Biosensors and Bioelectronics 26 (2011) 2811–2821 Contents lists available at ScienceDirect Biosensors and Bioelectronics journal homepage: www.elsevier.com/locate/bios Review Recent advances in polyaniline based biosensors Chetna Dhand a,b , Maumita Das a,b , Monika Datta b , B.D. Malhotra a,∗ a Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, Materials Physics and Engineering Division, National Physical Laboratory (Council of Scientific and Industrial Research), Dr. K.S. Krishnan Marg, New Delhi 110012, India b Department of Chemistry, University of Delhi, New Delhi 110007, India article info Article history: Received 9 August 2010 Received in revised form 30 September 2010 Accepted 11 October 2010 Available online 16 October 2010 Keywords: Biosensor Polyaniline Conducting polymers Direct electron transfer Nanostructure Immunosensor abstract The present paper contains a detailed overview of recent advances relating to polyaniline (PANI) as a transducer material for biosensor applications. This conducting polymer provides enormous opportu- nities for binding biomolecules, tuning their bio-catalytic properties, rapid electron transfer and direct communication to produce a range of analytical signals and new analytical applications. Merging the specific nature of different biomolecules (enzymes, nucleic acids, antibodies, etc.) and the key properties of this modern conducting matrix, possible biosensor designs and their biosensing characteristics have been discussed. Efforts have been made to discuss and explore various characteristics of PANI responsible for direct electron transfer leading towards fabrication of mediator-less biosensors. © 2010 Elsevier B.V. All rights reserved. Contents 1. Introduction .......................................................................................................................................... 2812 2. Polyaniline ........................................................................................................................................... 2812 2.1. Structure of PANI ............................................................................................................................. 2813 2.2. Conductivity in PANI ......................................................................................................................... 2814 2.3. PANI: an efficient material for biosensing application ....................................................................................... 2814 3. Classification of enzymatic biosensors based on PANI as immobilization platform ................................................................ 2816 3.1. PANI based peroxide biosensors ............................................................................................................. 2816 3.2. PANI based glucose biosensors ............................................................................................................... 2817 3.3. PANI based cholesterol biosensors ........................................................................................................... 2817 3.4. Other enzymatic biosensor based on PANI ................................................................................................... 2818 4. Classification of bioaffinity sensors based on PANI as immobilization platform ................................................................... 2818 4.1. Polyaniline based DNA biosensors ........................................................................................................... 2819 4.2. Polyaniline based immunosensors ........................................................................................................... 2819 5. Other biosensors based on PANI ..................................................................................................................... 2820 6. Commercialization and challenges .................................................................................................................. 2820 7. Conclusions .......................................................................................................................................... 2820 Acknowledgements .................................................................................................................................. 2820 Appendix A. Supplementary data .................................................................................................................... 2820 References ........................................................................................................................................... 2820 ∗ Corresponding author. Tel.: +91 11 45609152; fax: +91 11 45609310. E-mail address: bansi.malhotra@gmail.com (B.D. Malhotra). 0956-5663/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.bios.2010.10.017