Electrochemical Approach For Detection Research Articles

User-Friendly and Responsive Electrochemical Detection Approach for Triclosan by Nano-Metal-Organic Framework.

Antimicrobial resistance poses a significant challenge to public health, and is worsened by the widespread misuse of antimicrobial agents such as triclosan (TCS) in personal care and household products. Leveraging the electrochemical reactivity of TCS's phenolic hydroxyl group, this study investigates the electrochemical behavior of TCS on a Cu-based nano-metal-organic framework (Cu-BTC) surface. The synthesis of Cu-BTC via a room temperature solvent method, with triethylamine as a regulator, ensures uniform nanoparticle formation. The electrochemical properties of Cu-BTC and the signal enhancement mechanism are comprehensively examined. Utilizing the signal amplification effect of Cu-BTC, an electrochemical sensor for TCS detection is developed and optimized using response surface methodology. The resulting method offers a simple, rapid, and highly sensitive detection of TCS, with a linear range of 25-10,000 nM and a detection limit of 25 nM. This research highlights the potential of Cu-BTC as a promising material for electrochemical sensing applications, contributing to advancements in environmental monitoring and public health protection.

Ventilator-associated pneumonia diagnosis: electrochemical sensors for rapid and sensitive detection of pyocyanin

Ventilator-associated pneumonia (VAP) is a severe condition in critically ill patients that requires timely diagnosis to improve patient outcomes. In this study, we developed an electrochemical sensor for pyocyanin detection using a TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}-NiO-rGO catalyst and found that it could detect the concentration of pyocyanin required for mimicking the throat trachea’s environment (LOD: 0.2 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu $$\\end{document}g/mL). We also investigated using DNA aptamer for detecting pyocyanin, a biomarker of Pseudomonas aeruginosa, a common causative agent of VAP. Our findings suggest that the TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}-NiO-rGO catalyst without aptamer could provide a rapid and cost-effective diagnostic tool for VAP, and the electrochemical sensor has the potential to be made disposable for in vivo applications. Using the TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}-NiO-rGO catalyst offers synergistic effects that enhance the detection process’s overall electrochemical performance, sensitivity, and selectivity. This work’s results demonstrate that electrochemical detection of pyocyanin using a TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}-NiO-rGO catalyst holds great potential for various applications, such as clinical diagnostics and drug discovery. Further research and optimization of the catalyst composition, morphology, and surface modifications can contribute to advancing this pyocyanin electrochemical detection approach.

Nickel molybdate/cobalt molybdate nanoflakes by one-pot synthesis approach for electrochemical detection of antipsychotic drug chlorpromazine in biological and environmental samples

Pharmaceutical waste products have become environmental contamination and pollution which poses a significant risk to our planet. The fabrication of effective antipsychotic drug monitoring systems is greatly important to minimize their environmental problems. Therefore, the construction of mixed metal molybdates has been investigated to develop an electrochemical sensor with high sensitivity and low detection limits. In regards, we have successively synthesized nickel molybdate/cobalt molybdate (NiMoO4/CoMoO4; NCMO) through a simple co-precipitation method and their electrocatalytic activity of chlorpromazine (CPZ) evaluated. The synthesized NCMO was inspected by diverse physicochemical analyses. From the morphological study, the prepared NCMO nanoflake displays exceptionally rich surface electroactive sites. Furthermore, the electrochemical properties of the developed sensor were investigated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Accordingly, the NCMO endorses greater electrochemical behavior because of rapid electron transfer, improved electrochemical active surface area, and synergetic effect. The established electrochemical sensor displays a wide linear range and the lowest detection limit, admirable sensitivity, reproducibility, and repeatability. Finally, the real-time application of CPZ was performed in wastewater and human urine samples with reasonable recoveries.

