I am trying to estimate the concentration of a biomolecule in presence of proteins using cyclic voltammetry. Due to interferences posed by proteins, the sampling volume has been diluted around 10 times. however due to the extensive dilution, the current signals are fluctuating. Is there any parameter or technique that can minimise this variation
Is it possible to mention what are the components present in your electrolyte and what electrodes are you using?
I am using disposable screen printed electrode and the supporting electrolyte is sodium chloride.
Just a question regarding the dilution : What is your total sample volume ? What is the molarity of the buffer / protein in that volume ?
The total sample volume is around 300uL and biomolecule concentration is of micro molar concentration
varying the scan rate we can minimise the variation and no need of this much dilute concentration and maintain inert atmosphere... you will get good results.
Have you treated your SPE using plasma before use? That will increase sensitivity of the electrode.
Stirring can make a big difference, I'm not sure if you already are doing that
Hi,
I understand that dilution was made with buffer or with NaCl,... because if it was made with water, conductivity decreases. It is better to use higher ionic strength.
Good luck,
Teresa
Yes the dilution was done using NaCl but even then the coefficient of variation is more than 15%
I also understand that you are using disposable electrodes, to have similar protein adsorption and then, electrode area.
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