.

Facile sonochemical synthesis of rutile-type titanium dioxide microspheres decorated graphene oxide composite for efficient electrochemical sensor

In this reports the facile and green synthesis of rutile-type titanium dioxide nanoparticles decorated graphene oxide nanocomposite via the ultrasonication process (frequency: 50 kHz, Power: 100 W/cm² and Ultrasonic type: Ti-horn). Because, the sonochemical synthesis method is simple, non-explosive and harmless method than other conventional technique. Furthermore, the synthesized material was characterized by various analytical techniques including FESEM, EDX, XRD, EIS and electrochemical methods. Then, the synthesized TiO₂ MPs@GOS composite was applied for the electrocatalytic detection of theophylline (TPL) using CV and amperometric (current-time) techniques. Captivatingly, the modified sensor has excellent electrocatalytic performance with the wider linear range from 0.02 to 209.6 µM towards the determination of theophylline and the LOD and sensitivity of the modified sensor was calculated as 13.26 nM and 1.183 μA·µM^-1·cm^-2, respectively. In addition, a selectivity, reproducibility and stability of the TiO₂ MPs@GOS modified GCE were analyzed towards the determination of theophylline molecule. Finally, the real time application of TiO₂ MPs@GOS modified theophylline sensor was established in serum and drug samples.

Sonochemical synthesis and fabrication of honeycomb like zirconium dioxide with chitosan modified electrode for sensitive electrochemical determination of anti-tuberculosis (TB) drug

Herein, novel honeycomb like zirconium dioxide with chitosan (ZrO₂@chitosan) nanocomposite have been designed through a facile ultrasound-assisted method and followed by a simple sonication process (bath-type ultrasound washer; Honda Electronics-W-118T; 100 W/cm² and 300 kHz frequency). After then, as-synthesized ZrO₂@chitosan was characterized by FESEM, XRD and EIS. The ZrO₂@chitosan nanocomposite modified glassy carbon electrode shows excellent electrochemical sensing performance towards anti-tuberculosis drug (rifampicin). Furthermore, the ZrO₂@chitosan modified and fabricated electrochemical sensor showed a wide linear range between 0.015 µM and 547.4 µM and nanomolar detection limit (7.5 nM). Moreover, the ZrO₂@chitosan modified electrode showed selectivity towards the detection of anti-tuberculosis drug (rifampicin). The ZrO₂@chitosan nanocomposite film modified non-enzymatic sensor has high stable and good reproducible towards the detection of rifampicin. In addition, the as-synthesized ZrO₂@chitosan nanocomposite modified electrode has been applied to the determination of rifampicin in biological samples such as human serum and urine samples.

A sensitive electrochemical determination of chemotherapy agent using graphitic carbon nitride covered vanadium oxide nanocomposite; sonochemical approach

We have developed a graphitic carbon nitride covered vanadium oxide nanocomposite (V₂O₅@g-C₃N₄) by a simple sonochemical approach (50 kHz and 150 W/cm²). Furthermore, the morphology and chemical composition of the V₂O₅@g-C₃N₄ nanocomposite was carried out by X-rays diffractometry (XRD), transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). Furthermore, the V₂O₅@g-C₃N₄ nanocomposite modified electrode was investigate electrochemical behavior of the anticancer drug. Compared with bare SPCE, V₂O₅/SPCE and g-C₃N₄/SPCE, V₂O₅@g-C₃N₄ modified SPCE showed highest current response towards anti-cancer drug (methotrexate). Furthermore, the modified sensor exhibits with a sharp peaks and wide linear range (0.025-273.15 μM) by using DPV with the sensitivity of 7.122 μA μM^-1 cm^-2. Notably, we have achieved a nanomolar detection limit (13.26 nM) for the DPV detection of methotrexate. Further, the practicability of the V₂O₅@g-C₃N₄ nanocomposite modified sensor can be used for real time sensing of methotrexate in drug and blood serum samples with good recover ranges. It has potential applications in routine analysis with high specificity, excellent reproducibility and good stability.

Novel sonochemical synthesis of Fe3O4 nanospheres decorated on highly active reduced graphene oxide nanosheets for sensitive detection of uric acid in biological samples

In this study, a super-active Iron (II, III) oxide nanospheres (Fe₃O₄ NPs) decorated reduced graphene oxide (rGOS) nanocomposite was developed. Fe₃O₄ NPs were stabilized on rGOS through electrostatic interactions in the aqueous medium. This process involves an ultrasound assisted reduction reaction of the GOS. The as-synthesized Fe₃O₄ NPs@rGOS was characterized through the HRTEM, SEM, XRD, Raman, elemental mapping and EDX analysis. The Fe₃O₄ NPs@rGOS modified GCE was developed for the determination of biomarker. Uric acid is important biomarker based on gout and kidney stone with high adverse effect in human body. The results obtained showed that the modified electrode Fe₃O₄ NPs@rGOS shows good electrochemical reduction peak compared to bare electrode and control electrodes. The Fe₃O₄ NPs@rGOS modified sensor linear range 0.02-783.6 µM was observed with nanomolar LOD 0.12 nM. In addition, the modified Fe₃O₄ NPs@rGOS/GCE sensor has been applied to determination of uric acid concentration in urine and blood serum samples. Furthermore, advantages of the modified sensor are high stability, repeatability and reproducibility.

