Here we report the synthesis of a novel conducting polymer and its properties as an immobilization platform for biosensor application. The conducting polymer has functional groups used for the formation of amide bonding with the enzyme immobilized on the polymer surface. After covalent immobilization of glucose oxidase (GOx) on the polymeric matrix, its application for glucose biosensing was investigated in detail. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to monitor the surface properties of the polymer before and after biomolecule conjugation. The optimized biosensor showed a very good linearity between 0.01 mM and 1.2 mM, a 13 s response time and a detection limit (LOD) of 0.004 mM to glucose. Also, kinetic parameters, operational and storage stabilities were determined. Apparent Michaelis constant (K m app ) and I max values of 1.17 mM and 11.28 mA, respectively, were obtained.

Poly(2-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) (SNS) acetic acid) was electrochemically deposited on graphite electrodes and functionalized with lysine (Lys) amino acid and poly(amidoamine) derivatives (PAMAM G2 and PAMAM G4) to investigate their matrix properties for biosensor applications. Glucose oxidase (GOx) was immobilized onto the modified surface as the model enzyme. X-Ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used to report the surface properties of the matrices in each step of the biosensor construction. The biosensors were characterized in terms of their operational and storage stabilities and the kinetic parameters (K(app)(m) and I(max)). Three new glucose biosensors revealed good stability, featuring low detection limits (19.0 μM, 3.47 μM and 2.93 μM for lysine-, PAMAM G2- and PAMAM G4-functionalized electrodes, respectively) and prolonged the shelf lives (4, 5, and 6 weeks for Lys-, PAMAM G2- and PAMAM G4-modified electrodes, respectively). The proposed biosensors were tested for glucose detection on real human blood serum samples.

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