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Nitrofurantoin (NFT) is mainly used in humans for the treatment of urinary tract infections. NFT is used as feed additives in animals, due to its broad antimicrobial activity. However, it shows more side effects on human health and the environment. Therefore low-cost, portable, and rapid sensors are necessary for the detection of NFT in real samples. Herein, we successfully developed an electrochemical sensor using a glassy carbon electrode (GCE) modified with gadolinium orthoferrite (GdFeO3) decorated on reduced graphene oxide (RGO) nanocomposite for the detection of NFT. The facile hydrothermal method was used to synthesis a novel GdFeO3/RGO nanocomposite, the morphological and structural characterization was confirmed by the FESEM, HRTEM, EDX, XRD, Raman, and XPS techniques. The formation mechanism of GdFeO3/RGO nanocomposite had been discussed. The effective intercalation of the nanostructured GdFeO3 to the RGO sheets leads to the significant enhancement in physicochemical properties such as electrical conductivity, electro-active surface area, structural stability, and electrochemical activity, which was observed from the EIS and CV experimental results. The electrochemical studies established that the developed GdFeO3/RGO sensor was highly sensitive and selective to NFT. Moreover, the GdFeO3/RGO sensor exhibits good sensitivity of 4.1985 μA μM−1 cm−2, a low detection limit (LOD) of 0.0153 µM and a linear range from 0.001 to 249 µM for NFT detection under optimized experimental conditions. In addition, the investigation of storage time on the CV response of the GdFeO3/RGO sensor indicates superior stability. Owing to these extraordinary analytical advantages, the as-fabricated sensor was applied to detect the NFT levels in human urine and river water samples with satisfactory results.

Three-dimensional (3D) flower-like hierarchical carbon superstructures (CSs) have attracted significant attention for electrochemical sensor application due to their high specific surface area, mor...

The electrochemical sensor has received considerable attention because of the future on-time monitoring technologies. To meet the requirements of on-time monitoring applications, it is of prodigiou...

The development of effective heterogeneous catalysts for refractory organic pollutants removal is highly desirable. Herein, a series of 0D/2D hybrids with FeOOH quantum dots intimately anchored on the surface of the semiconductor nanosheets were fabricated and used as photo-Fenton catalysts for tetracycline hydrochloride (TCH) degradation. The optimized FeOOH/BOBC-2 hybrids exhibited superior TCH removal efficiency than that of pure BOBC-2 and FeOOH, which was 2.14 and 2.08 times higher than BOBC-2 and FeOOH. In addition, the influential factors, including the dosage of the catalyst, initial concentration of the TCH, the amount of H2O2 and initial pH were investigated. Detailed characterizations suggest that the enhanced specific surface areas and the effective separation of the photoinduced charge carriers make great contributions to the improvement of the photo-Fenton performance. Meanwhile, the effective charge mobility could promote the conversion between Fe3+ and Fe2+, boosting the activation of H2O2. It is expected this work could provide a common strategy for the fabrication of effective catalyst for environmental remediation.

In this report, cobalt(II)-doped cobalt oxide (Co–Co2O4) rose-like nanostructures were synthesized via a facile one-step ultrasonication method. The as-prepared nano Co–Co2O4 was then utilized for the sensitive quantification of the prophylactic drug furazolidone (FUZ). Various physicochemical methods, including X-ray powder diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy, were used to confirm the successful formation of the Co–Co2O4 nanostructures. The superior active surface area and larger pores of Co–Co2O4 enhance the electrocatalytic activity towards FUZ detection. The electrochemical performance of Co–Co2O4 towards FUZ was explored using the voltammetry method, with the obtained results suggesting that the proposed Co–Co2O4 sensor exhibits excellent catalytic activity towards FUZ. Under the optimized conditions, the sensor exhibits two wide linear ranges (0.05–285 μM; 285–1122.15 μM) with a low limit of detection (8 nM) and high sensitivity (2.349 μA μM−1 cm−2). Besides this, the proposed sensor exhibits high stability, reproducibility, and repeatability. Moreover, anti-interference experiments were carried out to explore the precise detection of FUZ in the presence of similar compounds.

A high-performance electrochemical sensing platform based on CuS nano-globules is efficiently developed. The CuS nano-globules are synthesized through a hydrothermal process. All the important physical characteristics of the nanomaterial such as crystal architecture, morphology, topography and composition are investigated. To better demonstrate the electrochemical sensing capability of CuS nano-globules reinforced electrodes, hydroquinone (HQE) is chosen as an analyte. Upon the electrochemical investigation, the CuS-based sensor displayed an enhanced detection limit of 0.135 μM with a linear range of 1–2287 μM. The overall sensing performance of CuS nano-globules-equipped electrode towards HQE is very impressive with good stability and reproducibility. These investigative results evidently indicate the superior electrochemical properties of CuS nano-globules and they can be highly recommended for real-time analysis.

Simple chemical synthesis is highly efficient to develop metal oxide composites as active electrode materials for an electrochemical sensor displaying enhanced catalytic sites, fast kinetics, and easy accessibility to target molecules. In this work, a cobalt oxide/tin oxide (Co3O4/SnO2) composite was prepared by a facile co-precipitation method and employed for the voltammetric determination of ornidazole (ODZ). The structural and morphological properties of the as-synthesized materials were studied through XRD, FT-IR, BET, FE-SEM, TEM, and XPS analyses. The electrochemical activity was investigated using cyclic voltammetric (CV) and linear sweep voltammetric (LSV) techniques. The electrochemical signal shows that the modified glassy carbon electrode (Co3O4/SnO2/GCE) revealed superior sensing ability in rapid ODZ detection compared to a single component of Co3O4 or SnO2. The performance was investigated over a wide linear range of 0.2 to 1185.8 μM with a low detection limit of 0.059 μM for ODZ, respectively, at a low-cost Co3O4/SnO2 modified electrode. Good selectivity was observed in the presence of NFT, 2-NA, and Cd2+ by the ODZ sensor. Furthermore, the excellent stability, repeatability, and reproducibility suggest that the constructed electrode based on Co3O4/SnO2/GCE is promising for real-time application in water samples.

