Amperometric enzyme biosensor based on the glucose oxidase (GOx) incorporated polyaniline nanowires (PANI-NWs) on carbon cloth (CC) electrode was demonstrated. The simple, direct-growth of PANI-NWs on CC, via electrochemical polymerization, provides free-standing, template-independent, hence almost (interfacial) defects-free nanostructures. The defect-free interfaces, along with the excellently sensitive organic nanostructured-surface, as evident from its significantly large effective surface area (24 times the geometric area) for redox-sensing, allows efficient entrapment/immobilization and sensing of biomolecules, via rapid electron-transfer at NWs-CC. The GOx-immobilized PANI-NWs/CC, even in initial unoptimized stage, exhibited an excellent sensitivity, similar to 2.5 mA mM(-1) cm(-2), to glucose, over detection range 0-8 mM, adequate for clinical monitoring of human glucose levels. The report clearly reveals a cost-effective simple system possessing enormous potentiality for biosensors, bicrenergy and bioelectronics applications. (C) 2009 Elsevier B.V. All rights reserved.