Science topics: ChemistryElectrochemistryElectrochemical Detection
Electrochemical Detection - Science topic
Explore the latest questions and answers in Electrochemical Detection, and find Electrochemical Detection experts.
Questions related to Electrochemical Detection
Why lead oxide nanoparticles cannot be used in electrochemical detection of heavy metals? Although it can be envisaged as suitable anodes for decontamination of waters containing organic polluants.
I wanna calculate the efficiency of an electrochemical detection of heavy metal ion using SWASV
I'm looking for Laviron's equation for adsorption controlled process, could anyone help me?
If I use TiO2 sensors for quantification of organic matter in a matrix where quantification using this photocatalytic substance has not been tested, would this be a good topic for an article? I know there are many articles on the use of TiO2 for sensing applications, and obviously this is not a recent topic. But are these sensors still a good option and a valuable research topic?
I use gold ultramicroelectrode (~ 10 um * 10 um) as working electrode. After electrochemical polishing, 2 uM haipin probe (3'- HS-SH-C6-CGCCAATATTTATGGCA - MB -5' TCEP reduction) was droped into the surface of ultramicroelectrode. Incubate at 4 ℃ overnight. After washing with deionized water, three-electrode mode was used to detect the MB signal in PBS by using SWV method. But I can get stable signal.
I am giving potential to my sample which is anodic region from -1000mV to 200mV, and i get a current response both having positive and negative sign..
I am confused about current flow, as per my understanding current need to flow in one direction as this potential range which i am applying is anodically active region. Then why current change its sign??
When using the modifiedcarbon paste electrode (CPE) for electrochemical detection, most of the time the response is weak, how can we improve the response?
I think that one of the main factors is the used paraffin oil? What do you think of this?
I'm working on electrochemical sensing drug molecule. My workstation is Origalys (origaflex 500). In papersa particular concentration is reported for every sensing studies like 200micromolar etc. How to do chronoamperometry for the sensing application and what is the relevance of this concentration. How to get this value of concentration
Please share your ideas
Ferrocene (Fc) has been regarded as a helpful catalyst for the electro-oxidation of dopamine, ascorbic acid, Levodopa, etc., at different potentials.
If anyone suggests to me any literature about why ferrocene works as a catalyst for particular analogs (e.g., dopamine, ascorbic acid, uric acid), not for others (e.g., glucose), that will be helpful.
I am using screen printed carbon electrode (scpe) for cyclic voltammetry in my sensing studies. The electrolyte is PBS solution (pH=7). I got the CV for bare SCPE without much noise but after coating of the nanomaterial I couldnt get any proper response instead very high noise in the CV. I tried with two different nanomaterials and tried two different coating methods (without and with binder), but the observation is same.
I am attaching the picture of noise I got.
Please discuss your valuable suggestions for solving this issue. I haven't done any pretreatment for the scpe before coating the sample
Can we perform electrochemical detection process of analytes by only using water without any supporting electrolytes?
Iron vanadate catalyst was coated over SPCE and the EIS curve was measured in the presence of 5 mM K3[Fe(CN)6] and K4[Fe(CN)6]/0.1 M of KCl solution.
Thanks in advance!
Hello, i have a question about Cyclic voltammetry. I made planar sensor with all 3 electrodes (WE,RE,CE) with AgNP ink. Problem is when i try clean the surface with only 0.1M KCl, the current reach 100 or 1000 times more then it should. Almost same results are if there is added 5mM ferro/ferri on 0.1M KCl. I tried to use printed silver RE with classic WE (Pt) and CE (Pt) and printed silver CE with classic RE (Ag/AgCl/KCl) and WE (Pt) and current of 5mM ferro/ferri in 0.1M KCl was in expected window (under 100 uA). Then i tried printed silver WE with classic CE and RE and current was again in units of mA. My knowledge of chemistry is very low so i dont know if there is some kind of reaction.
My main question is why and what happens and if different buffer intead of KCl can work. If you can redirect me to some web page or article it would be great. Thank you.
While testing my target X, it has an oxidation potential at 0.5V. For the interference test, a mixture of my target X and an interfering ion Y was done. While running CV or DPV the oxidation potential has shifted. How to explain that?
Also, what does mean if I get a large oxidation peak instead of a sharp one?