Crystal defects are crucially important in semiconductor photocatalysis. To improve the reactivity of photocatalysts and attain desirable solar energy conversion, crystal defect engineering has gained considerable attention in real catalysts. Herein, we engineered crystal defects and mediate oxygen vacancies in host Bi2WO6 crystal lattice via varying content of Ti dopant to fabricate single-unit-cell layered structure, resulting in enhanced visible-light-driven photocatalytic efficiency. Density functional theory (DFT) calculations verified that the substitution of Bi cation in the crystal structure of Bi2WO6 can induce a new defect level, and increase the density of states (DOS) at the valence band maximum, which not only improve the charge dynamic but also the electronic conductivity. Remarkably, the single-unit-cell layers Ti-doped Bi2WO6 structure casts profoundly improved photocatalytic performance towards ceftriaxone sodium degradation, Cr(VI) reduction, and particularly higher photocatalytic H2 production rate, with a 5.8-fold increase compared to bulk Bi2WO6. Furthermore, the photoelectrochemical measurements unveil that the significantly higher charge migration and charge carrier dynamic counts for the elevated photocatalytic performance. After careful examination of experimental results, it was proved that the Ti doping mediated crystal defects, and engendered oxygen vacancies are critically important for controlling the photocatalytic performance of Bi2WO6.

A simple hydrothermal process has been used to prepare a carbon nanofiber/copper chromium dioxide (CNF/CuCrO2) composite for the selective detection of 4-nitrophenol (4-NP) and supercapacitor applications. The electrochemical sensor was developed with a glassy carbon electrode (GCE) modified with the CNF/CuCrO2 composite by the drop-casting method. The structural formation of the prepared materials was confirmed by infrared spectroscopy, electrochemical impedance spectroscopy, Raman spectroscopy, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. To investigate the electrochemical efficiency of the electrode, various electroanalytical techniques, namely, differential pulse voltammetry (DPV), cyclic voltammetry (CV) and galvanostatic charge–discharge tests, were employed. The GCE/CNF/CuCrO2 modified electrode exhibited excellent electrocatalytic behavior for the detection of 4-NP under optimized conditions with a low detection limit (0.022 μM), long linear response range of 0.1–150 μM, and high sensitivity (20.02 μA μM−1 cm−2). The modified electrode was used for the detection of 4-NP in real samples with satisfactory results. In addition, the GCE/CNF/CuCrO2 electrode has advantages such as stability, reproducibility, repeatability, reliability, low cost, and practical application. The CNF/CuCrO2 composite coated Ni-foam electrodes also exhibited excellent supercapacitor efficiency, with a high specific capacitance of up to 159 F g−1 at a current density of 5 A g−1 and outstanding cycling stability. Hence, the CNF/CuCrO2 composite is a suitable material for 4-NP sensors and energy storage applications.

In this work, Ni-doped ZrO2 nanoparticles (NPs) were used to decorate multi-walled carbon nanotubes (MWCNTs) to obtain a Ni-ZrO2/MWCNT nanocomposite, which acted as an efficient electrode material for the highly sensitive electrochemical detection of the anti-inflammatory drug 5-amino salicylic acid (5-ASA). The Ni-ZrO2 NPs were obtained through a facile co-precipitation method, and the subsequent support of these Ni-ZrO2 NPs onto MWCNTs was accomplished via an ultrasonication technique. Supporting Ni-ZrO2 NPs on MWCNTs not only results in excellent catalytic properties, but it also substantially enhances the surface area, electrical conductivity, and electron transfer process. The electrochemical activity of the synthesized Ni-ZrO2/MWCNT nanocomposite was systematically investigated via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The constructed Ni-ZrO2/MWCNT-modified glassy carbon (GC) electrode manifests superior electrocatalytic oxidation activity toward 5-ASA, with a lower peak potential compared with Ni-ZrO2-NP- and MWCNT-modified GC electrodes. Importantly, the proposed biosensor exhibited excellent sensitivity during the detection of 5-ASA with a wide linear concentration range (0.001-500 μM) and a low detection limit of 0.0029 μM. Moreover, the biosensor demonstrated excellent repeatability, reproducibility, stability, and high specificity toward 5-ASA detection in the presence of different interfering species. Furthermore, the biosensor showed satisfactory recovery rates in complex biological samples, such as human blood serum, human urine, and 5-ASA tablet samples.

In modern farming, pesticides are extensively used to deliver high-yield harvests with no concern about the amount of toxicity involved in the agriculture process. The continuous usage of pesticide...

The synthesis of ordered nanosized intermetallic compounds is of specific interest in tuning their surface properties to obtain enhanced electrocatalytic activity and selectivity, used for various ...

In this study, a nanostructured CuSn(OH)6 microsphere decorated on reduced graphene oxide (CSOH/rGO) was prepared by a co-precipitation method followed by ultrasonication, which was used for the se...

