Gold nanoparticle-polyaniline composite films for glucose sensing

Gold nanoparticles (AuNPs) have been self-assembled onto electrochemically deposited polyaniline (PANI) films on indium-tin-oxide (ITO) coated glass plates to fabricate glucose biosensor. The covalent immobilization of glucose oxidase (GOx) in the near vicinity of gold nanoparticles has been obtained using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS), chemistry between amino groups of PANI and COOH groups of GOx. These AuNPs-PANI/ ITO and GOx/AuNPs-PANI/ITO composite films have been characterized using Fourier transform infra red (FTIR) and cyclic voltammetry (CV) techniques, respectively. The fast electron transfer from the modified PANI surface to electrode is indicated by the observed increase in amperometric response current of these GOx/AuNPs-PANI/ITO bioelectrodes. These GOx/AuNPs-PANI/ITO bioelectrodes exhibit response time of 10 s, linearity from 50 to 300 mg/dl and show value of apparent Michaelis-Menten constant (Km(app)) of 2.2 mM.