elective determination of L-dopa in the presence of uric acid and ascorbic acid at a gold nanoparticle self-assembled carbon nanotube-modified pyrolytic graphite electrode
This document describes research on developing a gold nanoparticle-functionalized carbon nanotube (AuNP-CNT) modified pyrolytic graphite electrode (PGE) for selective determination of L-dopa in the presence of uric acid and ascorbic acid. The AuNP-CNT material was characterized using transmission electron microscopy and X-ray diffraction. Differential pulse voltammetry experiments showed that the AuNP-CNT/PGE had higher sensitivity for L-dopa oxidation compared to an unmodified PGE, with a linear response between 0.1-150 μM and a detection limit of 50 nM. The modified electrode was also able to effectively avoid interference from uric acid and ascorbic acid.
Study of electrical properties of Polythiophene and its compositesIOSR Journals
Conducting polymers are known to have significant electrical properties which can be improved by strong oxidizing power of oxidizing agents like V2O5. In the current study oxidative polymerization of the thiophene monomers was done to obtain Polythiophene for converting it into its composites with V2O5 to study their improved electrical nature. The electrical properties of pure Polythiophene, pure V2O5, PTh- V2O5 composite 1:2 (thiophene: V2O5) and PTh- V2O5 composite 2:1(thiophene: V2O5) were studied by carrying out current voltage measurements. It can be stated that the increased concentration of V2O5 is responsible for the increased current flow through the polymer matrix. The study is explained on the basis of fact that oxidizing power leads to removal of higher number of charge carriers from the backbone thereby causing increases in current flow. Such conducting polymers have wide range of applications in the field of Metal ions detectors, molecular electronics, conductive adhesive, electrical displays, electromagnetic shields, chemical, biochemical and thermal sensors, rechargeable batteries, solid electrolytes, optical computers and ion exchange membrane
Electro catalytic performance of pt-supported poly (o-phenylenediamine) micro...sunitha81
Poly (o-phenylenediamine) (PoPD) microrods were obtained by interfacial
polymerization using ferric chloride as oxidant and without any template or
functional dopant. Pt/PoPD nanocatalysts were prepared by the reduction of chloroplatinic
acid with sodium borohydride, and the composite catalysts formed were
characterized by X-ray diffraction and electrochemical methods. The nanocomposite
of Pt/PoPD microrods has been explored for their electro-catalytic performance
towards oxidation of methanol. The electro-catalytic activity of Pt/PoPD was
found to be much higher (current density 1.96 mA/cm2 at 0.70 V) in comparison to
Pt/Vulcan electrodes (the current density values of 1.56 mA/cm2 at 0.71 V) which
may be attributed to the microrod morphology of PoPD that facilitate the effective
dispersion of Pt particles and easier access of methanol towards the catalytic sites.
IOSR Journal of Applied Chemistry (IOSR-JAC) is an open access international journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Polyaniline (PANI) Metal Oxide Nano Composites as a Conducting MaterialRSIS International
The combination of conducting nanoparticles and conducting polymers is a new area of research. The conducting polymer nanocomposites have both advantages of low dimensional systems and organic conductors. With this nanofibre morphology, the dispersibility and processibility of polyanilines can be improved.
The aim of this literature is to provide a survey of previous findings of researchers related to metal oxide nanocomposite polyaniline. In this paper we reviewed the properties, methods of synthesis, and various applications.
Study of electrical properties of Polythiophene and its compositesIOSR Journals
Conducting polymers are known to have significant electrical properties which can be improved by strong oxidizing power of oxidizing agents like V2O5. In the current study oxidative polymerization of the thiophene monomers was done to obtain Polythiophene for converting it into its composites with V2O5 to study their improved electrical nature. The electrical properties of pure Polythiophene, pure V2O5, PTh- V2O5 composite 1:2 (thiophene: V2O5) and PTh- V2O5 composite 2:1(thiophene: V2O5) were studied by carrying out current voltage measurements. It can be stated that the increased concentration of V2O5 is responsible for the increased current flow through the polymer matrix. The study is explained on the basis of fact that oxidizing power leads to removal of higher number of charge carriers from the backbone thereby causing increases in current flow. Such conducting polymers have wide range of applications in the field of Metal ions detectors, molecular electronics, conductive adhesive, electrical displays, electromagnetic shields, chemical, biochemical and thermal sensors, rechargeable batteries, solid electrolytes, optical computers and ion exchange membrane
Electro catalytic performance of pt-supported poly (o-phenylenediamine) micro...sunitha81
Poly (o-phenylenediamine) (PoPD) microrods were obtained by interfacial
polymerization using ferric chloride as oxidant and without any template or
functional dopant. Pt/PoPD nanocatalysts were prepared by the reduction of chloroplatinic
acid with sodium borohydride, and the composite catalysts formed were
characterized by X-ray diffraction and electrochemical methods. The nanocomposite
of Pt/PoPD microrods has been explored for their electro-catalytic performance
towards oxidation of methanol. The electro-catalytic activity of Pt/PoPD was
found to be much higher (current density 1.96 mA/cm2 at 0.70 V) in comparison to
Pt/Vulcan electrodes (the current density values of 1.56 mA/cm2 at 0.71 V) which
may be attributed to the microrod morphology of PoPD that facilitate the effective
dispersion of Pt particles and easier access of methanol towards the catalytic sites.