The stable Ni(OH)2 ultrafine nanosheet combined with Bi2MoO6 to form heterojunction have been fabricated successfully by a simple and mild one-step solvent-thermal method. In this work, the Ni(OH)2/Bi2MoO6heterojunction increased the absorption range of visible light compared to the pure Bi2MoO6, from the UV–visible diffuse reflectance spectrum (DRS), thus greatly improving the degradation rate of organic dyes. The Ni(OH)2/Bi2MoO6heterojunctionwith different proportions was prepared by a mild one-step solvothermal method by controlling the mass fraction ratio between the nickel source and the bismuth source. The morphology and structure of the heterojunction materials were characterized by afield emission scanning electron microscopy (SEM) and a field-emission high-resolution transmission electron microscope (TEM). In this experiment, the photocatalytic properties were demonstrated by the degradation of organic dye Rhodamine B by the prepared samples. The results showed that 2%Ni(OH)2/Bi2MoO6 composite had the strongest photocatalytic performance and the maximum degradation rate was about 98% (135 min) when the Rhodamine B was degraded by visible light irradiation. It also can be found that Bi2MoO6composited by Ni(OH)2ultrafine nanosheet, compared with pure Bi2MoO6, the photocatalytic performance is improved by decreasing the recombination rate of photogenic carriers.

Nanostructured binary metal sulfides are considered as a promising electrode material because of their excellent electron transfer and good sensing behavior rather than metal oxides. As a result, the binary metal sulfides were applied in energy and electrochemical sensor applications. Herein, we propose the electrochemical sensor method based on flower-like cerium-ruthenium sulfide nanostructure (Ce–Ru–S NS) for the electrochemical sensing of trifluoperazine (TFPZ). The Ce–Ru–S NS prepared using the cost-effective one-pot hydrothermal synthesis technique. Then, the resultant materials were characterized through suitable spectrophotometric techniques and the electrocatalytic properties of the fabricated sensor were investigated by EIS, CV, and amperometric (i–t) techniques. The Ce–Ru–S material has good electrocatalytic activity towards the electrochemical oxidation of TFPZ. Significantly, the fabricated sensor demonstrates the distinct amperometric response with the lowest limit of detection (LOD) of 0.322 nM (S/N = 3), high sensitivity 2.682 μA μM−1 cm−2 and lowest oxidation potential of +0.64 V (Ag/AgCl). Furthermore, the Ce–Ru–S NS displays excellent selectivity, good reproducibility, and long-term stability. The practicability of the TFPZ sensor tested in a human urine sample.

This study assessed the synergistic effect of Ni concentration and ultrasonic assisted process on the photocatalytic dye degradation efficiency towards methylene blue (MB) and reactive red 120 (RR120) and antibacterial activity against various bacteria of ZnO nanoparticles. XRD confirms the absence of any other impurity peaks in Nickel (Ni) doped ZnO nanoparticles, disclose that Ni doping influences the lattice structure of Zn. The obvious red-shift with the increase of Ni concentration results in decreased band gap and transmittance. SEM micrograph confirms the formation of hexagonal rod and sheet like nanostructures in the Ni doped ZnO nanoparticles by the ultrasonic assisted co-precipitation method. The Ni doped ZnO nanoparticles control the recombination of charge carriers and increase the photocatalytic degradation of MB and RR120. The antibacterial result revealed that 5% Ni substituted sample is effective as an antibacterial agent to prevent the bacterial contamination. 5% Ni doped ZnO nanoparticles synthesized by ultrasonic assisted coprecipitation method is an excellent candidate for removal of methylene blue and bacteria.

The rapid and ultralow detection of toxic organophosphate chemicals is a well-known, important step to reduce adverse health issues and yet also remains challenging. Here, we show electrochemical d...

In the present work, we report a one-step pyrolysis synthesis of molybdenum nitride nanorods (MoN NRs) using ammonium heptamolybdate tetrahydrate as a precursor. Properties of MoN NRs have been imp...

Inorganic perovskite-based alkaline earth oxide materials for electrochemical sensing devices are an unwrapped research field yet to be studied. Herein, we designed a novel perovskite-type calcium stannate (CaSnO3) material with stone-shaped structural morphology synthesized by a simple coprecipitation method with the aid of urea and utilized as an electrocatalyst for the electrochemical detection of photographic developing agent metol (MT). The synthesized CaSnO3 was systematically characterized with the help of X-ray diffraction (XRD), Raman, Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy, elemental mapping analysis, high resolution transmission electron microscope (HR-TEM), and electron spectroscopy for chemical analysis (ESCA). Furthermore, the electrochemical property of CaSnO3 was examined by cyclic voltammetry and differential pulse voltammetry techniques. As a result, CaSnO3 modified with a glassy carbon electrode (CaSnO3/GCE) implies better electrocatalytic activity with an enhanced redox peak response, wider linear range (0.01–123 μM), lower detection limit (0.003 μM), and appreciable sensitivity toward the detection of MT. In addition to that, the CaSnO3 modified electrode has excellent selectivity with the existence of potentially interfering compounds such as cationic/anionic species and biological substances. Moreover, the CaSnO3 modified electrode has better reproducibility, repeatability, and storage stability. Further, the practical viability of the synthesized CaSnO3 was investigated by using lake water as a real sample, revealing reasonable recovery results.