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.

Facile sonochemical synthesis of porous and hierarchical manganese(III) oxide tiny nanostructures for super sensitive electrocatalytic detection of antibiotic (chloramphenicol) in fresh milk

We report the preparation of a porous and hierarchical manganese(III) oxide tiny nanostructures (Mn₂O₃ TNS) by a simple sonochemical approach. The nanocatalyst was synthesized by a bath-type ultrasound washer (Honda Electronics, W-118T) at 700 W and 300 kHz frequency. The morphology and chemical composition of the nanocatalyst were characterized by X-rays diffractometry (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 antibiotic drug (chloramphenicol) under phosphate buffer (pH 7.0). A facile sonochemical route was employed to prepare Mn₂O₃ TNS modified electrode. The screen-printed carbon electrode (SPCE) modified with Mn₂O₃ TNS was fabricated and applied for the electrochemical determination of chloramphenicol. Compared with bare SPCE, Mn₂O₃ TNS modified SPCE showed highest current response towards chloramphenicol. Furthermore, the modified sensor exhibits with a sharp peak and two linear ranges by using DPV (i) 0.015-1.28 μM with the sensitivity of 4.167 μA μM^-1 cm^-2 and (ii) 1.35-566.3 μM with the sensitivity of 7.205 μA μM^-1 cm^-2. Notably, we achieved a very low-level detection limit of 4.26 nM for the DPV detection of chloramphenicol. Further, the superior practicability of the nanosheets modified sensor can be used for real time sensing of chloramphenicol with good recover ranges.

A novel electrochemical sensor for determination of DNA damage biomarker (8-hydroxy-2'-deoxyguanosine) in urine using sonochemically derived graphene oxide sheets covered zinc oxide flower modified electrode

To explore a novel and multi-layer based graphene oxide covered zinc oxide nanoflower (ZnO NFs@GOS) as a modified electrode materials by sonochemical technique (40 kHz, 300 W). Herein, novel nanocomposite is successfully characterized by various characterization analysis (FESEM, HRTEM, XRD, XPS and (EIS) electrochemical impedance spectroscopy) and employed as high sensitive modified electrode (ZnO NFs@GOS nanocomposite) for the electrochemical determination of biomarker. 8-hydroxy-2'-deoxyguanosine (8-HDG) is one of the important cancer and oxidative stress biomarker. The results demonstrated that the ZnO NFs@GOS modified SPCE reveal well-defined electro-oxidation peak at 0.36 V (vs. Ag/AgCl). The high sensitive properties of the optimized flower like modified electrode are because of the excellent synergistic effect of the ZnO flower and the graphene oxide nanosheets, as evidenced by a superior bio-sensing performance. The nanocomposite fabricated modified biosensor was facilitating the analysis of 8-HDG in the concentration ranges of 0.05-536.5 µM with a low detection limit is 8.67 nM. The ZnO NFs@GOS modified sensor can also employed for the determination of 8-HDG in human urine samples, promising its application towards the quantification of cancer biomarker in biological samples.

A novel nanocomposite with superior electrocatalytic activity: A magnetic property based ZnFe2O4 nanocubes embellished with reduced graphene oxide by facile ultrasonic approach

Herein, a novel Zinc Ferrite nanocubes (ZnFe₂O₄ NCs) decorated reduced graphene oxide (rGO) nanocomposite have been designed through a sonochemical method. After then, as-synthesized ZnFe₂O₄ NCs/rGO was characterized by XPS, XRD, HRTEM and EIS. Furthermore, the ZnFe₂O₄ NCs/rGO nanocomposite modified GCE (glassy carbon electrode) shows excellent electrochemical sensing performance towards biomarker of 4-nitroquinoline N-oxide (4-NQ) with fast detection. 4-NQ is one of the important cancer biomarker. Moreover, the fabricated sensor showed a wide linear window for 4-NQ between 0.025 and 534.12 µM and nanomolar detection limit (8.27 nM). Further, the as-prepared ZnFe₂O₄ NCs/rGO/GCE has been applied to the determination of 4-NQ in human blood and urine samples with excellent recovery results.

