Aligned carbon nanotubes on quartz substrate for liquid gated biosensing

• Published in: Biosensors & bioelectronics Vol. 25; no. 8; pp. 1989 - 1993
• Main Authors: Palaniappan, Al, Goh, W.H., Tey, J.N., Wijaya, I.P.M., Moochhala, S.M., Liedberg, B., Mhaisalkar, S.G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.04.2010; Elsevier
• Subjects: Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensor; Biosensors; Biotechnology; Equipment Design; Equipment Failure Analysis; Field effect transistor; Flow Injection Analysis - instrumentation; Fundamental and applied biological sciences. Psychology; Immunoassay - instrumentation; Liquid gating; Methods. Procedures. Technologies; Microfluidic Analytical Techniques - instrumentation; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - ultrastructure; Prostate-Specific Antigen - analysis; Quartz - chemistry; Reproducibility of Results; Sensitivity and Specificity; Single walled carbon nanotube; Transistors, Electronic; Various methods and equipments; Field effect transistor; Liquid gating; Single walled carbon nanotube; Biosensor; Substrate; Nanotube; Quartz; Carbon
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2010.01.009

A facile and high performance biosensing platform using aligned carbon nanotubes on quartz substrate is reported in this communication. Single walled carbon nanotubes are grown on quartz substrates by a chemical vapor deposition process and are characterized with field emission scanning electron microscopy and atomic force microscopy in order to verify the quality of the material. The quartz substrate is then directly used as a biosensor in a field effect transistor configuration. In order to demonstrate the sensing capabilities of the fabricated sensor devices, electronic detection of prostate specific antigen, a potential cancer biomarker, is carried out by adopting liquid gated configuration. A conductivity change due to the specific binding of target antigen with the immobilized receptor antibody demonstrates the sensing capabilities of the fabricated device. Sub-nM detection sensitivities have been obtained using the adopted direct immunoassay approach, which shows that the device responds to clinically relevant concentration regimes.