IOSR Journal of Applied Chemistry (IOSR-JAC) is an open access international journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Polyaniline (PANI) Metal Oxide Nano Composites as a Conducting MaterialRSIS International
The combination of conducting nanoparticles and conducting polymers is a new area of research. The conducting polymer nanocomposites have both advantages of low dimensional systems and organic conductors. With this nanofibre morphology, the dispersibility and processibility of polyanilines can be improved.
The aim of this literature is to provide a survey of previous findings of researchers related to metal oxide nanocomposite polyaniline. In this paper we reviewed the properties, methods of synthesis, and various applications.
Fullerene Functionalized Thiophene Derivative as an Acceptor Material for Org...CrimsonPublishersRDMS
Fullerene Functionalized Thiophene Derivative as an Acceptor Material for Organic Photovoltaics by Ranjith Kottokkaran* in Research & Development in Material Science
A Suspected Derivative Morphology for pheophytin (脫鎂葉綠素) and the Enhanced H...cclarbl
● What’s the role of pheophytin (pheo) in photosynthesis?
● What might be pheo’s other structure-related roles? → things we bumped into in the original low-power chlorophyll battery
●. Porphyrin-ring family and their uses
●. A conjectured derivative morphology and associated proton conduction path within pheophytins (pheo’s)
● Spectral comparison among: 1st-principle quantum simulation, measurement on ethanol-extracted pheo, and existing literature
● Experimental evidence in pheo-catalyzed decomposition of hydrogen gas
● Summary and conclusions
SIMONA CAVALU_Raman and Surface Enhanced Raman Spectroscopy of 2,2,5,5-Tetram...Simona Cavalu
ABSTRACT: 2,2,5,5-Tetramethyl-3-pyrrolin-1-yloxy-3-carboxamide (tempyo) labeled bovine
serum albumin and cytochrome c at different pH values were prepared and
investigated using Raman–resonance Raman (RR) spectroscopy and surface enhanced
Raman scattering (SERS) spectroscopy. The Raman spectra of tempyo labeled proteins
in the pH 6.7–11 range were compared to those of the corresponding free species. The
SERS spectra were interpreted in terms of the structural changes of the tempyo labeled
proteins adsorbed on the silver colloidal surface. The tempyo spin label was found to be
inactive in the Raman–RR and SERS spectra of the proteins. The a-helix conformation
was concluded to be more favorable as the SERS binding site of bovine serumalbumin.
In the cytochrome c the enhancement of the bands assigned to the porphyrin macrocycle
stretching mode allowed the supposition of the N-adsorption onto the colloidal surface.
New Schiff base ligand (E)-6-(2-(4-
(dimethylamino)benzylideneamino)-2-phenylacetamido)-3,3-
dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic
acid = (HL) Figure(1) was prepared via condensation of
Ampicillin and 4(dimethylamino)benzaldehyde in methanol
.Polydentate mixed ligand complexes were obtained from 1:1:2
molar ratio reactions with metal ions and HL, 2NA on reaction
with MCl2 .nH2O salt yields complexes corresponding to the
formulas [M(L)(NA)2Cl] ,where M =
Fe(II),Co(II),Ni(II),Cu(II),and Zn(II) and NA=nicotinamide.