In this work, we developed cerium oxide/tin oxide (CeO2/SnO2) nanocatalyst with the assistance of urea by a simple sonochemical method and utilized as an efficient electrode material for electrochemical sensing of anti-inflammatory drug 5-aminosalicylic acid (Mesalamine, MES). The CeO2/SnO2 nanoparticles (NPs) were systematically characterized in terms of their crystal structure, morphologies, and physicochemical properties using XRD, Raman, FESEM, HR-TEM, EDX, mapping, and XPS analysis. The characterization results clearly confirmed that the prepared NPs was formed in the phase of CeO2/SnO2 without any other impurities. The electrochemical properties of CeO2/SnO2 NPs were investigated by EIS, CV, and DPV techniques. The CeO2/SnO2 NPs (9.6 μA) modified GCE demonstrated an excellent and improved electrocatalytic activity in terms of higher anodic peak current and lower peak potential when compared to bare GCE (6.7 μA) and CeO2 NPs/GCE (8.2 μA) for the sensing of MES. The CeO2/SnO2 NPs/GCE shows broader linear response range and lower detection limit of 0.02–1572 μM and 0.006 μM, respectively. Moreover, other potentially interfering compounds such as a similar functional group containing biological substances and inorganic species have no interference effect towards MES sensing. In addition, the practicability of the CeO2/SnO2 NPs/GCE was tested by real sample analysis in commercial MES tablet, human urine, and serum samples with the appreciable recovery results.

In this work, lanthanum molybdate nanospheres (LMNSs) were prepared by employing a co-precipitation methodology, and their electrochemical activity against nitrofurantoin (NF) was reported. The physico-chemical nature of LMNSs, and their texture and morphology were characterized by using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, powder X-ray diffraction (PXRD) and field emission scanning electron microscopy (FE-SEM) combined with energy-dispersive X-ray spectroscopy (EDX). The electrochemical studies were performed by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The ensuing LMNSs have a fantastic active surplus area and uplifted surface volume ratio, which drives the selective and sensitive detection of NF. The as-synthesized LMNSs were coated on a screen-printed carbon electrode (SPCE) by a drop cast method, and the constructed LMNSs/SPCE acts as a potential sensing material towards the reduction of NF. Also, the designed sensor exhibits a broad linear range from 0.01 to 144 μM with a lower detection limit of 72 nM and sensitivity equivalent to 2.94 μA μM−1 cm−2 for the detection of NF. Meanwhile, the fashioned sensor has good selectivity in the presence of metal ions, biomolecules and similar nitro group containing drugs.

In this study, the sensitive and selective detection of bisphenol A (BPA) was achieved using a screen-printed carbon electrode (NFO/SPCE) modified with hydrothermally synthesized NiFe2O4 nanoparticles. The crystalline structure, surface morphology and electrical conductivity of the nanoparticles were analyzed using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The as-prepared NiFe2O4 (NFO) nanoparticles exhibited a cubic crystal structure with an average crystallite size of 16 nm, as calculated using the Scherrer equation. As determined by cyclic voltammetry (CV), NFO/SPCE exhibited excellent electrochemical oxidation towards the detection of BPA. Subsequently, differential pulse voltammetry (DPV) studies revealed a rapid and stable response to the consecutive addition of BPA in a linear range of 0.02–12.5 μM with a lower limit of detection (LOD) of 6 nM, which was superior to previously reported results. In addition, the proposed method showed good stability and excellent repeatability for the determination of BPA in real samples.

The development of novel chemical sensors for pesticide detection has found particular application in the area of environmental monitoring. However, designing primary sensors as weapons to destroy contaminants (e.g., paraoxon-ethyl) in water and soil remains a challenge. Herein, we show different strategies, such as modification of TiO2 NPs through La3+ doping and decoration of f-MWCNTs, which can provide possibilities for notable developments in electrocatalytic performance. Using this approach, we introduce an active La3+ doped TiO2 NP decorated f-MWCNT electrocatalyst for pollutant monitoring applications. Thereby, our findings move towards an outstanding LOD (0.0019 μM) performance, high selectivity, and exceptional sensitivity (7.6690 μA μM−1 cm−2) on an as-presented catalytic platform for a PE sensor. Interestingly, the practical applicability of the suggested catalyst shows a rich sensing platform for PE-contaminated environmental samples.

Metal tungstates are considered efficient electrocatalysts in the area of electrochemical sensors. Herein, we prepared an alkaline-earth-metal-based transition metal tungstate (SrWO4) through a simple co-precipitation method. Further, to enhance the electrocatalytic activity, commercially available boron nitride (BN) was used to prepare a SrWO4/BN composite via an ultrasonication method. The as-prepared SrWO4/BN composite was scrutinized using XRD, FTIR, FE-SEM, EDS, elemental mapping, and HR-TEM analysis for determining the phase purity, functional groups, and structural morphology of the as-prepared composite. The electrochemical performance of the SrWO4/BN composite was analyzed with the help of cyclic voltammetry and linear sweep voltammetry techniques using a three-electrode system. As-modified SrWO4/BN with a glassy carbon electrode (SrWO4/BN/GCE) exhibits better electrochemical activity towards the reduction of ornidazole (OD), with a lower cathodic peak potential (Epc = −0.62 V) and an increased cathodic current (Ipc = −21.3 μA) compared to other modified electrodes for the detection of OD, and a larger linear range (0.01–437 μM) and lower limit of detection (0.003 μM). Further, interference studies were carried out in the presence of hazardous metal anions and cations, some biological compounds, and similar structural compounds to examine the selectivity of the proposed sensor; SrWO4/BN/GCE reveals good selectivity. In addition, the practical feasibility of the sensor was inspected using commercial OD tablet and lake water samples, disclosing the acceptable recovery properties of the sensor in the presence of real samples. From all the obtained results, the proposed sensor utilizing the SrWO4/BN/GCE composite prepared via an ultrasonication technique is shown to be an appropriate candidate for the detection of OD.