A pilot study on an electrochemical approach for assessing transient DNA transfection in eukaryotic cells

• An approach for electrochemical detection of transfected eukaryotic cells is proposed. • Differential pulse voltammetry can detect transfected cells. • Transfected and control cells demonstrated diverse electrochemical signature. • Electrochemical response corresponds to outer membrane proteins of cells. • Electrochemical approach is suitable for detection of transfected cells. An electrochemical approach for assessing transient DNA transfection efficiency in eukaryotic cells was proposed based on direct analysis of the electrochemical signatures of control and transfected cells in the potential range of (0 ÷ + 1.1) V by the differential pulse voltammetry technique using screen-printed electrodes modified with functionalized carbon nanotubes. The differential pulse voltammetry technique permits to register 4000 cells per electrode. To the best of our knowledge, this will be the first report on the electrochemical registration of transfection process based on comparative analysis of cells. This approach can be used for the incorporation of plasmid pTagGFP2-N with a therapeutically relevant gene without using TagGFP2 as a reporter gene to express green fluorescent protein as a marker in cells. The proposed method was applied to the transfected human breast carcinoma cell line SkBr-3, diploid human fibroblast cell line Wi-38 and normal human CD4 + T lymphocytes. The electrochemical fingerprints of cells demonstrated significant differences in the behavior of transfected cells in comparison with control cells.

Electrochemical Detection of Penicillin G Using Molecularly Imprinted Conductive Co-Polymer Sensor

Antibiotics are increasingly used to treat certain bacteria that are harmful to humans. However, their inadequate or excessive use can lead to the proliferation of certain more resistant strains, which ultimately reduces their effectiveness. To counter this, it is essential to limit the amount of antibiotics ingested, particularly through animal food, if the animals themselves have received antibiotic treatment. In the case of milk, it is necessary to be able to detect quantities of antibiotics in the range of a few parts per billion. A sensor has therefore been developed for this purpose. The sensitive layer that we propose to use in this study, is based on a molecularly imprinted conductive polymer (MICP) that allows a very specific interaction and have been integrated into electrochemical detection approaches by polymerization on electrodes. The sensor is based on the measurement of the variation in conductivity of a sensitive layer deposited between two electrodes, which is influenced by the presence of the antibiotic. Although it seems possible to further improve the performance of these sensors, their use in this field seems very promising considering the obtained results.

Construction of sphere like samarium vanadate nanoparticles anchored graphene nanosheets for enhanced electrochemical detection of nitrofurantoin in biological fluids

In recent times rare earth metal vanadate (REVO) has received a lot of attention in the research of electrocatalysts . Accordingly, we construct a novel fabrication strategy nanoarchitecture for an electrochemical sensor . In addition, the highly effective nitrofurantoin (NFT) antibiotic drug is mainly used for the treatment of urinary tract infections. However, when the level of NFT use in the human body increases, the pulmonary develops toxic and many side effects. Hence, the detection of NFT in biological fluids is much important. This electrochemical detection approach is a better way to detect the NFT precisely. Herein, the pristine samarium vanadate nanoparticles (SV NPs) synthesized were Co-precipitation method. The collected sample was sintered at 450, 550, and 650 °C (denoted as SV-1, SV-2, SV-3). The above-mentioned samples were incorporated with graphene nanosheets (GNSs) through an ultra-sonication method to obtained SmVO 4 -GNSs (SVG) nanocomposites namely (SVG-1, SVG-2, SVG-3), which were utilized for various analytical, spectroscopic and microscopic techniques. Interestingly, the as-prepared SVG-2/GCE was demonstrated an enhanced the electrochemical activity due to the synergetic effect between SV-2 and GNSs, which significantly enhanced the reduction signal of NFT. Thereby, SVG-2/GCE has exhibited a good linear range (0.035–672.3 μM), good sensitivity (0.875 μA μA −1 cm −2 ) with a limit of detection (0.0087 μM). The anti-interference ability, good sensitivity, and operational stability were performed in the proposed electrode. The SVG-2 modified RRD electrode was capable of detecting NFT in blood serum and human urine samples in real-time monitoring analysis. These electrochemical tests were revealed an entirely new perspective on the electrocatalytic activity as well as outstanding amplification results at ultra-trace levels. Schematic illustration of the facile synthesis of SmVO 4 NPs anchored GNSs nanocomposites and their electrochemical application. • Samarium vanadate anchored graphene nanosheets nanocomposites was successfully prepared through ultrasonication. • The synergistic effect of SmVO 4 and GNSs enhanced electrochemical detection of nitrofurantoin. • The SVG sensor exhibited a higher linear range of 0.035–672.3 μM, low detection limit of 0.0087 μM towards nitrofurantoin detection. • The SVG-2 modified electrode were applied for NFT detection with acceptable operational stability, reproducibility, and real-time detection in biological fluids.