The 1H-NMR, FT-IR, UV-Vis and elemental analysis
were used for the characterization of the ligand. The complexes
were structurally studied through AAS, FT-IR, UV-Vis,
chloride contents, conductance, and magnetic susceptibility
measurements. All complexes are non-electrolytes in DMSO
solution. Octahedral geometries have been suggested for each
of the complexes. The Schiff base ligands function as
tridentates and the deprotonated enolic form is preferred for
coordination. In order to evaluate the effect of the bactericidal
activity, these synthesized complexes, in comparison to the un
complexed Schiff base has been screened against bacterial
species, Staphy
Synthesis and properties of PolyanilineAwad Albalwi
Polyaniline which is regarding kind of Inherently Conducting Polymers (ICPs), was prepared by
either chemical and electricchemical polymerization in acidic medium. Such solvents were used
and compared the affecting on the conductivity between EB solution in DMF and mcresol solvents by using UVvis spectrum. UVvis
spectra and cyclic voltametry were used to generate
and analyze the spectrum for the polymer films
Follow-up a 11 anni delle lesione post-traumatiche dell'aorta toracica: effic...Benedetto Gesmundo
Tesi di laurea in medicina e chirurgia:
"Follow-up a 11 anni delle lesione post-traumatiche dell'aorta toracica: efficacy and effectiveness del trattamento a lungo termine"
Fullerene Functionalized Thiophene Derivative as an Acceptor Material for Org...CrimsonPublishersRDMS
Fullerene Functionalized Thiophene Derivative as an Acceptor Material for Organic Photovoltaics by Ranjith Kottokkaran* in Research & Development in Material Science
A Suspected Derivative Morphology for pheophytin (脫鎂葉綠素) and the Enhanced H...cclarbl
● What’s the role of pheophytin (pheo) in photosynthesis?
● What might be pheo’s other structure-related roles? → things we bumped into in the original low-power chlorophyll battery
●. Porphyrin-ring family and their uses
●. A conjectured derivative morphology and associated proton conduction path within pheophytins (pheo’s)
● Spectral comparison among: 1st-principle quantum simulation, measurement on ethanol-extracted pheo, and existing literature
● Experimental evidence in pheo-catalyzed decomposition of hydrogen gas
● Summary and conclusions
SIMONA CAVALU_Raman and Surface Enhanced Raman Spectroscopy of 2,2,5,5-Tetram...Simona Cavalu
ABSTRACT: 2,2,5,5-Tetramethyl-3-pyrrolin-1-yloxy-3-carboxamide (tempyo) labeled bovine
serum albumin and cytochrome c at different pH values were prepared and
investigated using Raman–resonance Raman (RR) spectroscopy and surface enhanced
Raman scattering (SERS) spectroscopy. The Raman spectra of tempyo labeled proteins
in the pH 6.7–11 range were compared to those of the corresponding free species. The
SERS spectra were interpreted in terms of the structural changes of the tempyo labeled
proteins adsorbed on the silver colloidal surface. The tempyo spin label was found to be
inactive in the Raman–RR and SERS spectra of the proteins. The a-helix conformation
was concluded to be more favorable as the SERS binding site of bovine serumalbumin.
In the cytochrome c the enhancement of the bands assigned to the porphyrin macrocycle
stretching mode allowed the supposition of the N-adsorption onto the colloidal surface.
New Schiff base ligand (E)-6-(2-(4-
(dimethylamino)benzylideneamino)-2-phenylacetamido)-3,3-
dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic
acid = (HL) Figure(1) was prepared via condensation of
Ampicillin and 4(dimethylamino)benzaldehyde in methanol
.Polydentate mixed ligand complexes were obtained from 1:1:2
molar ratio reactions with metal ions and HL, 2NA on reaction
with MCl2 .nH2O salt yields complexes corresponding to the
formulas [M(L)(NA)2Cl] ,where M =
Fe(II),Co(II),Ni(II),Cu(II),and Zn(II) and NA=nicotinamide.
