Publication details

Authors: Ramanathan, Madhumati; Patil, Mitali; Epur, Rigved; Yun, Yeoheung; Shanov, Vasselin; Schulz, Mark; Heineman, William R.; Datta, Moni K.; Kumta, Prashant N. 
Title: Gold-coated carbon nanotube electrode arrays: Immunosensors for impedimetric detection of bone biomarkers 
Type: Journal Article 
Publisher: Biosensors and Bioelectronics 
Year: 2016 
Volume: 77 
Start Page: 580 
End Page: 588 
DOI: 10.1016/j.bios.2015.10.014 
Abstract: C-terminal telopeptide (cTx), a fragment generated during collagen degradation, is a key biomarker of bone resorption during the bone remodeling process. The presence of varying levels of cTx in the bloodstream can hence be indicative of abnormal bone metabolism. This study focuses on the development of an immunosensor utilizing carbon nanotube (CNT) electrodes coated with gold nanoparticles for the detection of cTx, which could ultimately lead to the development of an inexpensive and rapid point-of-care (POC) tool for bone metabolism detection and prognostics. Electrochemical impedance spectroscopy (EIS) was implemented to monitor and detect the antigenantibody binding events occurring on the surface of the gold-deposited CNT electrode. Type I cTx was used as the model protein to test the developed sensor. The sensor was accordingly characterized at various stages of development for evaluation of the optimal sensor performance. The biosensor could detect cTx levels as low as 0.05 ng/mL. The feasibility of the sensor for point-of-care (POC) applications was further demonstrated by determining the single frequency showing maximum changes in impedance, which was determined to be 18.75 Hz. 
Keywords: CNT, Gold nanoparticles, Immunosensor, Impedance, C-terminal telopeptide, Bone marker