HELP (Hydrogen peroxide electrochemical profiling): A novel biosensor for measuring hydrogen peroxide levels expressed in breath for monitoring airway inflammation using electrochemical methods

Breathomics is being explored as a non-invasive pathway for disease diagnosis. In this paper we describe the design and fabrication of an electrochemical transduction-based sensing scheme that can be used for the non-invasive diagnosis of respiratory inflammation by monitoring hydrogen peroxide (H2O2) vapors in breath. AuNP-nafion@[BMIM]BF4 modified electrode forms the backbone of the electrochemical sensor platform. This is the first report of an electrochemical sensor platform for assessing airway inflammation by monitoring H2O2 levels in the lower parts-per billion (50 ppb) range. We engineered the RTIL interaction with the target analyte through computational and chemical modeling. The results obtained via computational and electrochemical modeling helped in strengthening our premise and serve as a proof-of-concept for the advancement of a breathomics-aided electrochemical detection approach.

Copper oxide-carboxylated graphene nanocrystals modified electrode for sensitive detection of glucose

A novel approach for electrochemical detection of glucose has been developed by flower-like copper oxide-carboxylated graphene (CuO-CG) nanocrystals modified electrode. The modified electrode was constructed by the electrodeposition method. CG and copper were successively electrodeposited on a bare glassy carbon electrode (GCE), and then CuO was formed in situ by electrochemical oxidization of the copper film to obtain the final CuO-CG-GCE. Electrocatalytic activity of the CuO-CG-GCE towards glucose oxidation was explored using cyclic voltammetry. The oxidation peak current of glucose obtained by CuO-CG-GCE was more than 130-fold higher than that of the bare GCE. The CuO-CG-GCE could detect glucose from 0.1 μM to 3.17 mM by chronoamperometry with a limit of detection of 10 nM, sensitivity of 1295 μA mM−1 cm−2, and response time of 1 ∼ 4 s. These results suggested that the CuO-CG nanocrystals could become promising electrode materials for electrochemical sensors.

Fully automated station for testing, characterizing and modifying screen-printed electrodes.

Electrochemical detection systems that provide either quantitative or sample-to-answer information are promising for various analytical applications in the emerging field of point-of-care testing (POCT). Nevertheless, in mobile POC systems optical detection is currently more preferred compared to electrochemical detection due to the insufficient robustness of electrochemical detection approaches toward "real world" use. Over the last couple of decades, screen-printed electrodes (SPEs) have emerged as a simple and low-cost electrochemical detection platform. Here, we report, firstly and solely, a novel benchtop system for the processing of electrochemical methods on SPE platforms. Our solution prevents operator errors from occurring while processing and testing SPEs, achieves an automatic processing of more than 300 electrodes per day and enables comparative testing due to the presence of two simultaneous working channels; furthermore, the SPEs used can be stored in specially-designed cartridges. This novel device helps to overcome the major disadvantages in processing SPE technology, such as a low level of automation and issues with process repeatability, making this technology more efficient and enabling faster growth in industry.

Development of an optical flow through detector for bubbles, crystals and particles in oils.

The characterisation of bubbles or particles in an oil poses some unique challenges. In contrast to water solutions, the use of electrochemical detection approaches is more difficult in an oil. However, optical sensing systems have considerable potential in this area. Here we use a flow through channel approach and monitor the light propagation through this structure in an optical transmission sensor arrangement (OTS). This simple approach is demonstrated to be useful at detecting bubbles produced in the oil as a result of cavitation induced by high intensity ultrasound (HIU). The optical technique is shown to have an analytical basis. Bubble detection from an operating HIU source is shown to depend on position of the sensor with respect to the source. Critically, the bubble population can be followed for extended time periods after the ultrasonic source has been terminated. The detection of crystals is also demonstrated. Hence, this technique is ideal for the study of the effects of HIU on oils as they crystallise over extended time periods.