The 1H-NMR, FT-IR, UV-Vis and elemental analysis
were used for the characterization of the ligand. The complexes
were structurally studied through AAS, FT-IR, UV-Vis,
chloride contents, conductance, and magnetic susceptibility
measurements. All complexes are non-electrolytes in DMSO
solution. Octahedral geometries have been suggested for each
of the complexes. The Schiff base ligands function as
tridentates and the deprotonated enolic form is preferred for
coordination. In order to evaluate the effect of the bactericidal
activity, these synthesized complexes, in comparison to the un
complexed Schiff base has been screened against bacterial
species, Staphy
Synthesis and properties of PolyanilineAwad Albalwi
Polyaniline which is regarding kind of Inherently Conducting Polymers (ICPs), was prepared by
either chemical and electricchemical polymerization in acidic medium. Such solvents were used
and compared the affecting on the conductivity between EB solution in DMF and mcresol solvents by using UVvis spectrum. UVvis
spectra and cyclic voltametry were used to generate
and analyze the spectrum for the polymer films
Follow-up a 11 anni delle lesione post-traumatiche dell'aorta toracica: effic...Benedetto Gesmundo
Tesi di laurea in medicina e chirurgia:
"Follow-up a 11 anni delle lesione post-traumatiche dell'aorta toracica: efficacy and effectiveness del trattamento a lungo termine"
Similar to elective determination of L-dopa in the presence of uric acid and ascorbic acid at a gold nanoparticle self-assembled carbon nanotube-modified pyrolytic graphite electrode
IOSR Journal of Applied Chemistry (IOSR-JAC) is an open access international journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Electrochemical behaviorof carbon paste electrode modified with Carbon Nanofi...IJERA Editor
The electrochemical behavior of carbon paste electrode modified with carbon nanofibers has been studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scaning electron microscopy. The response of modified electrodein ferroferricyanidesolutionshows reversible behavior and significant increment in current value compared to the bare CPE indicating that CNFs act as efficient electron mediator to catalyze reactions at the surface. The modified electrode has been used to study the electrochemical response of bisphenol Ausing different electrochemical techniques such as cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry and square wave voltammetry. The oxidation peak of BPA was observed at about 0.53 V in phosphate buffer solution at pH 6.7. The oxidation peak current of BPA varied linearly with concentration over a wide range of 5µmol L-1 to 400 µmol L-1 and the detection limit of this method was found to be 0.55 µmol L
Oxidized multi walled carbon nanotubes for improving the electrocatalytic act...Iranian Chemical Society
In the present paper, the use of a novel carbon paste electrode modified by 7,8-dihydroxy-3,3,6-trimethyl-3,4-dihydrodibenzo[b,d]furan-1(2H)-one (DTD) and oxidized multi-walled carbon nanotubes (OCNTs) is described for determination of levodopa (LD), acetaminophen (AC) and tryptophan (Trp) by a simple and rapid method. At first, the electrochemical behavior of DTD is studied, then, the mediated oxidation of LD at the modified electrode is investigated. At the optimum pH of 7.4, the oxidation of LD occurs at a potential about 330 mV less positive than that of an unmodified carbon paste electrode. Based on differential pulse voltammetry (DPV), the oxidation current of LD exhibits a linear range between 1.0 and 2000.0 μM of LD with a detection limit (3σ) of 0.36 μM. DPV was also used for simultaneous determination of LD, AC and Trp at the modified electrode. Finally, the proposed electrochemical sensor was used for determinations of these substances in human serum sample.
A protamine-conjugated gold decorated graphene oxide composite as an electroc...Arun kumar
In this study, an effective electrochemical sensor was developed for heparin detection using a protamineconjugated
graphene oxide/gold (GO/Au) composite. Protamine is an antidote that can act as an affinity ligand
for heparin. The GO was used as support for signal amplification, and Au nanoparticles (NPs) were employed
to immobilize the protamine. This Au NPs also increasing the electron transfer rate and enhancing the signal response
during protamine-heparin integration. The proposed affinity sensor had a simple fabrication process, a
low detection limit (0.9 nM), a wide linear range (1.9 × 10−7 M to 1.5 × 10−9 M), high stability, and high selectivity
in the detection of heparin.
Novel composite electrodes:Preparation and application to the electroanalytic...Université de Dschang
M. Tchieno Melataguia Francis Merlin a soutenu une thèse de Doctorat/Phd en Chimie Inorganique ce 06 juin 2016 dans la salle des conférences de l'Université de Dschang. A l'issue de cette soutenance devant le jury présidé par le Prof. Emmanuel Ngameni lui a décerné la mention très honorable à l'unanimité de ses membres.
An ideal I.S.E. consists of a thin membrane across which only the
intended ion can be transported.
The transport of ions from a high conc. to a low one through a selective binding with some sites within the membrane creates a
A new technique to measure oxygen reduction kinetics underneath coatings using hydrogen permeation from the back side. Huge step towards characterising buried interface reactivity.