Investigating ecofriendly sustainable materials with excellent electrocatalytic activity is a pivotal approach for the analysis field. The present work reports on the preparation of novel three-dim...

Benefiting from the rich redox chemistry, high electrical conductivity and synergistic effect from two metal ions, the binary metal sulphides received tremendous attention in various applications. As a result, the MoS2–RuS2 nanomaterial was synthesized through the simple one-pot hydrothermal technique. The electrocatalytic activity of the as-synthesized nanomaterial was exploited towards the electrochemical detection of antibiotic drug sulphadiazine (SDZ). The electrocatalytic oxidation of the SDZ exhibited lowest anodic peak potential and ehanced anodic peak current rather than other modified electrodes. Notably, an excellent electrochemical performance with very lowest limit of detection (LOD) of 0.004 μM, appreciable linear range from 0.01 μM to 598.7 μM and high sensitivity (2.333 μA μM−1 cm−2) was obtained at MoS2–RuS2 modified electrode. Moreover, well anti-interfering property, good operational stability, repeatability and reproducibility was achieved. Facinatingly, the practicability of the modified electrode demonstrated in milk and human serum samples.

We demonstrate the different types of synthesis processes (hydrothermal, microwave and simple chemical synthesis) to prepare the Fe doped molybdenum diselenides (H-FeMoSe2, M-FeMoSe2, and C-FeMoSe2) and investigate their relevant electrocatalytic activities. The Fe doped MoSe2 exhibited an enhanced charge transfer conductivity and electrocatalytic activity. Especially, the H-FeMoSe2 with vertically aligned structures facilitate the abundant exposed active edge sites. Thus, H-FeMoSe2 modified screen-printed carbon electrode (H-FeMoSe2/SPCE) exhibited the lower Rct and better active surface area than that of M-FeMoSe2/SPCE and C-FeMoSe2/SPCE. As well as, the electrochemical sensing of mesalamine (MES) at H-FeMoSe2/SPCE is comparatively 0.46 and 1.28 fold higher than that obtained at M-FeMoSe2/SPCE and C-FeMoSe2/SPCE respectively. Thus, H-FeMoSe2/SPCE was concluded as an excellent electrocatalyst for sensing of MES and performed DPV technique. As the results, very low detection limit (0.8 nM) of MES was achieved at H-FeMoSe2/SPCE. Hence, the selected H-FeMoSe2/SPCE was successfully subjected to the real-time detection of MES by using a paramedical tablet and reported the excellent recovery range.

The transition metal tungstates have attracted and gained much interest in recent years because of the excellent electrocatalytic properties. Herein, we have explored the electrochemical activity o...

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.

The one-step synthesis of heteroatom-doped porous carbons is reported with the in situ formation of cobalt oxide nanoparticles for dual electrochemical applications (i.e., electrochemical sensor and supercapacitor). A single molecular template of zeolitic imidazole framework-67 (ZIF-67) was utilized for the solid-state synthesis of cobalt oxide nanoparticle–decorated nitrogen-doped porous carbon (Co3O4@NPC) nanocomposite through a facile calcination treatment. For the first time, Co3O4@NPC nanocomposite derived from ZIF-67 has been applied as an electrode material for the efficient electrochemical detection of anticancer drug flutamide (FLU). The cyclic voltammetry studies were performed in the operating potential from 0.15 to − 0.65 V (vs. Ag/AgCl). Interestingly, the fabricated drug sensor exhibited a very low reduction potential (− 0.42 V) compared to other reported sensors. The fabricated sensor exhibited good analytical performance in terms of low detection limit (12 nM), wide linear range (0.5 to 400 μM), and appreciable recovery results (~ 98%, RSD 1.7% (n = 3)) in a human urine sample. Hereafter, we also examined the supercapacitor performance of the Co3O4@NPC-modified Ni foam in a 1M KOH electrolyte, and noticeable a specific capacitance of 525 F g−1 at 1.5 A g−1 was attained, with long-term cycling stability. The Co3O4@NPC nanocomposite supercapacitor experiments outperform the associated MOF-derived carbons and the Co3O4-based nanostructure-modified electrodes.

Gadolinium tungstate (Gd2(WO4)3) has acquired much attention owing to its exclusive transport properties and excellent thermal and chemical stability. In this work, we demonstrate that two-dimensional (2D) gadolinium tungstate nanoflakes (GW Nfs) are synthesized by a coprecipitation method and represent novel architectures for efficient catalysis, which could be used in electrochemical sensing and photocatalytic degradation of the postharvest fungicide carbendazim (CBZ). The physicochemical properties of GW Nfs were studied by using XRD, Raman, TEM, EDX, and XPS, which show the formation of GW as a nanoflake-like structure with a well crystallized nature. The as-prepared GW Nfs revealed an admirable electrochemical response for CBZ detection with an LOD of 0.005 μM, a wide-ranging linear response of 0.02 to 40 μM, and a notable sensitivity of 0.39 μA μM-1 cm-2. Furthermore, the GW-Nf-modified electrode has a good recovery for CBZ in the study of real samples such as rice and soil washed water samples. Moreover, GW Nfs have a promising photocatalytic activity for CBZ degradation. The GW Nfs could degrade CBZ at greater than 98% efficiency and mineralize above 74% of the CBZ molecules in the presence of visible light irradiation with superior stability even after many cycles. Subsequently, the electrochemical and photocatalytic mechanisms were provided in detail.