I tried with DI water but it cannot fully dissolve melatonin.Some people suggested to use little ethanol. But i have a confusion that if i use ethanol then it may have interference duringelectrochemical detection.I need some good suggestions.
I'm trying to determine the best way to detect changing dopamine levels in primary neuronal cultures under different treatments/stresses. The literature seems very hard to follow as methods and equipment used are not explained very well. I've found that electrochemical detectors coupled to a HPLC seem to be fairly standard, but it's very difficult to understand which company is the best to buy a detector from, from ESA no longer sell? and whether they will fit with most HPLCs? Or whether this is now an out dated method and there is a better way?
Hi Research gate community,
I'm currently working on HPLC/Electrochemical detection method development for a peptide Hepcidin-25 (also known as iron regulator). After trying different gradient profiles with phosphate and acetate buffers in acetonitrile and methanol respectively, I came to the conclusion that Hepcidin-25 is not electrochemically active.
So I began searching about techniques that can be used to make amino acids and peptides electrochemical active and found that the most popular technique is derivatizing with OPA/ beta-mercaptoethanol or OPA/sulfite, for aminoacids. Although this technique was never applied to peptides, I'm willing to try and check if some amino acids in the peptide are going to be derivatized. Biuret's method was found to be successful for peptides, but it was never used with HPLC and required a very high potential to oxidized for some peptides.
Does anyone know if there are any other methods that may be worth exploring to make this peptide electroactive? or otherwise, I have no option but to collaborate with labs equipped with HPLC-MS/MS.
Thanks in advance!
Amino acid sequence of Human Hepcidin 25 is:
Mobile phases combinations tried:
(A: 50 mM NaH2PO4 (pH~2) in water, B: 100mM NaH2PO4/ acetonitrile/methanol 30/60/10 (v/v/v) pH~2) and
(A: 100 mM Lithium acetate in water, B: 100 mM Lithium acetate/ methanol/ acetonitrile 10/80/10 (v/v/v))
Column: C18, 4.6 mm x 250 mm, 5 um, 300A
First, i coated Hexanedithiol on to the gold surface and then blocking remain gold surface used Mercaptohexanol. After that Benzoquinone was coated on gold surface. We reduced the benzoquinone using electricity. Finaly, thiolated peptide was coated on to the gold. And measured using SWV.
(Buffer-4mM Fe(CN)3-/4- )
Question 1. We can't observed clean peak in SWV. How can i get a clean peak?
Question 2. Some research papers suggest that SWV should measured many times to get stable and clean peaks. Is this suggest
Thank you for interest to my questions.
I have seen many researchers including Prof Alan Bond measure the effective areas by measurement of the peak current obtained as a function of scan rate under linear sweep voltammetric conditions for the one-electron oxidation of Fc [1.0 mM in CH3CN (0.1 M Bu4NPF6)] or reduction of [Fe(CN)6] 3- [1.0 mM in water (0.5 M KCl)] and use of the Randles-Sevcik equation.
The classic IUPAC paper (Trasatti and Petrii 1991, https://www.sciencedirect.com/science/article/pii/002207289280162W) provided us with some other important recommendations in different conditions (one example is via reduction of gold oxide)!
I would like to know whether there are any disadvantages of using the Randles-Sevcik equation for measuring the area? Do you prefer any other methods over this one while working with a reversible reaction on gold disk electrode?
We have synthesized graphene foam via hydrothermal route. When we carry out electrochemical tests in the KOH solution,
the foam gets fragmented. Is it possible to use a Carbon conductive adhesive tape to fix the foam?
I would appreciate if any one could help.
I am looking for information regarding Differential pulse voltammetry method to detect organic contaminant using nano biosensor, .... i have also question regarding their advantages to other methods such as USING GC and GCMS.
What is its strong feature?
i need some quantitive source and information to compare its cost and accuracy and its process of dpv to gc.
Hello, we are using the method described here,
After incubation with beads and HRP and magnetic isolation, we wash three times with five times the reaction volume using 0.5% Triton in PBS.
We repeated, using molecular grade water as our product, eliminating BSA in our SA-HRP diluent, since BSA can contain biotin. This increased background.
We repeated again and increased BSA in our SA-HRP diluent. This helped a bit, but we still see high background.
Could the beads and HRP be interacting with each other causing the background? Something else?