One-pot sonochemical synthesis of Bi2WO6 nanospheres with multilayer reduced graphene nanosheets modified electrode as rapid electrochemical sensing platform for high sensitive detection of oxidative stress biomarker in biological sample

4-Nitroquinoline N-oxide (4-NQO) is an important tumorigenic organic compound with high adverse effect in the human body. In this study, a novel Bismuth Tungstate nanospheres (Bi₂WO₆) decorated reduced graphene oxide (Bi₂WO₆/rGOS) nanocomposite have been designed through a sonochemical method. The as-synthesized Bi₂WO₆/rGOS was characterized through the HRTEM, FESEM, XPS, EIS and XRD. Furthermore, the nanocomposite modified glassy carbon electrode (GCE) was developed for the determination of 4-NQO. The results showed that the Bi₂WO₆/rGOS nanocomposite modified electrode exhibit valuable responses and excellent electrocatalytic activity. The fabricated sensor was facilitated the analysis of 4-NQO with a nanomolar detection limit (6.11 nM). Further, the as-synthesized Bi₂WO₆/rGOS modified electrode has been applied to sensing of 4-NQO in human blood and urine samples with satisfactory recovery.

Facile synthesis and characterization of erbium oxide (Er2O3) nanospheres embellished on reduced graphene oxide nanomatrix for trace-level detection of a hazardous pollutant causing Methemoglobinaemia

The nanomaterials have received enormous attention in the catalysis applications. Particularly, we have focused on the fabrication of nanocomposite for an electrochemical sensor with improved electrocatalytic performance. Herein, a rapid and sensitive electrochemical detection of nitrite is essential for assessing the risks facing ecosystems in environment. We report a simple and robust ultrasonic-assisted synthetical route via prepared Er₂O₃ nanoparticles decorated reduced graphene oxide nanocomposite (Er₂O₃ NPs@RGO) modified electrode for nitrite detection. The composition and morphological formation were characterized by XRD, XPS, FESEM, and HRTEM. The amperometric (i-t) and cyclic voltammetry were exhibits tremendous electrocatalytic capability and superior performance toward nitrite oxidation. A sensitive and reproducible amperometric nitrite sensor was fabricated which able to detect trace concentration as 3.69 nM and excellent sensitivity (24.17 µA µM^-1 cm^-2). The method worked well even in cured meat and water samples and the results has indicates the reliability of the method in real-time analysis.

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.

Ultrasound-assisted synthesis of tungsten trioxide entrapped with graphene nanosheets for developing nanomolar electrochemical (hormone) sensor and enhanced sensitivity of the catalytic performance

Herein, we have reported a simple sonochemical synthesis of multi-layer graphene covered tungsten trioxide nanoballs (WO₃ NBs) and the nanocomposite was characterized by FESEM, HRTEM, XRD, XPS, CV and EIS. Furthermore, progesterone (PGT) is a preferred marker for various biological problems like pregnancy problem, mood swings, anxiety, depression, nervousness and body pain. Therefore, its selective and sensitive determination in various biological fluids is beneficial for the evaluation of malformation problems. We describe the fabrication of an amperometric and non-enzymatic biosensor based on WO₃ NBs@GR nanocomposite modified electrode for nanomolar detection of PGT. The results showed that the nanocomposite modified electrode exhibit well-defined electro-oxidation peak compared to bare and control electrodes, demonstrating the superior electrocatalytic ability and performances. The fabricated modified sensor was facilitates the analysis of PGT in the concentration ranges of 0.025-1792.5 µM with a low detection limit of 4.28 nM. Further, the as-prepared WO₃ NBs@GR electrode has been applied to determination of PGT in human blood samples with outstanding recovery results and more importantly, the facile and environment-friendly sonochemical construction strategy extended here, may be open a cost-effective way for setting up the nanocomposites based (bio) sensing platform.

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.

Applications of MxSey (M = Fe, Co, Ni) and Their Composites in Electrochemical Energy Storage and Conversion

Transition-metal selenides (M_xSe_y, M = Fe, Co, Ni) and their composites exhibit good storage capacities for sodium and lithium ions and occupy a unique position in research on sodium-ion and lithium-ion batteries. M_xSe_y and their composites are used as active materials to improve catalytic activity. However, low electrical conductivity, poor cycle stability, and low rate performance severely limit their applications. This review provides a comprehensive introduction to and understanding of the current research progress of M_xSe_y and their composites. Moreover, this review proposes a broader research platform for these materials, including various bioelectrocatalytic performance tests, lithium-sulfur batteries, and fuel cells. The synthesis method and related mechanisms of M_xSe_y and their composites are reviewed, and the effects of material morphologies on their electrochemical performance are discussed. The advantages and disadvantages of M_xSe_y and their composites as well as possible strategies for improving the storage and conversion of electrochemical energy are also summarized.