Direct electrochemistry of silver nanoparticles-decorated metal-organic frameworks for telomerase activity sensing via allosteric activation of an aptamer hairpin

A direct electrochemistry of silver nanoparticles (AgNPs)-anchored metal-organic frameworks (MOFs) is developed for detection of telomerase activity based on allosteric activation of an aptamer hairpin. AgNPs in situ decorated on PCN-224 (AgNPs/PCN-224) constituted the direct electrochemical labels that were further biofunctionalized by recognition moiety of streptavidin (SA). To achieve the target biosensing, an allosteric hairpin-structured DNA was elaborately designed for signal transduction. The presence of telomerase elongated its primer in the hairpin to displace partial stem strand, thus resulted in the formation of SA aptamer-open structure. Through the specific interaction with aptamer, SA-biofunctionalized AgNPs/PCN-224 probe was attached onto the electrode surface, generating electrochemical signal at + 0.072 V of AgNPs centralized by MOF structure. The direct electrochemical biosensor showed target activity-dependent response from 1.0 × 10−7 to 1.0 × 10−1 IU L−1 with a detection limit of 5.4 × 10−8 IU L−1. Moreover, the sensor was applied in evaluation of telomerase activity in living cancer cells. The established electrochemical detection approach in this work avoids the critical deoxygenation conditions and additional electrocatalytic reagents, which opens a novel biosensing perspective for direct electrochemistry of MOF-based nanocomposites.

A reliable electrochemical approach for detection of sulphite with Tl-doped in Mn3O4 nanostructures and ionic liquid-modified carbon paste electrode

ABSTRACT In this work, we have designed and developed a new electrochemical sensing platform to determine sulphite, with the aid of a carbon paste electrode modified with thallium doped Mn3O4 nanostructures and ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate) (Tl-Mn3O4/IL/CPE). Electrochemical oxidation of sulphite at the Tl-Mn3O4/IL/CPE was investigated by the cyclic voltammetry (CV), linear sweep voltammetry (LSV), differential pulse voltammetry (DPV) and chronoamperometry (CHA) methods. The results of electrocatalytic activity proved that the Tl-Mn3O4/IL/CPE has electrocatalytic activity compared to unmodified CPE, Tl-Mn3O4/CPE and IL/CPE for sulphite oxidation. The experimental results showed the wide linearity range (0.03 to 235.0 μM) with lower value of detection (10.0 nM) for detection of sulphite. As expected, the proposed electrochemical sensor exhibits long time stability, excellent repeatability and reproducibility. In addition, this sensor exhibited high selectivity for the detection of sulphite in the presence of possible Interferences. The practical applicability of the modified electrode was examined in water samples with good recovery values. This facile and cost-effective method provides a novel strategy for monitoring of sulphite in real samples.

A biomimetic “intestinal microvillus” cell sensor based on 3D bioprinting for the detection of wheat allergen gliadin

A biomimetic “intestinal microvillus” electrochemical cell sensor based on three-dimensional (3D) bioprinting was developed, which can specifically and accurately detect wheat gliadin. Self-assembled flower-like copper oxide nanoparticles (FCONp) and hydrazide-functionalized multiwalled carbon nanotubes (MWCNT-CDH) were innovatively synthesized to improve the sensor performance. A conductive biocomposite hydrogel (bioink) was prepared by mixing FCONp and MWCNT-CDH based on GelMA gel. The cluster-shaped microvillus structure of small intestine was accurately printed on the screen printing electrode with the prepared bioink using stereolithography 3D-bioprinting technology, and then the Rat Basophilic Leukemia cells were immobilized on the gel skeleton. Next, the developed cell sensor was used to effectively detect wheat allergen gliadin. The experimental results show that the bioprinted cell sensor sensitively detects wheat gliadin when the optimized cell numbers and immobilized time are 1 × 106 cells/mL and 10 min, respectively. The linear detection range is 0.1–0.8 ng/mL, and the detection limit is 0.036 ng/mL. The electrochemical cell sensor based on 3D printing technology has excellent stability and reproducibility. Thus, a simple and novel electrochemical detection approach for food allergens was established in this study with potential application in food safety detection and evaluation.