Thank you in advance!
I read two research papers regarding electrochemical detection of two analytes: potassium ferrocyanide and hydrogen peroxide. I notice that the resulting i-t curve for each experiment looks different from the other. Why is that ( potassium ferrocyanide samples generate a rapid current increase followed by a rapid current decrease while H2O2 samples generate a rapid current increase followed by a graduate current decrease)? Also, how can I integrate the charge values for the hydrogen peroxide curve, in term of integration limits? I attached an image that shows both curves.
I work on the determination of the three component system of heavy metal ions (Pb2+, Cu2+, Cd2+) in water by an anodic stripping voltammetry technique on a thin film of mercury on the glassy carbon electrode. According to my observations, there is no interference between the determination of such metal ions. I have some samples that were in contact with an adsorbent. After adsorption equilibrium, the solution was separated. I want to know how much of the mentioned metals are retained in the solution. My advisor insisted on the standard addition of three metals in sperate runs, and it will be so tricky because of the high number of samples. Do I want to know what if, all three metals added simultaneously in the standard addition process?
Recently, I have been working on AOR. I have obtained interesting results, however, the result is a bit disturbing as it comes with noise in the curve. Below is a picture of such. I have read up some of the suggestions presented to similar circumstances in RDE measurement for ORR. I have not been able to overcome the challenge. For my circumstance, am working using Pt wire/coil as counter, Ag/AgCl as reference and GC as working electrode in 1M NaOH.
1. No leakage in RE as I have checked a couple of times and I have about 3 of these REs at my disposal, so I can interchange and check if there is any leakage (issues) with either of them. The aligator clips look good and have also interchanged with spare.
2. No mechanical vibration / interference as the lab is set up in the basement of the building and the experimental setup is on a standardized experimental bench. In addition, am not working on a hanging electrode.
3. From the picture, I have worked between -0.7eV and 0.6eV. However, I do work also in the range of 0eV and 1.4eV
4. The experimental solution has been prepared hours prior to the the measurement, and given enough time to acclimatize to the room temperature. As regard to the GC electrodes, I follow the standard rules. Polishing via the "8" pattern using 0.05um polishing alumina once in 5 days on the polish and DIW for rinsing.
Do you have any other suggestion?
Why the amperometic curve (under stirring condition) will has perfect straight line (Figure 1) but some of them will have slanted line (Figure 2) ?
The current of oxidation of analyte (Electroactive sp.) in amperometric curve should decrease after the increement as the analyte is oxidized by the modified electrode and the concentration of analyte is decreasing?
Please advise. Thanks.
I'm looking to improve the sensitivity of a mediated carbon electrode. The mediating compound is being added via solvent casting post electrode printing, so any additional treatment/ modification can be applied at any stage.
So far I have tried using MWCNTs, Pyyrole, nafion, and various potentials of anodisation using NaOH, and cycling in H2SO4.
Can anyone suggest other methods/ protocols that may improve my electrode sensitivity without creating too much background?
My work is on biomolecule sensing by potentiometry (CA, CV, etc.). Concentration of each individual biomolecule can be easily monitored by variation in current or voltage, but how to check selectivity i.e. which specific biomolecule is present in a mixture of different biomolecules. In case of heavy metals the redox potential difference is high which is not the case in biomolecules. So please suggest me how to sense or discriminate specific biomolecule (ex. amino acid).
I'm performing a photolytic reaction that liberates a species that is electroactive and detected amperometrically on a Pt electrode. The illumination occurs directly on the Pt working electrode and results in an increase in background current even when evaluating a blank sample.
Is this due to photocurrent in the Pt working? I thought this was more prevalent in semiconductors. Or perhaps it's photoelectric effect?
I want to reduce NaBO2 to NaBH4 on a catalyst (electrode). Kindly provide me suggestions of how can I confirm that the reduction of NaBO2 to NaBH4 is taking place or not?
We use this acid bath to clean electrochem glassware. A recently prepared one has turned faint yellow after 3 or 4 uses. We've been trying to rule out possible sources of contamination. Could KCl contamination be the cause?
The material or compound could be in solution from where it could be electro-deposited onto a second surface but the deposited layer of material from solution becomes non-conducting after deposition.
