Nanostructured conducting polymer based reagentless capacitive immunosensor

• Published in: Biomedical microdevices 2010-02, Vol.12 (1), p.63-70
• Main Authors: Bandodkar, Amay Jairaj, Dhand, Chetna, Arya, Sunil K, Pandey, M. K, Malhotra, Bansi D
• Format: Article
• Language: English
• Subjects: Biological and Medical Physics; Biomedical engineering; Biomedical Engineering and Bioengineering; Biophysics; Biosensing Techniques - instrumentation; Biosensors; Electric Capacitance; Electric Conductivity; Electrochemistry - instrumentation; Engineering; Engineering Fluid Dynamics; Equipment Design; Equipment Failure Analysis; Immunoassay - instrumentation; Immunoglobulin G - analysis; Immunoglobulins; Indicators and Reagents; Miniaturization; Nanostructured materials; Nanostructures - chemistry; Nanostructures - ultrastructure; Nanotechnology; Nanotechnology - instrumentation; Polymers; Polymers - chemistry; Reproducibility of Results; Sensitivity and Specificity
• ISSN: 1387-2176; 1572-8781
• DOI: 10.1007/s10544-009-9360-2

Nanostructured polyaniline (PANI) film electrophoretically fabricated onto indium-tin-oxide (ITO) coated glass plate has been utilized for development of an immunosensor based on capacitance change of a parallel plate capacitor (PPC) by covalently immobilizing anti-human IgG (Anti-HIgG) using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide chemistry. These fabricated PANI/ITO and Anti-HIgG/PANI/ITO plates have been characterized using scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry and Fourier transform infra-red studies. The capacitance measurements indicate that dielectric medium of this biologically modified PPC (Anti-HIgG/PANI/ITO) is sensitive to HIgG in 5 − 5 × 10⁵ ng mL⁻¹ range and has lower detection limit of 1.87 ng mL⁻¹. The observed results reveal that this Anti-HIgG modified PPC can be used as a robust, easy-to-use, reagentless, sensitive and selective immunosensor for estimation of human IgG.