Nanostructured fe2 o3 platform for the electrochemical sensing of folic acidtshankar20134
Similar to elective determination of L-dopa in the presence of uric acid and ascorbic acid at a gold nanoparticle self-assembled carbon nanotube-modified pyrolytic graphite electrode (20)
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
FIDO Alliance Osaka Seminar: Passkeys and the Road Ahead.pdf
elective determination of L-dopa in the presence of uric acid and ascorbic acid at a gold nanoparticle self-assembled carbon nanotube-modified pyrolytic graphite electrode
2. 4712 G. Hu et al. / Electrochimica Acta 55 (2010) 4711–4716
electrochemical determination of biomolecules and drugs, e.g. dex-
amethasone [19], triamcinolone [20], 2 ,3 -dideoxyadenosine [21],
adenosine and guanosine [22], paracetamol [23], uric acid [24],
dopamine [25] and inosine [26]. Yan et al. proved that single-wall
carbon nanotubes can effectively decrease the oxidation poten-
tial of L-dopa and can be utilized to prepare a single-wall carbon
nanotube-modified glassy carbon electrode for the determination
of L-dopa, with a detection limit of about 0.3 M [27]. Xiang et
al. reported a multi-wall carbon nanotubes-Nafion modified glassy
carbon electrode for the adsorption stripping voltammetry of L-
dopa, with a detection limit of about 50 nM [28]. Mathiyarasu and
Nyholm constructed a poly-(3,4-ethylenedioxythiophene)-single-
walled carbon nanotube composite-modified microelectrode and
applied it to the electrochemical determination of L-dopa, with a
detection limit of 0.1 M [29]. Shahrokhian and Asadian reported
a glassy carbon electrode modified by a bilayer of multi-walled
carbon nanotube and poly-pyrrole doped with tiron for the elec-
trochemical determination of L-dopa in the presence of AA, with a
detection limit of 0.1 M [30].
It is a fact that gold nanoparticles show good electrocat-
alytic activity towards the electrochemical oxidation of dopamine
[31–33]. In this paper, we have synthesized gold nanoparticle-
functionalized multi-wall carbon nanotubes by a self-assembly
method. The new material was applied to investigate the electro-
chemical behavior of L-dopa in neutral phosphate buffer solution
(PBS). Experimental data show that the proposed electrode can
effectively decrease the oxidation potential of L-dopa. Using the
differential pulse voltammetry for the accurate determination of L-
dopa, the oxidation current is proportional with its concentration
in the range of 0.1–150 M, with a detection limit about 50 nM.
Meanwhile, the proposed sensor can also effectively avoid the
interference of AA and UA and has been successfully applied to
the determination of L-dopa formulations with high sensitivity and
good selectivity.
2. Experimental
2.1. Chemicals
Chloroauric acid and L-dopa hydrochloride were purchased
from the Sinopharm Chemical Reagent Co. (Shanghai, China). Ben-
zyl Mercaptan (BM), uric acid and ascorbic acid were purchased
from Alfa-Aesar (Tianjin, China). L-dopa capsules were purchased
from the Shanghai Roche Pharmaceuticals (Shanghai, China). All
other chemicals are of analytical grade and used as received.
Fig. 1. Preparation scheme of AuNP-CNTs.
3. G. Hu et al. / Electrochimica Acta 55 (2010) 4711–4716 4713
2.2. Synthesis of AuNP-CNTs
High-quality multi-wall carbon nanotubes were synthesized by
chemical vapor deposition method using Co/La2O3 as catalyst and
ethylene as carbon source in a tubular quartz reactor. The detailed
experimental procedure is given in our previous report [34]. Gold
nanoparticles were synthesized according to the former literature
[35]. The synthesis procedure of gold nanoparticles self-assembled
CNTs, illustrated as in Fig. 1, was similar to our previous report
[36]. Briefly, the obtained Au colloidal solution was added into
a toluene solution containing Benzyl Mercaptan (BM) and given
a stirring for 1 h, and then equal volume of distilled water was
added to the solution. A liquid in two phases was obtained. The
upper dark brown solution was BM-modified Au/toluene solution
and was washed with distilled water to remove the ethanol com-
pletely. About 33 mg of multi-walled CNTs was added to a certain
volume of toluene and given an ultrasonication for about 2 h to form
a CNTs/toluene suspension. The as-prepared suspension was mixed
with the above-mentioned BM-modified Au/toluene solution and
ultrasonicated for 12 h until all Au nanoparticles were anchored on
CNTs. The AuNP-CNT was separated from the mixture via suction
filtration and then washed by ethanol completely.