Electrochemical Detection of 2-Nitrophenol Using a Glassy Carbon Electrode Modified with BaO Nanorods.

Here, an electrochemical detection approach (differential pulse voltammetry) was employed to develop a 2-nitrophenol (2-NP) sensor probe using a glassy carbon electrode (GCE) coated by wet-chemically synthesized nanorods (NRs) of BaO. The prepared BaO NRs were characterized by field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD) analysis. The peak currents by differential pulse voltammetric (DPV) analysis of 2-NP are plotted against the concentration to obtain the calibration curve of the 2-NP detection. It was found to be linear from 1.5 to 9.0 μM, defined as the dynamic range (LDR) for 2-NP detection in phosphate buffer solution. The sensor sensitivity was calculated from the slope of LDR by considering the active surface area of NRs coated on GCE (0.0316 cm2 ) and found as 17.6 μAμM-1 cm-2 . The limit of detection (LOD) was calculated as 0.50±0.025 μM from the signal/noise (S/N) ratio of 3. Moreover, the sensor analytical parameters such as reproducibility, long-term performing ability (stability), response time and validity in real environmental samples were found acceptable and to give satisfactory results. The development of a nanomaterial-based electrochemical chemical sensor might be an effective approach to sensor technology to detect carcinogenic and hazardous toxins for environmental safety and healthcare fields in a broad scale.

A reliable electrochemical approach for detection of testosterone with CuO-doped CeO2 nanocomposites-coated glassy carbon electrode

A reliable sensor for the detection of testosterone was developed by the deposition CuO/CeO2 nanocomposites (NCs) onto glassy carbon electrode (GCE). The wet chemically prepared NCs were totally characterized in detail by X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, and energy-dispersive X-ray spectroscopy analysis. In this electrochemical (I–V) approach, a current versus concentration of testosterone is plotted, which is known as calibration of testosterone sensor. It is obtained the linearly over the concentration range of 0.1 to 0.01 nM, which is denoted as a linear dynamic range (LDR). The sensor sensitivity is achieved from the slope of the calibration curve by considering the active surface area of GCE (0.0316 cm2), which is equal to 27.3576 µA µM−1 cm−2. The lower limit for the detection of testosterone is calculated (as 9.30 ± 0.47 pM) from signal–noise ratio at 3. Besides this, the response time, long-time performing stability, and reproducibility of sensor are found reliable and good. The biological samples such as human, mouse, and rabbit serums were tested for the validity of the proposed sensor probe to the selective detection.

Electrocatalytic reduction of 2, 6-dinitrophenol on polycongo red decorated glassy carbon electrode for sensing application

2, 6-dinitrophenol (2, 6-DNP) is a toxic chemical with significant negative impact on human health and ecosystem (aquatic lives). Hence, efficient monitoring of this pollutant is key in environmental management. Therefore, this study reported in-situ deposition of polycongo red (PCR) film by electrochemical approach for detection and monitoring of 2, 6-DNP. The synthesized PCR film was characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. Being a conductive polymer, PCR film electrocatalyzed reduction of 2, 6-DNP to 2, 6-diaminophenol. The synthesized PCR film displayed satisfactory response towards sensing of 2, 6-DNP with limit of detection (LOD) of 0.1 μM (S/N = 3) and linear range of 0.5 μM to 65 μM. Also, the responses of PCR film towards sensing of 2, 6-DNP was repeatable, reproducible, interference-free with short response time. Lastly, the proposed 2, 6-DNP sensor was satisfactorily used for detection of 2, 6-DNP in environmental real samples.

Magnetic Bead-Based Electrochemical Immunoassays On-Drop and On-Chip for Procalcitonin Determination: Disposable Tools for Clinical Sepsis Diagnosis.