Various methods as finding capacitance have already been discussed in some papers but it seems that reliable figures and data is not available. BET is out of question as metal catalyst is carbon supported. Is there any other method that could be used to determine the electroactive surface area of non-noble metals.
I'm calibrating Hg/Au amalgam electrodes for Fe(II) in redox analysis. Based on literature, I should be able to do this at 100 mV/s scan rates with a 100nA/V sensitivity. However, this rate is too noisy. While reducing my scan rate to 10 mV/s helped with noise, I still have a peak issue. I should be seeing a peak around -1.5 to -1.4 V, and instead its closer to -1.6 V. Is this an issue with a faulty Ag/AgCl reference trode? Or a Working Electrode polishing issue? I plated using 0.16M Hg(II)Cl2. Or even my supporting electrolyte? (0.02 M NaCl)
I have arsenic precursors like arsenic tirioxide, i need to prepare AS(III) solution for the electrochemical detection. Is it need to dilute arsenic precursor in acid to make AS(III)? or else we can use any base? If we need to use acid or base what is the required concentration of acid or base in the preparation?
What is the difference of a species preadsorbed at the electrode and having the species suspended in the electrolyte?
i am working on electrochemical detection of DNA and proteins after adsorption of Fc-DNA probe or Fc-aptamers on reduced graphene oxide modified electrodes. But, the sqaure wave voltammetry signal is not stable with time. always there is 5 to 10% decrease in the swv signal which cannot be used for further measurement. does anyone saw this issue before and how can we figure out it. many publications have been published in this field bit none talk about the stability of the adsorbed DNA containing redox tag.
hello everyone, I am a beginner in the field of biosensors and I am working on rGO based SPE for glucose detection. I am facing some problems such that the redox peaks are occuring in the negative potential and the peak to peak seperation is too high than 59 mV. what are the possible reasons? Need some expert advise. please find the attachment
Because, I am getting negative intercept for my dopamine sensor (diffusion controlled process). When i am plotting the peak current vs square root of scan rate, i am getting negative intercept. But when i plot with scan rate it shows positive intercept. So, what is reason behind this, and what the intercept stands for......
I'm going to try an electroanalytical methodology for sucralose determination. Sucralose is a sugar substitute, in fact, a sugar-like substance with three chlorine atoms instead of hydroxygroups.
How can I modify a conducting polymer, in order to immobilize covalently the sucralose molecule?
I found it for Cyclic Voltammetry (Peak intensity is proportional to the square root of the scan rate), but not for DPV...
I am working on electrochemical sensing of metals using Square Wave Stripping voltammetry, I am getting good results ( prominent peaks of analytes) but also there appears peak between 2-4 mV vs. SCE when there is no analyte in system. Is there any method for base-line correction???
My WE is GCE modified with Au-NPs, RE is Calomel 3.5 M KCl, Pt as CE. I am using ultrapure water for buffer synthesis. Do clean cell and WE carefully i am very confused how to remove this error.
What should i do?
I have got Rct value of bare GCE of 80 kohm cm2. Please help me to explain why Rct value is high for bare GCE?
here I have used 3 electrode system, with different types of electrodes such as 6M KOH, 5M NaCl and electrodes are graphene coated Nickel Foams. Is this same potential window can be applied for the CV as well as GCD? I want to know the way how to find out this potential window
I was trying to polymerize aniline onto GCE and use for heavy metal detection. But the modified GCE shows a huge oxidation peak in square wave stripping voltammogram and none of the metal ions oxidation peak can be observed. But similar sensor has been established and published with successful detection of Pb.
I'm using three electrodes system with GCE, Ag/AgCl, Pt wire for CV and SWSV. Here is what I have done:
1). CV polymerize aniline onto GCE in 0.1M H2SO4 for 10 cycles using classical parameters for polyaniline.
2). Dip modified GCE into distilled water for 3 mins for removal of monomer if any.
3). Put modified GCE into spiked testing solution and run SWSV with 300s pre-depo. time and other classical parameters for Pb detection.
Graphs showed below are 1)untreated GCE in testing solution with 10ppb Pb. 2)Modified GCE in exact same testing solution in 1). 3)A typical voltammogram for polyaniline modified GCE for Pb detection.
My question is:
1) What may cause the oxidation peak in graph 2.
