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Measuring sensor sensitivity

  1. Oct 9, 2009 #1
    I am developing a new chemical sensor. I want to test the sensitivity of the sensor to various chemicals such as K3Fe(CN)6 and Ascorbic Acid. My understanding was that you could use a chronoamperometry scan to do this measurement by injecting a controlled amount of chemical every 60 seconds and recording the increase in steady state current observed after 15-20 seconds. This gives a stair step looking graph when the data is plotted. However, when I tried the experiment tonight, I couldn't get any meaningful data. All I could see in the data was noise. Here is my setup:

    Gamry FAS1 Potentiostat
    Pt wire Aux Electrode
    Orion Single Junction Ag/AgCl Reference electrode
    Pt disc electrode

    I was trying to measure K3Fe(CN)6 in 0.1M KCl. The K3Fe(CN)6 concentrations increased from 1uM to 10mM logarithmically. I can get a good result with a CV scan so I know that the system is connected properly and working well.

    Does anyone have experience with performing an experiment like this? Is my concentration of KCl too high. Does anyone have any other suggestions.

  2. jcsd
  3. Oct 13, 2009 #2


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    What did you have your potential set to? Hopefully it was set to a potential of one of the peaks on your CV....
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