2.3. Preparation of AuNP-CNTs/PGE
Bare PGE (2 mm in diameter, Tianjin Aidahensheng Co., China)
was carefully polished with 1.0, 0.3, and 0.05 m alumina powders
in series, and then treated with 50% nitric acid, ethanol and water in
Fig. 2. TEM image (A) and XRD pattern (B) of Au-CNTs. (A, inset): SAED image of
Au-CNTs.
an ultrasonic bath, respectively. 10 mg of AuNP-CNTs were added
to 10 mL of N,N-dimethylformamide (DMF) under ultrasonic agita-
tion to give a black suspension. The AuNP-CNT/PGE was prepared
by casting 10 L of AuNP-CNT suspension on the pretreated PGE
surface and dried under an infrared lamp.
2.4. Measurements
The morphology of the Au-CNT nanocomposite was determined
with a JEOL 2010 TEM (JEOL, Japan) equipped with a LaB6 fila-
ment at 200 kV and an energy dispersive X-ray analyzer (EDAX,
USA). XRD data was obtained by an X’Pert PRO Multi-purpose
Diffractometer (PANalytical, Netherlands) using Cu K␣ radiation
(k = 0.15418 nm).
Voltammetric measurements were carried out on a CHI660C
electrochemical workstation (CHI Instrument, Shanghai). All mea-
surements were performed in a conventional three-electrode cell,
consisting of an unmodified PGE (Tianjin Aidahengsheng Technol-
ogy Co., China) or the AuNP-CNT-modified PGE working electrode,
a saturated calomel electrode (SCE) reference and a platinum wire
counter electrode. 0.1 M phosphate buffer solution at pH 6.9 was
prepared from KH2PO4 and K2HPO4 and its pH was adjusted value
with 1 M H2SO4 or NaOH solution. Prior to each electrochemical
measurement, the electrolyte solution was deoxygenated by bub-
bling with high-pure nitrogen for 30 min.
Fig. 3. (A) Cyclic voltagramms of AuNP-CNT/PGE (curve a and c) and CNT/PGE (curve
b) in the absence (curve a) and presence (curve b and c) of 20 M L-dopa in 0.1 M
PBS at pH 7.0, inset is CV curves of bare PGE in 0.1 M PBS at pH 7.0 without (curve
d) and with (curve e) 20 M L-dopa; (B) cyclic voltagramms of AuNP-CNT/PGE in
0.1 M PBS (pH 7.0) containing 20 M L-dopa at different scanning rate: a → j, 20, 40,
60, 80, 100, 120, 140, 160, 180, and 200 mV/s.
4. 4714 G. Hu et al. / Electrochimica Acta 55 (2010) 4711–4716
3. Results and discussion
3.1. Characterization of AuNP-CNTs
Fig. 2A presents a typical TEM image of the as-prepared
AuNP-CNTs. The spherical gold nanoparticles are homogenously
dispersed on CNTs without significant aggregation and the diam-
eter of them is from 5 to 10 nm. No dissociated Au nanoparticle
is observed on the background of TEM image, indicating that
these Au nanoparticles are strongly adhered on the CNT surface.
The selected area electron diffraction (SAED) pattern in Fig. 1
(inset) shows that these Au nanoparticles on CNT surface are poly-
crystalline structure. XRD pattern of AuNP-CNTs shows (0 0 2),
(1 0 1) and (0 0 4) reflections of graphite, as well as (0 0 2), (2 0 0),
(2 2 0) and (3 1 1) reflections of gold, indicating that metallic Au
phase exists in the as-prepared nanoscale hybrid. According to the
Scherrer equation [37], the average diameter of the gold nanopar-
ticles was calculated about 9.5 nm, consistent with previous TEM
results.
3.2. Electrochemical behavior of L-dopa
The electrochemical behavior of L-dopa was investigated with
cyclic voltammetry (CV) in 0.1 M phosphate buffer solution at pH
6.9. As shown in Fig. 3A (inset), a weak response and low elec-
tron transaction for L-dopa is observed on a bare PGE. A broad
oxidation peak of L-dopa is at 0.486 V, with a broad potential
region from 0.2 to 0.6 V. The CNT-modified PGE show a good
electrocatalytic oxidation towards L-dopa (as seen in Fig. 3A),
indicating that the CNT-modified PGE can effectively decrease
the oxidation potential of L-dopa to 0.196 V. However, a pair of
well-defined redox peaks is observed at the AuNP-CNT/PGE. The
anodic and cathodic peak potentials are at 0.212 and 0.173 V,
respectively, with a peak-to-peak separation of about 0.039 V.