Material combinations of semiconductor with conducting polymer are gaining growing interest due to their enhanced activities in photocatalysis as well as electrochemical sensing. In this present wo...

To dates, the facile synthesis of inorganic–coated organic polymer composite has received greater attention in the order of research fields including advanced materials and electrochemical analysis owing to the complementary or synergistic effects. In this context, Pr2O3 and Pr2O3 coated polystyrene (Pr2O3/PS) inorganic–organic colloidal composite were prepared via ultrasound-induced radicals initiated precipitation and dispersion polymerization methods. The synthesized Pr2O3/PS composite was systematically studied by FE-SEM, TEM, EDX, FT-IR, XRD, and XPS analysis. This composite modified glassy carbon electrode (Pr2O3/PS GCE) was utilized to construct a novel electrochemical sensor for the detection assay of chemotherapy agent methotrexate (MTA). Under optimal condition, the designed sensor showed outstanding performance for MTA trace level detection over the linear concentration range of 0.01–236 µM with a detection limit of 0.8 nM for MTA. Furthermore, the prepared sensor accomplished excellent stability and relevant reproducibility, in addition to reliable practical assay in real human blood serum and urine samples. Besides, the possible MTA sensing mechanism of Pr2O3/PS GCE has been deliberated in detail. Our finding suggested that the developed Pr2O3/PS composite might be a favorable material for the fabrication of the high-performance electrochemical sensor.

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.

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.

An electrochemical sensor based on a glassy carbon electrode (GCE) modified by three-dimensional graphene (3D-GE) and polyglutamic acid (PGA) was developed to quantitatively detect Amoxicillin (AMX), a worldwide used antibiotic. AMX response at PGA/3D-GE/GCE involving the transfer of one electron and an equal number of protons were determined using electrochemical approaches. Density functional theory simulations were performed to give insights on the reaction mechanism of AMX on the surface of the modified electrode. When the optimization of the experimental conditions was completed, the linear range of AMX was 2–60 μM. Besides, the detection limit was calculated as 0.118 μM (S/N = 3). And the modified electrode could detect the concentration of the AMX in human urine samples. Overall, the developed PGA/3D-GE/GCE for determination of AMX shows great potentials in practice.

A novel electrochemical sensor based on ruthenium sulfide nanoparticles decorated activated graphite sheets (RuS2/AG) was designed and fabricated for the determination of antipsychotic drug chlorpromazine hydrochloride (CPZ). Activated graphite sheets (AG) were prepared by non-explosive, non-hazardous and simple chemical activation technique. Then, the AG sheets were used for the synthesis of RuS2/AG nanocomposite by single step hydrothermal synthesis method. The synthesized materials were characterized using field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), Raman spectrometer, X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The synergistic effect of the RuS2/AG nanocomposite was applied for the determination of CPZ by cyclic voltammetry (CV) and differential pulse voltammetric (DPV) techniques. Fascinatingly, the RuS2/AG nanocomposite exhibited the excellent electrocatalytic activity and detects the CPZ at very lowest oxidation potential about 0.60 V vs Ag/AgCl in pH-7 PB solution. Moreover, the lowest LOD 8 nM and wider linear ranges from 0.05 to 79.75 and 79.75–1249 μM was obtained towards the CPZ determination. Besides, the proposed sensor shows the good selectivity, satisfactory repeatability, reproducibility and stability. Furthermore, the real time application was evaluated in pharmaceutical tablets and human urine samples.

Herein, a novel iron nitride nanoparticles (Fe2N NPs) decorated reduced graphene oxide (rGOS) nanocomposite have been designed through a solvothermal method and followed by a nitridation process. After then, as-synthesized Fe2N NPs@rGOS was characterized by HRTEM, FESEM, XPS, XRD, and EIS. Furthermore, the nanocomposite modified SPCE (screen-printed carbon electrode) shows excellent electrochemical sensing performance towards biomarker of 4-nitroquinoline N-oxide (4-NQO) with fast detection. 4-NQO is one of the important cancer biomarker. Moreover, the fabricated sensor showed a wide linear window for 4-NQO between 0.05–574.2 μM and nanomolar detection limit (9.24 nM). Further, the as-prepared Fe2N NPs@rGOS/SPCE has been applied to the determination of 4-NQO in human blood and urine samples with recoveries close to 100%.

A simple and accurate electrochemical sensor for the detection of tryptophan (TRP) was developed by modifying the surface of glassy carbon electrode (GCE) with silver molybdate incorporated reduced graphene oxide (AgM/RGO) composite. The AgM/RGO composite was synthesized by single step hydrothermal synthesis. The as-prepared AgM/RGO composite was confirmed by the various analytical and spectroscopic techniques. The electrochemical properties of the AgM/RGO composite was investigated by cyclic voltammetry and amperometric method. The AgM/RGO modified GCE shows an excellent electrochemical detection towards of TRP. The combination of AgM and RGO are not only enhanced the electrochemical properties of the composite but also improved the electron transfer between the electrode and TRP. Under the optimal condition, the proposed sensor was showed a wide linear range from 0.02 to 146.96 μM with a low detection limit of 0.0057 μM. Besides, the electrode sensitivity was calculated to be 4.327 μA μM−1 cm2. Remarkably, the proposed sensor exhibited good selectivity, stability, reproducibility and repeatability. The AgM/RGO/GCE was successfully applied to TRP determination in food and biological samples.