Procalcitonin (PCT) is a known protein biomarker clinically used for the early stages of sepsis diagnosis and therapy guidance. For its reliable determination, sandwich format magnetic bead-based immunoassays with two different electrochemical detection approaches are described: (i) disposable screen-printed carbon electrodes (SPE-C, on-drop detection); (ii) electro-kinetically driven microfluidic chips with integrated Au electrodes (EMC-Au, on-chip detection). Both approaches exhibited enough sensitivity (limit of detection (LOD) of 0.1 and 0.04 ng mL−1 for SPE-C and EMC-Au, respectively; cutoff 0.5 ng mL−1), an adequate working range for the clinically relevant concentrations (0.5–1000 and 0.1–20 ng mL−1 for SPE-C and EMC-Au, respectively), and good precision (RSD < 9%), using low sample volumes (25 µL) with total assay times less than 20 min. The suitability of both approaches was successfully demonstrated by the analysis of human serum and plasma samples, for which good recoveries were obtained (89–120%). Furthermore, the EMC-Au approach enabled the easy automation of the process, constituting a reliable alternative diagnostic tool for on-site/bed-site clinical analysis.

Direct Detection and Discrimination of Nucleotide Polymorphisms Using Anthraquinone Labeled DNA Probes

A novel electrochemical detection approach using DNA probes labeled with Anthraquinone (AQ) as a reporter moiety has been successfully exploited as a method for the direct detection of DNA targets. This assay uses simple voltammetry techniques (Differential Pulse Voltammetry) to exploit the unique responsiveness of AQ to its chemical environments within oxygenated aqueous buffers, providing a specific detection mechanism as a result of DNA hybridization. This measurement is based on a cathodic shift of the reduction potential of the AQ tag and the concurrent reduction in peak current upon DNA binding. The further utility of this approach for discrimination of closely related DNA targets is demonstrated using DNA strands specific to B. anthracis and closely related bacillus species. DNA targets were designed to the rpoB gene incorporating nucleotide polymorphisms associated with different bacillus species. This assay was used to demonstrate that the shift in reduction potential is directly related to the homology of the target DNA. The discriminatory mechanism is dependent on the presence of oxygen in the measurement buffer and is strongly linked to the position of the nucleotide polymorphisms; with homology at the terminus carrying the AQ functionalised nucleotide critical to achieving accurate discrimination. This understanding of assay design was used to demonstrate an optimized assay capable of discriminating between Yersinia pestis (the causative agent of plague) and closely related species based on the groEL gene. This method is attractive as it can not only detect DNA binding, but can also discriminate between multiple Single Nucleotide Polymorphisms (SNPs) within that DNA without the need for any additional reagents, reporters, or processes such as melting of DNA strands. This indicates that this approach may have great potential to be exploited within novel biosensors for detection and diagnosis of infectious disease in future Point of Care (PoC) devices.

A new approach for electrochemical detection of organochlorine compound lindane: Development of molecular imprinting polymer with polyoxometalate/carbon nitride nanotubes composite and validation

Organochlorine compounds such as gamma-lindane (γ-LND) are very toxic and important ubiquitous contaminants in the environment. In this report, new molecular imprinted sensor on polyoxometalate (POM, H3PW12O40)/carbon nitride nanotubes (C3N4 NTs) composite were prepared for γ-LND detection. The structures of C3N4 NTs and H3PW12O40/C3N4 NTs composite were highlighted by scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDX), x ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). γ-LND imprinted electrode was prepared in the presence of 100.0 mM pyrrole containing 25.0 mM γ-LND. The analytical results have revealed that 1.0 × 10−10−1.0 × 10−8 M and 2.0 × 10−11 M were found as linearity range and the detection limit (LOD). Furthermore, the developed sensor was examined in terms of stability, repeatability, reproducibility and reusability. Finally, the imprinted sensor was applied to orange juice samples having high recovery.

Non-enzymatic electrochemical detection of uric acid with electrodeposited Nafion film

To eliminate the interference effect of ascorbic acid (AA) and reduced nicotinamide adenine dinucleotide (NADH) on electrochemical detection of uric acid (UA), a non-enzymatic approach for electrochemical detection of UA was developed using the Nafion-modified screen-printed carbon electrode strip (SPCEs). Electrodeposition was utilized to control the thickness of Nafion film. With Nafion-modified SPCEs, the selectivity of UA from AA and NADH was investigated. The Nafion-modified SPCEs exhibits high selectivity of UA, good linearity, and reasonable detection limit in neutral pH environment. The interference effect can be evidently reduced. The advantages are no requirements of enzyme reagents, acid environment, and complicated preparation of the electrodes.