2) If it's related to the CV of aniline, how can I get rid of it? Or how can I make sure that the surface treatment is stable and won't get oxidized in following testing procedure?
I have prepared supercapacitor electrode. Its is Graphene Oxide coated on Ni foam.
I measured it within three electrode system. Pt electrode as counter electrode and Ag/AgCl electrode as reference electrode, connected them manually in 6M NaOH electrolyte solution. I have tried the cyclic voltammetry in 1 V difference but CV curve is not square shaped. When I reduce the voltage difference up to 0.6 V its starting to given the square shape and further decrement (0.3 V) its given the ideal CV curve.
I need your comment about this matter, I fell this small voltage gap is not enough for publication. Using your experience anyone can comments what should I improved in my electrode ?
I am not fully clear about the experimental procedures to do stochastic microsensing and how to interpret the patterns obtained from the stochastic microsensor. I would appreciate as detailed analytical information as possible.
Thanks in advance.
I'm working with a L3Mo(0)(CO)3 complex. Performing CV at acidic pH with 0.1 M, I observe a reversible MoI/0 couple. Shifting to basic conditions by the addition of NaOH, I observe a large irreversible oxidation. I can add HOTf to shift the pH back to <7 and can recover my reversible couple, almost completely. What process could be occuring under alkaline conditions? I initially though it might be decomposition to Mo-oxide. How could I probe this? Thank you for any help or insight you can offer.
Hi All, I deeply appreciate any suggestion for a cost effective method to measure sulfur compound during sulfidic spent caustic treatment by electro-fenton method? Is there any colorimetric method rather than chromatography analysis?
I had fabricated a oxide based thin film over metal layer. We have electrochemical workstation in our lab.
1)On what basis i had to set the voltage range for CV curve
2)Is there any standard values for a material to achieve like this much capacitance is needed at this area to be a good capacitor
3)Can any other test regarding capacitor can be done using electrochemical workstation? If yes I also need the basics and experimental methods.
Thanks a lot in advance
We are a new research group in Electrochemsitry at Universidad de Lima in Peru. We currently do not have resources to buy a new potentiostat, so ask if any of your groups has a potentiostat that is no longer used and is in good condition for CV measures. We could take care of the shipping and others.
Hi everyone, we are having an issue with our Dionex ICS 5000. We are analysis phenol levels in alcohol samples from different distilleries within the company using HILIC and electrochemical detection (glassy carbon electrode) and gradient elution. We were running our samples very happily on an old Dionex ICS 500 machine, but about a year ago we upgraded to the ICS 5000 and have had issues with peak height in our phenol analysis ever since. Basically our peak heights sequentially drop with each sample we run until no peaks are detected (this only happens with phenols and not with our carbohydrate analysis on the same system but with a different column and eluents). We have tried everything from multiple different cleaning methods for the glassy carbon electrode, changing both the reference and glassy electrodes, changing the detector, buying new reagents, changing the column, and getting thermo involved and nothing has worked. We are now back to using the old ICS 500 as it has never had this issue. Thermo don't seem to have any idea of what could be the cause either. Can anyone help? Many thanks
I quantifying the Dopa mine,Serotonin,Norephinephrin by HPLC with Electrochemical detection (ECD). I want quantify Epinephrine Acetylcholin,GABA,Glutamate,endorphin and Histamines.
I have been trying to use inNO Model-T from Innovative Instruments Inc. in order to detect NO release from some nytrosil ruthenium (II) coordination complexes, but a lot of problems have happened. The background is very noisy and the sensibility of the sensors is very low. I have followed all the instructions provided by the manufacturer, but it was no use. What can I do? I have noticed the manual of the detector says there is a Potential Measuring Cable which allows you to correct the potential applied by the device. Do this work?
I will use it to find MA and SA, respectively. Can be the mass-transport correction equation used for it? for example i-1 = iD*imeasured/iD-imeasured. But there is no a plateau in OER polarization curve. How can I find kinetic current for OER? Thank you all.
what are the functionalization details and how would be the device fabrication?
Our chemistry department just acquired a Gamry Interface 1000 for electrochemical detection. We also bought a Dr. Bob's cell to start learning how to use the potentiostat. I want to know what simple RedOx reactions I could try with this cell just to get a sense of how the potentiostat and the electrodes work. Any help will be really appreciated. Thanks!
