Electrochemical sensors based on platinum electrodes modified with hybrid inorganic–organic coatings for determination of 4-nitrophenol and dopamine

New electrochemical sensors for dopamine (DA) and phenol derivative, based on hybrid inorganic redox material-organic conducting polymers, were developed. Hybrid inorganic–organic coatings based on Prussian blue, polyazulene, poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3-[(E)-2-azulene-1-yl)vinyl]thiophene) have been prepared by electrochemical methods in various configurations onto Pt substrate. Dopamine and 4-nitrophenol (4-NP) have been determined by square wave voltammetry using both mono and bilayer modified electrodes. The modified electrodes exhibited a linear response over wide range of 4-nitrophenol concentrations from 30 to 90 μM, with a detection limit of 8.23 μM (s/n = 3). A linear trend for the responses for dopamine concentrations ranging from 2 to 100 μM, with a sensitivity of 0.116 μA/μM, has been also obtained.