The hybrid rGO-TiO2/Co3O4 nanocomposite was successfully synthesized through co-precipitation method. The structural, morphological, compositional and optical properties of the as synthesized nanocomposite were characterized by X-ray diffraction (XRD), Field Emission scanning electron microscopy (FESEM), energy dispersive X-Ray Spectroscopy (EDS), Fourier transformation infrared spectroscopy (FTIR), UV–visible spectrophotometer (UV–vis) and photoluminescence (PL). XRD, EDS and FTIR confirms the existence of rGO-TiO2/Co3O4 in the prepared nanocomposite. FESEM confirms that the TiO2/Co3O4 nanocomposite are adsorbed on the surface of the rGO. UV–Vis and PL spectra revealed that the absorbance and emission occurred at visible region, which greatly supports the photocatalytic dye degradation through the electron-hole separation. The percentage decolorization of methylene blue dye solution was higher with lesser time compared to crystal violet dye. This result concludes that the commercialization of rGO/TiO2/Co3O catalyst may useful for treating various dyes in industries.

The present work reports the facile and cost-effective synthesis of rod like structured nickel doped bismuth sulphide (Ni-Bi2S3) via the ultrasonication process. The sonochemical synthesis technique is rapid, simple, non-explosive, and harmless than other conventional synthesis technique. After the synthesis, the resultant material was characterized through the various spectrophotometric techniques including FESEM, EDX, XRD, XPS and EIS. After the structural evaluation, as-synthesized Ni-Bi2S3 was applied for the electrocatalytic detection of promethazine hydrochloride (PMTZ) using CV and amperometry (i-t) techniques. Captivatingly, excellent electrocatalytic performance with the wider linear range from 1 nM to 163.17 µM was obtained for the electrochemical determination of PMTZ. The limit of detection (LOD) and sensitivity calculated around 0.4 nM and 2.904 μA µM−1 cm−2, respectively. Besides, an excellent selectivity, satisfactory reproducibility and good stability of the Ni-Bi2S3 modified electrode were checked towards the electrochemical determination of PMTZ. Furthermore, the real time application of PMTZ sensor was established in human serum and urine samples.

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.

A flexible and promising amperometric glucose biosensor was reported using direct immobilization of glucose oxidase (GOx) on chitosan supported mesoporous carbon (MPC-CHT) nanocomposite. The availability of more functional groups particularly amine groups, the CHT was selected as an immobilization matrix as well as cross linker for GOx. The MPC-CHT-GOx composites were characterized well and discussed in details. The MPC-CHT-GOx modified electrode accelerates fast electron transfer on the electrode surface due to the excellent intermolecular interaction between the CHT and GOx molecule. Besides, the MPC-CHT-GOx composite showed well-defined redox behavior with enhanced direct electron transfer (DET) of GOx in PBS, pH 7. Amperometric response of MPC-CHT-GOx modified electrode displayed a good linear response over the glucose concentration ranges from 250 μM to 3 mM with a detection limit (LOD) and sensitivity of 4.1 μM and 56.12 μA mM−1 cm−2, respectively. The MPC-CHT-GOx modified electrode also displayed good charge transfer coefficient (α) and heterogeneous rate constant (ks) values are 0.56 and 2.2182 s−1. Besides, the MPC-CHT-GOx modified electrode exhibited good bio-catalytic activity with the Michaelis-Menten saturation (Kmapp) value was about 2.14 mM. The practicability of the sensor was evaluated in biological real samples with satisfactory recoveries.

A simple, novel electrochemical sensing platform based on porous g-C3N4 (PCN) and multi-walled carbon nanotubes (MWCNTs) for the sensitive detection of uric acid (UA) has been proposed. The obtained PCN possessed good biocompatibility and large specific surface area with good dispersion, which was beneficial to electrocatalysis. The introduction of MWCNT as the conducting matrix improved the poor conductivity of PCN. Due to synergistic effect, the redox peak currents of UA substantially enhanced at PCN/MWCNT-modified electrode. The oxidation peak current exhibited linear responses to the concentration of UA in the range from 0.2 to 4 μM and 4 to 20 μM, and the limit of detection was calculated as 0.139 μM (signal-to-noise ratio of 3 (S/N = 3)). The sensor based on PCN/MWCNT-modified electrode was also successfully applied in human serums and also showed excellent selectivity, reproducibility, and stability. This work illustrated that the fabricated electrochemical sensor was promising for analytical applications.

A sensitive and selective amperometric detection of hydrogen peroxide (H2O2) sensor in biological samples was developed using platinum nanoparticles decorated graphite/gelatin hydrogel (PtNPs@GR/GLN) composite. The GLN hydrogel taking an advantage of dispersing medium as well as supporting agent for selectively welcomes H2O2 molecule on the electrode surface. The PtNPs@GR/GLN composite was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and elemental analysis. The number of PtNPs deposition cycles, effect of scan rate and solution pH were studied and discussed in details. The electrochemical behavior of PtNPs@GR/GLN modified electrode was investigated by cyclic voltammetry (CV) and showed an excellent electrocatalytic activity and lower detection potential towards the sensing of H2O2. Besides, the amperometric i-t curves displayed a fast diffusion and wide linear response range of H2O2 concentrations from 0.05 to 870.6 μM with a detection limit (LOD) of 37 nM. The PtNPs@GR/GLN modified electrode exhibited selectively detect H2O2 molecule in presence of biologically active interfering molecules. The PtNPs@GR/GLN modified electrode was successfully applied for the determination of H2O2 in biological real samples such as human serum and saliva for practical applications.