I want to apply magnetic field in the three electrode system (Electrochemical cells), field strength is 720. G or 0.072 T, any one can help for this?
I have gone through few methods to hydroxylise the polysilicon surface as the following:
- Fenton reaction
- boiling in HNO3 1hr
- 1:3 (H2SO4:H202) 90c
Are these methods good for hydroxylating polysi surface? Or is there any other good method for this process?
I fabricated elecrtochemical biosenser for glucose detection and i showed the response time but i can not understand the reviewer comment of (A comment on the time constant of the sensor response would also be helpful for comparison). from the i-t test i showed the respons time but i coiuld not understand what maening time constant of the sensor response?
one of the reviewer asked Why the Fe-O band shifted from Fe3O4 to magnetite- prussian blue (PB)?
I characterize Fe3O4 and composite Fe3O4 PB nanoparticles by IR and the result of Fe3o4 showed absorption peak of Fe-O bonds at 573 cm-1 and for IR of composite Fe3O4-PB it showed absorption peak of Fe-O bonds at 596 cm-1. according to the literature both band attributed to the Fe-O bonds.
so he asked why there is defferent in the bans of Fe-O in Fe3O4 and Fe-O band in composite Fe3O4-PB?
Also he asked why there is no negative transmittance in IR spectra?
Iam accaching the FTIR spectra of pure Fe3O4 nanoparticles (a) and magnetite PB nano-composites (b).
I have been using HPLC UV methods for some amines, now i am willing to switch over to electrochemical detection, but the LOD i'm getting is same as UV detector. i'm not able to detect below 50 ng/ml concentration. May you please share your experience with HPLC -ECD? what modifications in ampreometric analysis can enhance the signal of ECD?
I am trying to formulate a relationship to convert the corrosion current density (micro amperes per sq. centimeter) to penetration depth (millimeter per year).
Could someone help me out how this conversion is made?
Thank you so much.
I have a question regarding gradual I-V curve in ReRAM. Actually the Top and bottom electrodes are Au and ITO, respectively. The insulator is polymer but I got gradual curve, what should be the inferred switching mechanism considering that Au is not an active electrode? In log-log plot it shows ohmic contact with slope of 1.2, but I think it shouldn't be filamentary because the change is not abrupt.
Would you please give me a comment?
I am working electrochemical Immunosensor for detection of protein (toxin).I am modified GC electrode surface for cobalt phthalocyanine as redox mediator than Immunosensor reaction of antibody and antigen interaction reaction.100ng to 1 ng detection I got signal. But zero concentration of protein also given signal Why? How to solve the problem. Can you give me advice?
I'm gonna ask the experts in electrochemical corrosion testing. when I get corrosion rate from electrochemcial test such as Tafel test or Rp/Ec trend, is that exactly the corrosion rate estimation in that type of material or just as indication for corrosion process ? especially we use accelerated tests. and I read some question answers here imply the corrosion rate from polarization resistance maybe will be different from another test because the corrosion depends on the time.
Thanks in advance
Related to Insitu electrochemical detection
non-enzymatic electrochemical sensor, modified electrode
I am trying to detect arsenic using MnOx/Au nanocomposite by LSVAS using following parameters.
Vdeposition = -0.7 V
Stripping V= -0.6 to 0.3 V
scan rate = 100mV/sec
Electrolyte: Carbonate buffer (pH = 10)
But I am not getting results specific to As in stripping scan (results attached). Also I am not seeing any peaks specific to As (III) oxidn/reduction in CV as well.
If the linear range for an electrochemical sensor is 700 nM - 300 M how to calculate limit of detection for the same
Please specify it in detail
Is there any standard protocols which is reproducible for detection of DNA on any form of electrodes. I see tons of papers on electrochemical detection of DNA but does someone have any experience reproducing the results from any paper? I mean I have seen people using PBS, acetate buffer and also mediators like ruthenium & methylene blue. Anyone have any experience with getting any of these?
I record ORR by RDE method. My the current density for ORR usually ranges 4-5 mA/cm2 at 1600 rpm in acid or basic electrolyte. However, the current density appears near 6 at mA/cm2 at 1600 rpm in some good papers. I want to try to get tha same current density with those papers. What is wrong with my experiment? Please tell me some comments on it. Which flow rate of oxygen during measurement is suitable?