I'm trying to electropolymerize the pyrrole monomer onto the surface of SPCE surface using Cyclic voltammetry (-0.7 -+0.7V) but apparently, the preliminary measurments of SPCE/PPy are not good. (The background obtained using SPCE/PPy is very high compared to SPCE which could be due to the high amount deposited of Pyrrole onto SPCE surface)
Could you please suggest me some protocols which allow me to avoid such problem.
Many thanks
Abdellatif Ait Lahcen,
Hi Abdellatif
You should know that polypyrrole has its desire and undesired properties together. For example its high background current is an unfavorable trait of polypyrrole, at least in sensor application it is so.
But if your analyte of interest has such properties like aromatic rings or proper surface charge and so on polypyrrole will be able to drag your analyte more close to electrode surface and increase its electrochemical signal by decreasing mass transfer limitations, Rmt.
If you need to decrease background current there are some methods like changing your electrolyte which is used for electropolymerization because type of its anion, amount of its charge and size, has a great influence on background current of obtained polypyrrole. Secondly, you can overoxidize polypyrrole by exerting a more positive potential in a proper solution. Overoxidized polypyrrole is very useful specially for analytes which have negative surface charge.
In fact, background currents of conducting polymers such as polypyrrole,polyaniline, poly(3,4-ethylenedioxythiophene), and their derivatives are very high due to capacitance characteristics and high conductivity.The overoxidization or dedoping can decrease background current, but chemical structure and conductivity was were destroyed.
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