Furthermore, the oxidation peak current (Ipa) of L-dopa at the
AuNP-CNT/PGE is 28.3- and 1.67-fold higher than that of the
bare and CNT-modified PG electrodes, with a better reversibility.
These results confirm that the Au nanoparticles on CNT surface
can effectively accelerate the electrochemical redox of L-dopa and
significantly increase the oxidation current at the modified elec-
trode.
The relationship between redox peaks current is also
investigated with CV method. The anodic and cathodic
currents are linear with the square root of the scan
rate from 20 to 200 mV s−1. The linear progress equa-
tion are Ipa(10−6 A) = (2.905 ± 1.112) + (0.307 ± 0.009) and
Ipc(10−6 A) = (10.370 ± 1.206) − (0.285 ± 0.009) (mV s−1), a corre-
lation coefficient of 0.997 and 0.996, respectively, indicating that
the electrode progress is controlled by adsorption [38]. The most
probable reason is that the electronegative oxygen-containing
groups and gold nanoparticles on CNTs surface can easily adsorb
electropositive L-dopa molecule in neutral PBS blank.
3.3. Effects of solution pH
Cyclic voltammetry was carried out to characterize the effects
of solution pH on redox peak potentials of L-dopa at the AuNP-
CNTs/PGE in Fig. 4. As shown in Fig. 4A, the redox peak potential
of L-dopa shifts negatively with the increase of solution pH, indi-
cating that protons take part in the electrode reaction process.
The anodic peak potential of L-dopa is proportional with the solu-
tion pH in the range of 3–10. The linear regression equation was
Epa(V) = (0.606 ± 0.014) − (0.057 ± 0.001)pH, with the correlation
coefficient 0.999, demonstrating that the electrode process is equal
proton-electron transfer. The slope of the equation is in close agree-
ment with the former report [27]. For a reversible electrochemical
Fig. 4. (A) CV curves of CNT/PGE in 0.1 M PBS containing 20 M L-dopa at different
pH: a → e, 3.3, 5.9, 7.0, 7.8, and 9.8; (B) dependence of anodic peak potential (black
triangle) and anodic peak current (green globular) as a function of solution pH in
0.1 M PBS containing 20 M L-dopa. (For interpretation of the references to color in
this figure legend, the reader is referred to the web version of the article.)
reaction, |Ep − Ep/2| = 59/n mV, the electron transfer number was
calculated to be 1.843 (approximately 2). So the electrochemical
redox of L-dopa at the proposed electrode is a two-electron coupled
two-proton transfer mechanism. Therefore, the electrochemical
redox process of L-dopa can be described as follows:
3.4. Effect of accumulation time
As the electrode progress is controlled by the adsorption of L-
dopa, it is very import to investigate the effects of accumulation
time. As shown in Fig. 5, the oxidation peak current of L-dopa
gradually increased with increasing accumulation time from 0 to
180 s, and reached the maximum current response at 180 s. Further
increasing the accumulation time, there is no significant increase in
the current response. This phenomenon is probably due to the sat-
urated adsorption of L-dopa on the AuNP-CNT/PGE surface, and no
change is observed when increasing the accumulation time. Herein,
180 s is chosen as the optimum accumulation time. The accumula-
tion potential was also investigated in the range of −0.4 to 0.1 V.
The results prove that varying accumulation potential does not
show sufficient influence on the increase of L-dopa oxidation cur-
rent. Therefore, a stirred accumulation for 180 s under open-circuit
was used for the preconcentration of L-dopa in each voltammetric
measurement.
5. G. Hu et al. / Electrochimica Acta 55 (2010) 4711–4716 4715
Fig. 5. Effect of accumulation time on peak current of 10 M L-dopa at AuNP-
CNT/PGE in 0.1 M PBS at pH 7.0.
