A novel thin film urea biosensor based on copolymer poly(N-3-aminopropylpyrrole-co-pyrrole) film

The enzyme, urease (Urs), was covalently immobilized to an electrochemically prepared novel copolymer poly(N-3-aminopropylpyrrole-co-pyrrole) (PAPCP) film onto an indium-tin-oxide (ITO)-coated glass plate for the fabrication of urea biosensor. The urease enzyme retains its bioactivity when being immobilized on N-substituted pyrrole polymer film by covalent bonding. The biosensor was characterized with infrared and scanning electron microscopy. Potentiometeric response was measured as a function of urea concentration in Tris-HCl buffer (pH 7.0). The electrode showed a linear response range of 6.3×10−6 to 4.07×10−4 M urea. The biosensor exhibited a response time of 25-50 s, reaching to a 95% steady state potential value, and was stable for about 2 months.