However the usage of insecticides are essential to safeguard the crops, the increase in its permissible levels imposes several health issues. The organophosphate insecticides like fenitrothion (FNT) are known for its rapid migration properties and adverse health effects. Therefore, precisely detecting the dissemination of FNT in ecology is very much essential. In this article, we reported a synthetic approach to rGO-Tungsten carbide nano-polyhedrons (rGO-WC NPHs) composite. Then economically, rGO-WC NPHs were fabricated on the screen-printed carbon electrode (SPCE) for the determination of FNT in environmental water and forest soil samples. As expected its shows moral analytical parameters, such as wider linear range of 10 nM–471.2 μM, with the very low detection limit of 1.15 nM. The sensitivity possessed by the prepared robust FNT detector is 5.3760 μAμM−1cm−2. The results acquired for the developed sensor (rGO-WC NPHs/SPCE) were also compared with the standardized HPLC method to validate the robustness of the sensor.

In this work, strontium cerate nanoparticles (SrCeO3 NPs, SC NPs) were developed through facile synthetic techniques (Ultrasound-Assisted (UA) and Stirring-Assisted (SA) synthesis) and utilized as an electrocatalyst for the selective and sensitive electrochemical detection of calcium channel blocker nifedipine (NDF). The as-prepared UASC NPs and SASC NPs were characterized using XRD, Raman, TEM, EDS, mapping, XPS and BET analysis which exposed the formation of SC NPs in the form of spherical in shape and well crystalline in nature. BET studies reveal that UASC NPs have maximum surface area than that of SASC NPs. Further, the use of the as-developed UASC NPs and SASC NPs as an electrocatalyst for the detection of NDF. Interestingly, the UASC NPs modified screen printed carbon electrode (UASC NPs/SPCE) exhibited an excellent electrocatalytic activity in terms of lower reduction potential and enhanced reduction peak current when compared to SASC NPs and unmodified SPCE. Moreover, as-prepared UASC NPs/SPCE displayed wide linear response range (LR, 0.02–174 µM), lower detection limit (LOD, 5 nM) and good sensitivity (1.31 µA µM−1 cm−2) than that of SASC NPs (LR = 0.02–157 µM, LOD = 6.4 nM, sensitivity – 1.27 µA µM−1cm−2). Furthermore, UASC NPs/SPCE showed an excellent selectivity even in the existence of potentially co-interfering compounds such as similar functional group containing drugs, pollutants, biological substances and some common cations/anions. The developed sensor was successfully employed for the determination of NDF in real lake water, commercial NDF tablet and urine samples with acceptable recovery.

In this study, a novel polystyrene:β-cyclodextrin inclusion complex-supported yttrium oxide (Y2O3)-modified glassy carbon electrode (PS:β-CD IC/Y2O3/GCE) was developed for the simultaneous determination of selected drugs, 4-aminoantipyrine (4-AAP) and acyclovir (ACV) for the first time. The results showed that PS:β-CD IC/Y2O3/GCE exhibits well-defined oxidation peak currents with a lower positive shift in peak potential in the simultaneous determination of 4-AAP and ACV compared to the bare GCE, demonstrating the superior catalytic activity. The fabricated sensor showed the linear ranges of 0.01–655 and 0.01–918 μM with low detection limits of 0.01 and 0.02 μM for the determination of 4-AAP and ACV, respectively. Further, the as-prepared PS:β-CD IC/Y2O3/GCE has been applied to the simultaneous and individual determination of 4-AAP and ACV in human urine and commercial ACV tablet samples with satisfactory recovery (98–99.3 and 88–96.6%), thereby showing a notable potential for extensive applications in the...

The Dopamine and Uric acid play a prominent part in mammalian neuronal networks, which bridges the brain and neurons. Accordingly, several types of research were passionate about the sensing of Dopamine (DA) and Uric acid (UA) in food and biological samples. Consequently, the sensing properties of notorious materials, ought to be elevated through the morphological tuning for the development of advanced DA and UA sensors. For the very first time, a comprehensively applied effective material of the DA and UA sensors, Zinc oxide (ZnO) is prepared through the microwave method with the different stoichiometric ratios of urea, such as [C4H6O4Zn · 2H2O: CH4N2O] = [1:1], [1:2], and [1:3], respectively. After that, we established the DA and UA biosensor over the cost-effective screen-printed carbon electrode (SPCE) adaption method. Thus, the ZnO adapted electrode exhibited excellent catalytic properties towards the simultaneous detection of DA and UA. It gained a broad working range between 100 nM and 374 μM for DA and 100 nM and 169 μM for UA with the ultralow limit of detection and significant sensitivity. This technique is effectively exploited for the detection of DA and UA levels in the samples of meat, wheat flour, and human urine.

A novel fluorescent sensor based on g-C3N4 nanofibers for the sensitive detection of dopamine (DA) has been proposed. We synthesized g-C3N4 nanofibers by directly hydrolyzing bulk g-C3N4 in the alkaline atmosphere (3 M NaOH). The obtained ultrathin g-C3N4 nanofibers were verified by characterizations of Transmission electronic microscope (TEM), X-ray diffractometer (XRD), Fourier transformation-infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). It was found that the fluorescence intensity of g-C3N4 nanofibers was obviously quenched by DA. Fluorescence resonance energy transfer (FRET) between DA and g-C3N4 nanofibers led to the fluorescence reduction of g-C3N4 nanofibers. The fluorescent probe based on g-C3N4 nanofibers exhibits linear responses to the concentration of DA in the range from 0 to 4 μM and 4 to 20 μM, the limit of detection is 17 nM. The fluorescent probe shows excellent stability, good selectivity with its application in serums.