3.5. DPV determination of L-dopa
Differential pulse voltammetry (DPV) method is normally used
for the determination of catecholamine compounds because of
its high sensitivity [39,40]. Herein, the determination of L-dopa
was also performed with the DPV method using the proposed
AuNP-CNT/PGE. Fig. 6 shows the DPV curves at different concen-
trations of L-dopa at the modified electrode. Clearly, the anodic
peak current increases linearly with L-dopa concentration rang-
ing from 0.1 to 150 M, the linear regress progression is IpL-dopa
(A) = (0.388 ± 0.596) + (1.073 ± 0.011) (M), with a correlation
coefficient of 0.998. The detection limit is 50 nM (S/N = 3), which is
better than that of the latest reports [30,41,42]. The relative stan-
dard deviation of 10 determinations for 10 M is 0.93%, showing
the good reproducibility of the proposed electrode. The anodic cur-
rent of L-dopa has no significant change at the proposed electrode
after its preparation for 2 months, indicating the excellent stability
of Au-CNT/PGE.
3.6. Interference study
It is well known that UA and AA are electroactive molecules
that coexist in a biological system [43], and that they can also
be oxidized in most conventional solid electrodes. Therefore, it is
Fig. 6. DPV curves of Au-CNT/PGE in 0.1 M PBS (pH 7.0) containing different con-
centration L-dopa: a → j, 0, 1, 4.5, 7.5, 15, 35, 50, 70, 90, and 100 M. Inset is the
linear relationship between Ipa and L-dopa concentration.
Fig. 7. CV curves of the Au-CNT/PGE (black line) by successively adding 1.0 mM AA
(red line), 20 M L-dopa (green line) and 20 M UA (blue line) in 0.1 M PBS at pH
7.0. (For interpretation of the references to color in this figure legend, the reader is
referred to the web version of the article.)
Table 1
Determination of L-dopa in capsules (n = 5).
Sample No. Labeled (mg) Detected (mg) RSD Recovery Bias (%)
1 200 196 ± 3 1.53% 98% −2.0
2 200 206 ± 5 1.84% 103% +3.0
3 200 203 ± 4 1.74% 102% +1.5
important to investigate these interferences in order to conduct
the accurate determination of L-dopa. Fig. 7 shows three individ-
ual anodic peaks appearing at the potential of −0.037, 0.208 and
0.336 V, which correspond to the oxidations of, AA, L-dopa and UA,
respectively. The results illustrate that the coexistence of UA and
AA has no influence on L-dopa determination. Equivalent amount of
dopamine and epinephrine will seriously affect the accurate deter-
mination of L-dopa. As their concentration in human blood and
urine is extremely low, so dopamine and epinephrine do not affect
the determination of L-dopa in human fluids. The influence of other
substances on L-dopa peak currents was also investigated, and no
interference was found for 10 M L-dopa in the presence of the
following substances: 100-fold glucose, urea and 1000-fold NO3
−,
Cl−, PO4
3−, SO4
2−, NH4
+, K+, Na+, Mg2+, Ca2+, with a deviation below
5%.
3.7. Sample analysis
In order to evaluate the validity of the proposed method, con-
tents of 30 hard capsules were emptied, weighed and carefully
mixed. A portion of the powder equivalent to 500 mg L-dopa
was accurately weighed, dissolved into 10 mL of 0.1 M H2SO4 and
separated with a centrifugal machine. Further dilution was also per-
formed with 0.1 M H2SO4 to reach the calibration range of L-dopa.
A standard addition was used for L-dopa concentration determina-
tion in 0.1 M PBS at pH 7.0. The recoveries were 98–103%, with
a relative standard deviation (RSD) lower than 2% (in Table 1),
confirming that the proposed sensor is reliable for L-dopa deter-
mination in pharmaceutical preparations.
4. Conclusions
High-quality gold nanoparticle-functionalized carbon nanotube
material has been successfully synthesized via self-assembly tech-
nology. The new material can be considered as a high sensitive and
selective sensor in voltammetric determination of L-dopa. The pro-
posed sensor shows a novel electrocatalytic activity towards the
6. 4716 G. Hu et al. / Electrochimica Acta 55 (2010) 4711–4716
anodic oxidation of L-dopa with a significant enlargement in peak
current and a great decrease in peak potential. The reproducibility,
good selectivity and stability, low detection limit of the proposed
electrode make it appropriate for use in the electrochemical deter-
mination of L-dopa in pharmaceutical and clinical preparations.
Acknowledgements
The authors thank the financial support of National Natural Sci-
ence Foundation of China (No. 20672121) and the open fund of State
Key Laboratory of Oxo Synthesis & Selective Oxidation (Grant No.
OSSO2008kjk6).
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